SIM UNIVERSITY SCHOOL OF SCIENCE AND TECHNOLOGY EMBEDDED EDGE-COUPLED BPF USING MULTILAYER LTCC TECHNOLOGY FOR KABAND MULTI-CHIP-MODULE (MCM) APPLICATIONS STUDENT : SOONG WEI QIANG (N0604430) SUPERVISOR : DR LUM KUM MENG PROJECT CODE : JUL2010/ENG/003 A project report submitted to SIM University in partial fulfilment of the requirements for the degree of Bachelor of Engineering (or Bachelor of Electronics) May 2011 ACKNOWLEDGEMENT The Capstone Project Report signifies the apex of this undergraduate program. Many difficulties were encountered along the journey and great amount of determination and perseverance was needed to juggle between work and study commitments. I sincerely thank SIM University for providing me this opportunity to prove myself, offering excellent support and infrastructure essential to complete the capstone. I am also grateful to my supervisor and mentor, Dr Lum Kum Meng for his guidance throughout this period. Dr Lum often gave valuable advice which helped me overcome problems faced along the way. Despite his busy schedule, Dr Lum took great effort to organize periodic meetings and review on my progress consistently. Lastly, I will like to express my gratitude to my family and co-workers who have been supportive and understanding in times of need. ENG499 CAPSTONE PROJECT REPORT i ABSTRACT This project presents a 7th order Chebyshev Edge-Coupled Band Pass Filter suitable for 5 and 28GHz band applications using multilayer Low Temperature Co-fired Ceramics (LTCC) technology. Design procedures are clearly illustrated with examples shown to demonstrate the proposed coupling structures. Using LTCC substrate, geometric dimensions of coupled lines are calculated, followed by simulation and optimization using Agilent Advanced Design System (ADS) to obtain the desired filter response. Multilayer LTCC technology allows for micro-sized design offering spurious free performance and low insertion loss. Compared to other substrates, LTCC also offers 3-D integration and vertical stacking capabilities. Adjacent resonators can be stacked on different layers to achieve precise distance. Due to limited budget and equipment in our testing environment, an alternative material was considered. The FR4 which is cheaper and widely available was chosen as a suitable replacement for LTCC. However, the material suffers more dielectric loss over higher frequencies as compared to LTCC. The prototype design was further optimized and sent for fabrication using FR4 substrate of dielectric constant 4.7 with height 1600 m , loss tangent of 0.027. Hot Air Solder Levelling (HASL) and Organic Solderability Preservative (OSP) finishing was applied to the end product. The measurement was done using Agilent Network Analyzer E5062A available in SIM University laboratory. Adaptive sweep was applied from frequency range (10MHz - 5GHz) to observe the filter response. The readings are captured and compared with simulation results. The filter managed to achieve approximately 15% 3dB bandwidth, with an insertion loss of -10.37dB and return loss of -7.045dB at center frequency of 1.291GHz. ENG499 CAPSTONE PROJECT REPORT ii TABLE OF CONTENTS Page ACKNOWLEDGEMENT i ABSTRACT ii TABLE OF CONTENTS iii LIST OF TABLES viii LIST OF FIGURES ix LIST OF CHARTS xii CHAPTER ONE INTRODUCTION 1 1.1 Background and Motivation 1 1.2 Objectives 1 1.3 Proposed Approach 2 1.3.1 Literature Review 2 1.3.2 Simulation Phase 2 1.3.3 Technical Phase 3 1.3.4 Overall Design Flow 4 1.4 1.5 Review of Critical Skills 5 1.4.1 Essential Skill for Project Handling 5 1.4.2 Strength and Weaknesses 5 1.4.3 Priorities for Improvement 5 Project Planning 6 1.5.1 Progress Checklist 6 1.5.2 Gantt Chart 7 1.5.3 Required Resources 8 ENG499 CAPSTONE PROJECT REPORT iii CHAPTER TWO REVIEW OF THEORY AND PREVIOUS WORK 9 2.1 Literature Review on LTCC Technology 9 2.1.1 Definition of LTCC 9 2.1.2 Benefits of LTCC 10 2.1.3 LTCC Process 11 2.1.4 LTCC Applications 13 Literature Review on Microstrip Technology 15 2.2.1 Microstrip Structure 15 2.2.2 Wave in Microstrip 15 2.2.3 Effective Dielectric Constant and Characteristic Impedance 16 2.2.4 Guided Wavelength 17 2.2.5 Synthesis of W/h 17 2.2.6 Coupled Lines 18 2.2.7 Even and Odd Mode Capacitance 18 Literature Review on RF Filter Design and Methodology 21 2.3.1 Definition of RF Filter 21 2.3.2 RF Filter Types 21 2.3.3 Filter Classification 22 2.3.4 Edge-Coupled Bandpass Filter 23 2.3.5 End-Coupled Bandpass Filter 26 2.3.6 Hairpin Line Bandpass Filter 26 2.3.7 Interdigital Bandpass Filter 27 2.4 Network Analysis and Scattering Parameters 28 2.5 Advanced Design System (ADS) 29 2.2 2.3 ENG499 CAPSTONE PROJECT REPORT iv 2.6 Printed Circuit Board Finishing Techniques 30 2.6.1 Hot Air Solder Levelling (HASL or HAL) 30 2.6.2 Organic Solderability Preservative (OSP) 30 2.7 FR4 Substrate 32 2.8 Network Analyzer 32 CHAPTER THREE PROJECT SELECTIONS 34 3.1 Selection of Substrate Material 34 3.2 Selection of Filter Methodology 34 3.3 Selection of Software 34 3.4 Selection of PCB Finishing 35 3.5 Selection of Measuring Equipment 36 3.6 Selection of SMA Connector 37 CHAPTER FOUR FILTER DESIGN USING LTCC 38 4.1 Design of C-Band Filter using LTCC 38 4.1.1 ADS Setup for C-Band Filter 39 4.1.2 Dimensions of C-Band Filter 39 4.1.3 Initial Design for C-Band Filter 43 Design of Ka-Band Filter using LTCC 44 4.2.1 ADS Setup for Ka-Band Filter 44 4.2.2 Dimensions of Ka-Band Filter 45 4.2.3 Initial Design for Ka-Band Filter 49 Sensitivity Analysis (LTCC) 50 4.3.1 Effects of Adjusting Resonator Length (LTCC) 50 4.3.2 Effects of Adjusting Resonator Width (LTCC) 51 4.2 4.3 ENG499 CAPSTONE PROJECT REPORT v 4.4 4.3.3 Effects of Adjusting Resonator Line Gaps (LTCC) 52 Final Design 53 4.4.1 Final Design for C-Band Filter 53 4.4.2 Final Design for Ka-Band Filter 55 CHAPTER FIVE FILTER DESIGN USING FR4 57 5.1 Design of Filter using FR4 57 5.2 ADS Setup for FR4 Filter 57 5.3 Dimensions of FR4 Filter 57 5.4 Sensitivity Analysis (FR4) 61 5.4.1 Effects of Adjusting Resonator Length (FR4) 61 5.4.2 Effects of Adjusting Resonator Width (FR4) 61 5.4.3 Effects of Adjusting Resonator Line Gap (FR4) 62 Final Design for FR4 Filter 63 5.5 CHAPTER SIX FABRICATION AND ASSEMBLY OF FILTER PROTOTYPE 65 6.1 Gerber File Exportation 65 6.2 Assembly of Filter Prototype 67 CHAPTER SEVEN COMPARISON OF MEASURED AND SIMULATION RESULTS 70 7.1 70 Measurement of Results CHAPTER EIGHT CONCLUSION 72 CHAPTER NINE SUGGESTION FOR FURTHER WORKS ENG499 CAPSTONE PROJECT REPORT 73 vi REFERENCES 74 APPENDIX A – TACONIC CER-10 Datasheet 76 APPENDIX B – DUPONT 951 Datasheet 78 APPENDIX C – FR4-86 Datasheet 80 APPENDIX D – SMA Connector Datasheet 82 APPENDIX E – 3D-EM view and Schematic Diagrams 85 APPENDIX F – Other LTCC Designs (C-Band) 87 APPENDIX G – Other LTCC Designs (Ka-Band) 90 APPENDIX H – Other FR4 Designs 93 APPENDIX I – Meeting Logs 96 ENG499 CAPSTONE PROJECT REPORT vii LIST OF TABLES Page 1.1 Progress check list 7 1.2 Resources used for this project 8 2.1 LTCC Applications 14 2.2 Element values for Chebyshev prototype filter 25 2.3 Advantages and Disadvantages of HASL finishing 30 2.4 OSP process flow 31 2.5 Advantages and Disadvantages of OSP finishing 31 3.1 Comparison of software features 35 3.2 Comparison of different PCB finishing 36 4.1 Initial dimensions for C-Band filter 43 4.2 Initial dimensions for Ka-Band filter 49 4.3 Final dimensions of C-Band filter 53 4.4 Final dimensions of Ka-Band filter 55 5.1 Final dimensions for FR4 filter 63 7.1 Comparison between simulation and measured results 70 ENG499 CAPSTONE PROJECT REPORT viii LIST OF FIGURES Page 2.1 Embedded passive elements 9 2.2 LTCC Diagram 10 2.3 LTCC Process 11 2.4 Cutting or Slitting of green sheets 12 2.5 Via Punching and Filling 12 2.6 Alignment device (a) Plan view (b) Side view (c) Perspective view 12 2.7 Co-firing process 13 2.8 Structure of Microstrip 15 2.9 Cross sectional view of coupled microstrip lines 18 2.10 Quasi-TEM modes of microstrip pair (a) Even mode (b) Odd mode 20 2.11 Types of RF filter 22 2.12 Comparison of various filter response 23 2.13 Edge-Coupled Half Wavelength Resonator Filter 24 2.14 End-Coupled Bandpass Filter 26 2.15 Hairpin-Line Bandpass Filter 26 2.16 Interdigital Bandpass filter 27 2.17 Two port network with variables 28 2.18 Typical Bandpass filter response 29 2.19 OSP molecule types 31 2.20 Copper clad laminate FR-4 32 2.21 Large Signal Network Analyzer (LSNA) 33 ENG499 CAPSTONE PROJECT REPORT ix 3.1 Agilent E5062A Network Analyzer 36 3.2 Two-holed flanged SMA connector jack 37 3.3 Different types of SMA connectors 37 4.1 LTCC bandpass filter (a) Schematic view (b) 3-D view 38 4.2 (a) Substrate layer (b) Layout layers (c) S-Parameters settings for 5.3GHz filter 39 4.3 LineCalc for input lines (C-Band) 40 4.4 Setting of single mode 50ohms port (C-Band) 41 4.5 LineCalc for coupling lines (C-Band) 42 4.6 Initial results and layout for C-Band filter 43 4.7 (a) Substrate layer (b) Layout layers (c) S-Parameters settings for 28GHz filter 44 4.8 LineCalc for input lines (Ka-Band) 45 4.9 Setting of single mode 50ohms port (Ka-Band) 46 4.10 LineCalc for coupling lines (Ka-Band) 47 4.11 Initial Results and layout for Ka-Band filter 49 4.12 Final results and layout for C-Band filter 54 4.13 Final results and layout for Ka-Band Filter 56 5.1 (a) Substrate layer (b) Layout layers (c) S-Parameters settings for FR4 filter 57 5.2 LineCalc for input lines (FR4) 58 5.3 Setting of single mode 50ohms port (FR4) 59 5.4 LineCalc for coupling lines (FR4) 60 5.5 Final results and layout for FR4 Filter 64 6.1 Screen shot of gerber exportation from ADS 66 ENG499 CAPSTONE PROJECT REPORT x 6.2 Screen shot of gerber viewer 66 6.3 Fabrication process for multi-layer PCBs 67 6.4 Filter layers (a) Filter layer orientation (b) Gerber view (c) OSP finishing (d) HASL finishing 68 6.5 Picture of assembled filter prototype 69 7.1 (a) Agilent E8362B Network Analyzer (b) Two sets of BNC adaptors with BNC to SMA connectors 70 7.2 (a) Simulation results (b) Measured results 71 ENG499 CAPSTONE PROJECT REPORT xi LIST OF CHARTS Page 1.1 Flow of overall approach and objectives 4 1.2 Gantt chart 7 4.1 Plot of Length against Frequency 50 4.2 Plot of Width against S-Parameters 51 4.3 Plot of Spacing against S-Parameters 52 5.1 Plot of Length against Frequency 61 5.2 Plot of Width against S-Parameters 62 ENG499 CAPSTONE PROJECT REPORT xii CHAPTER 1: INTRODUCTION 1.1 Background and Motivation The huge advancement in wireless communications today prompts for higher demand in faster speed and wider bandwidth applications. However, problems arise when integrating analogue filter to a chip due to inductors giving a low quality factor at high frequencies. The Low -Temperature Co-Fired Ceramic (LTCC) comprises of dielectric and metallic conductor design produced in multiple layers. Each dielectric layer is typically not more than 0.004 inches, with relative permittivity at 10. The LTCC technology provides ease of integration between stripline based circuits and substrate material thus they are widely used in present microwave and millimetre wave applications. The advantage of high three-dimensional (3-D) integration and vertical stacking capabilities over other substrate materials greatly aids in reducing overall size and production cost. Other factors like low dielectric tangent loss and high frequency properties make it suitable for this purpose. This report presents the design of an edge-coupled C and Ka-Band wide band pass filter using LTCC technology. The co-firing process produces shrinkage making it difficult to control precise distance between two adjacent resonators needed for coupling. This issue was resolved by locating adjacent resonators on different layers, separated by LTCC tape. To add on, filter properties such as bandwidth, sharpness and insertion loss can be controlled by overlapping two adjacent resonator ends. 1.2 Objectives The main focus of this project is to design an Edge-Coupled wide BPF incorporating multilayer LTCC technology suitable for C-Band and Ka-Band Multi-Chip-Modules (MCM) applications. i. ii. iii. To understand fundamentals of LTCC technology and various RF methodology suitable for filter design. To learn ADS for design and simulation of proposed filter To develop time management skills and ensure project targets are delievered. ENG499 CAPSTONE PROJECT REPORT 1 1.3 Proposed Approach It is crucial to adopt a systematic approach towards completing the project. To ensure project objectives are met on time, three main approaches are defined and elaborated in the below sections. i. ii. iii. Literature Review Simulation Phase Technical Phase 1.3.1 Literature Review It is important to have good understanding of relevant subject topics before commencing on the project. This part will focus on intensive background study and Literature Review on the various methodology used in this project. Scope of research topic includes, i. ii. iii. iv. v. vi. LTCC Technology RF Filter Design Methodology Microstrip Technology Agilent Advance Design System (ADS) fundamentals PCB fabrication and types of finishing Functions and Usage of the Network Analyzer 1.3.2 Simulation Phase Advanced Design System (ADS) software is used to create schematics and layouts for the proposed filter prototype. One main feature of ADS is the inbuilt controller which allows the setup of s-parameters (Scattering Parameters) for simulation. Based on the results, we can conclude if the proposed filter is working to expectations. i. ii. iii. iv. v. vi. Determine the RF filter methodology to employ. Determine substrate layer and properties. Choose the operating frequency. Calculate physical dimensions such as microstrip length, width, line gaps. Model the proposed design using ADS. Analyze the filter response from ADS momentum simulation. ENG499 CAPSTONE PROJECT REPORT 2 1.3.3 Technical Phase This phase will emphasize on the improving the 1st filter design and hardware fabrication of the filter prototype using FR4 substrate. Once the filter is fabricated, measurements will be taken using network analyzer in the laboratory. Breakdown of steps required, i. ii. iii. iv. v. vi. vii. viii. ix. Determine FR4 substrate layers and properties. Set operating frequency to 1.5GHz. Calculate new physical dimensions based on FR4. Model the proposed design using ADS. Hardware fabrication Perform measurement using network analyzer. Comparison of measurement and simulation results Conclusion of results Suggestions for further improvements ENG499 CAPSTONE PROJECT REPORT 3 1.3.4 Overall Design Flow The overall approach is presented in the flowchart stated below. START (Technical Phase) (Literature Review) Background study on various methods employed for this project Further modelling of the filter design using FR-4 substrate with LTCC technology (2nd Design) (Simulation Phase) Determine substrate layers and properties Determine parameters like mesh frequency and port impedance etc Fabrication of filter prototype (2nd Design) Measure the actual results using network analyzer Determine dimensions such as line gap, width, length of strip line arrays Model the filter design using ADS (1st Design) Fabrication errors? Troubleshooting process Comparison of actual vs simulated results No Achieve Design objectives? Yes Analyze s-parameter results from ADS momentum simulation No Suggestion for improvements to enhance performance Yes Achieve Design objectives? Final product achieved END Chart 1.1 Flow of overall approach and objectives ENG499 CAPSTONE PROJECT REPORT 4 1.4 Review of Critical Skills The main challenge of a project lies in self discipline, proper planning and managing resources available to complete project goals. 1.4.1 Essential Skills for Project Handling To efficiently handle a project, essential skills are required. This section identifies key areas to improve based on strength, weaknesses and priorities. i. ii. iii. iv. v. vi. vii. viii. Knowledge in LTCC Technology Knowledge on edge-coupled filter and other RF bandpass filter design Knowledge on Microstrip fundamentals and filter implementation Knowledge on various multilayer substrate and properties Modelling of filter design using ADS Scattering Parameters (S-Parameters) response Functions and usage of Network Analyzer Project Management skills 1.4.2 Strengths and Weaknesses Identifying personal strengths and weaknesses help to mark down key areas for improvement, List of Strengths, i. ii. iii. iv. Knowledge gained from modules such as Signal and Systems, Digital Signal Processing and Wireless Communications have allowed better understanding of important project concepts. Past experience in designing a micro mouse system also help strengthen my project management skills. Various journals and reference books help provide background information and design implementation methods. Guidance from supervisor throughout the project period List of Weaknesses, i. ii. iii. iv. v. Need to have better understanding on wireless communications and filter characteristics Unfamiliar with RF filter design and LTCC technology Need to gain more knowledge on microstrip and multi-chip-module applications Need to familiarize with using ADS No prior experience in using network analyzers 1.4.3 Priorities for Improvement The following list states area of weaknesses highlighted for improvement. ENG499 CAPSTONE PROJECT REPORT 5 i. ii. iii. iv. v. vi. Must understand LTCC technology and advantages Must understand concept of edge coupled filter design Must know microstrip technology Must be able to model filter design and perform simulation using ADS Must understand the filter response and how to improve its performance Must be able to perform testing on fabricated filter using network analyzer 1.5 Project Planning This section highlights the project execution plan in stages, expected dateline and checklist for progress throughout the entire project duration. 1.5.1 Progress Checklist This checklist provides summary on the list of objectives to achieve and constantly updated in stages to make sure all bases have been covered. DATE TASK LIST CHECK LIST Literature Review Aug 10 To Sep10 1. Background research and Literature review on the following topics: i) ii) iii) iv) v) LTCC technology RF Filter Design Methods Microstrip Technology Advanced Design System (ADS) Fundamentals Functions and Usage of the Network Analyzer 2. Project Proposal Submission Simulation Phase Sep 10 3. Functions and Usage of Advanced To System Design (ADS) Dec 4. Modelling of filter prototype using 10 ADS (1st Design) 5. S-Parameter Simulation 6. Interim Report Submission Technical Phase ENG499 CAPSTONE PROJECT REPORT 6 Jan 11 7. Further modelling of filter design To using FR-4 substrate (2nd Design) Feb 11 8. Hardware fabrication using FR-4 substrate 9. Measurement of actual filter response using network analyzer 10. Comparison of measured and simulation results 11. Conclusion. Achieved project objectives? Mar 11 To Jun 11 12.Suggestions for improvement 13. Capstone Project Submission 14. Preparation of Poster 15. Oral Presentation further Report Table 1.1 Progress check list 1.5.2 Gantt Chart The Gantt chart below summarizes the list of tasks and the estimated timeframe required to start and complete the objectives. The 3 main topics highlighted in red are Literature Review, Simulation Phase and Technical Phase which are pre-defined earlier under proposed approach in chapter 1. ENG499 CAPSTONE PROJECT REPORT 7 Chart 1.2 Gantt chart 1.5.3 Required Resources The following table list down the resources used to complete this project. PROJECT RESOURCE Reference books and related journal papers Agilent ADS software for modelling and simulation AVAILABILITY SIM Library, National Library, Internet Evaluation version is available at Agilent website (License renewable every 3 months) Web URL : http://www.home.agilent.com/agilent/download.jspx ?nid=-34346.0&cc=US&lc=eng&pageMode=DL Network Analyzer Available in SIM laboratory (300KHz – 300GHz) Spectrum Analyzer Available in SIM laboratory (9KHz – 3GHz) (Optional) Signal Generator (9KHz Available in SIM laboratory – 3GHz) (Optional) Table 1.2 Resources used for this project ENG499 CAPSTONE PROJECT REPORT 8 CHAPTER 2: REVIEW OF THEORY AND PREVIOUS WORK 2.1 Literature Review on LTCC Technology 2.1.1 Definition of LTCC Low Temperature Co-fired Ceramic (LTCC) can be defined as glass-ceramic compound suitable for integrating inductors, capacitors and resonant components into multilayer structures. In today’s industry, there is high demand for technology to realize complex integrated circuits into multilayer structures. Passive components such as resistors, inductors and capacitors are usually soldered and surface-mounted onto their terminals on a printed circuit board. This conventional way is phasing out to Embedded Passive Technology (EPT) which enables the passive components to be embedded into inner layers. Some of the benefits from using EPT include, i. ii. iii. iv. v. Higher reliability Reduced circuit size due to embedded components Higher propagation speed signals Better immunity to electromagnetic interference Reduction in manufacturing cost ENG499 CAPSTONE PROJECT REPORT 9 Figure 2.1 Embedded passive elements Due to these properties, LTCC substrates offer higher volume, lower cost and compact sizing for various microwave applications. They are manufactured by stacking up laminating green sheets also known as “Green Tape” in layers on top of each other in parallel before co-firing them together. The process of LTCC is similar to HTCC process but one benefit is the possible usage of low resistivity conductors like gold, silver and alloys with palladium and platinum instead of tungsten and molybdenum due to its low firing temperature. These two technologies are also categorized based on the firing temperature range. For LTCC (In general 850 - 870 °C, T ≤ 1000 °C) For HTCC (Above 1000 °C, T ≥ 1500 °C) However, LTCC technology is not totally flawless. Low thermal conductivity of the ceramic tape, materials and fabrication processes in the past has greatly limit power and radio frequency application to lower GHz range. One way to help rectify this problem is by implementing thermal vias to increase the conductivity of the substrate. [1][2] Figure 2.2 LTCC Diagram 2.1.2 Benefits of LTCC This section lists down the benefits of using LTCC technology. i. ii. LTCC economize manufacturing time with its parallel processing capabilities Mass production is possible with LTCC due to its ability to automate several process steps at a time ENG499 CAPSTONE PROJECT REPORT 10 iii. iv. v. vi. vii. viii. ix. x. xi. xii. xiii. xiv. xv. LTCC offers ease of fabrication with automatic package device functions thus reducing overall production cost Tapes of different composition can be produced with desired layer properties LTCC technology allows modification of thermo-physical properties Able to integrate electronic circuits due to its hybrid properties Offers Three-Dimensional (3-D) integration capabilities Easy to cut and customize into different shapes and sizes Greatly reduce the circuit size up to 50% by embedding passive components within the substrate Able to contain large number of signal layers Able to work at frequencies of 30GHz or higher High temperature resistance makes it suitable as a material even in harsh ambient conditions (Up to 350 °C) Higher thermal conductivity then general PCBs Able to work with equipment using thick film conventional technology Can be used together with conductive materials like gold and silver due to its excellent electrical properties [1][2] 2.1.3 LTCC Process ENG499 CAPSTONE PROJECT REPORT 11 Figure 2.3 LTCC Process In this section, different ways of processing LTCC are studied. It is similar to HTCC with lesser steps and complications. Production and Cutting of Green Sheets: The green sheets mainly come in a single row and have to be unrolled onto a clean table to be cut up and processed. Laser power is carefully controlled during slitting to avoid accidental firing of the sheet. Some tapes like Dupont Green Tape require pre conditioning. The Green sheet has to be baked for 30 minutes at approximately 120 °C based on material and manufacturing properties. Orientation marks and lamination holes are created using blanking dies. Vias may be formed by punching or drilling using low powered laser. ENG499 CAPSTONE PROJECT REPORT 12 Figure 2.4 Cutting or Slitting of green sheets Via Punching and Filling: After pre processing, via holes and cavity openings are mechanically punched. Via filling process has limited options. It works by filling up vias thru thick film screen printer. Another way is to fill the vias using a special extrusion via filler under working pressures of around 4-4.5 bars. A mask is required both ways. It is advisable to create the holes concerned of the mask lesser then the blind vias diameter to prevent filling rate errors. This method is known as the Screen Printing Technique. Figure 2.5 Via Punching and Filling Printing: Co-fireable conductors are printed on the sheet using a conventional thick screen printer. The screen size is fixed at 250 – 325 emulsion type. Similar to via printing operations, a porus stone assist in holding the tape in position. The vias and conductors are placed into the oven for drying after printing. Stacking: The alignment process stack up multiple layers together based on vias and wiring. Precautions should be taken to ensure the green glass ceramic do not make direct contact with the alignment device during this stage. Figure 2.6 Alignment device a) Plan view b) Side view c) Perspective view ENG499 CAPSTONE PROJECT REPORT 13 There are two methods of laminating the tapes. Uniaxial lamination: The tapes are pressed in the middle of heated platens under temperatures of around 70 °C for roughly 10 minutes under 200 bar pressure. The tapes have to be rotated 5 minutes later. This method is known to create high shrinkage issues. Isostatic lamination: The tapes are stacked up and vacuum packed in a coil and pressed in hot water under 350 bar pressure. Temperature conditions are similar to Uniaxial lamination mentioned above. Co-firing: The laminates are fired in a single step smooth flat surfaced tile. It is important to follow a fixed firing profile which requires a programmable box kiln. Standard profiles have conditions of rising temperature at steady 2-5 °C pace per 60 seconds up till 450 °C. The dwell time is estimated to be 1-2 hours. If organic burnout occurs, the temperature is to be raised between 850 °C and 875 °C with 15 minutes timeframe. Material properties such as size and thickness will affect the duration of co-firing which usually lasts 3-8 hours. Figure 2.7 Co-firing process Post-firing: It is necessary to post-fire certain materials. This means the paste is to be applied after firing the tape and re-fired once more. Post-firing condition depends on the material used. Singulation: Some fired parts need to cut up into different shapes and sizes. We can perform these by using a post fire dicing saw, ultrasonic cutter or laser. [1][2][3] 2.1.4 LTCC Applications LTCC is widely recognized as one of the leading multi-layer technologies for the past decade and is critical in many applications today. They are used to produce Multichip Ceramic Modules (MCM-C) meant for packing integrated circuits and various microwave device. Many sensors and actuators also utilize LTCC due to their excellent electrical and mechanical properties. LTCC technology is also well established in military and space environments for low volume, high performance applications (Transmitters, Receivers, and Radars etc). We can also find them in filters, mobile phones and many other wireless applications. The uses of LTCC in Automobile Industry are also wide. Gearbox and engine in an automobile vehicle also ENG499 CAPSTONE PROJECT REPORT 14 makes use of LTCC in the process, as well as anti lock brakes, Global Positioning System (GPS) and many more. [4] Table 2.1 below show some common LTCC applications for various frequency bands. S/NO 1 Application Dual-band power amplifier Frequency 900 – 1800 MHz 2 Bluetooth module with integrated antenna 2.45 GHz 3 Multiplier 8 – 24 GHz 4 Band pass filter 24.5 – 25.5 GHz 5 Point to point transceiver module 27.5 – 29.5 GHz 6 Transitions from panar to rectangular waveguide 30 – 35 GHz Photo Table 2.1 LTCC applications ENG499 CAPSTONE PROJECT REPORT 15 2.2 Literature Review on Microstrip Technology Microstrips can be referred as electrical transmission lines used on Printed Circuit Board (PCB) technology meant for transmitting microwave frequency signals. The architecture consists of conducting strip separated from ground plane on dielectric substrate material. It can be used as replacement for microwave components such filters, antennas and power dividers, greatly reducing circuit space and cost. 2.2.1 Microstrip Structure Microstrip architecture comprises of three layers. The first layer is usually conducting strip having width W, thickness t. The second layer below the conducting strip lays substrate material with relative dielectric constant r and thickness h. The last and bottom layer of the substrate is usually ground (conducting) plane. The width W and thickness t of the conducting strip affects characteristic impedance and frequency. Making use of microstrip lines can be beneficial in many ways. Such as more compact sizing and the ease of integration with other microwave components. [5] Figure 2.8 Structure of Microstrip 2.2.2 Wave in Microstrip We can refer to microstrips as inhomogeneous structure as fields in microstrip extend towards free space above and dielectric substrate below. As a result, pure TEM waves are not supported. Pure TEM waves only consist of transverse components, and its propagation velocity depends much on the permittivity and permeability of the material. This situation can change with the introduction of two guided-wave media (air and dielectric substrate). The waves in microstrip lines will have no vanished longitudinal components of electric and magnetic fields, thus the propagation velocities will depend on not only material properties, but also on the microstrip physical properties. [5] ENG499 CAPSTONE PROJECT REPORT 16 2.2.3 Effective Dielectric Constant and Characteristic Impedance The Quasi-TEM mode occurs when longitudinal components averages less then transverse components and is valid for most microstrip operating frequencies range. Two important characteristics of microstrip in transmission can be identified as: Effective dielectric constant, re Characteristic Impedance, Z c Based on the above characteristics and quasistatic analysis, we can define the following capacitance value stated below, where Cd is the capacitance per unit length based in present dielectric substrate, and Ca is per unit length with free space, whereby velocity of wave in free space is c 3.0 x108 m / s . [5] re Cd Ca (1) Zc 1 c Ca Cd For narrower microstrips, where r 1 r 1 W 1 , we have, h h re 1 12 2 2 W 0.5 Zc 2 re (2) W 8h In 0.25 h W For wider microstrips, where W 1 , we have, h re r 1 r 1112 h 2 2 W 0.04 1 h 2 0.5 (3) W W W Zc h 1.393 0.677 In h 1.444 re 1 Based on the above expressions, the characteristic impedance in free space Z0 : Z0 0 120 , with: 0 ENG499 CAPSTONE PROJECT REPORT (4) 17 0 : Vacuum permeability 0 : Vacuum permittivity 2.2.4 Guided Wavelength The guided wavelength from quasi-TEM mode of microstrip can be derived once we determine the effective dielectric constant. [5] g 0 re (5) Where 0 equates to free space of wavelength at operating or center frequency f. It is also necessary to derive the electrical length once values for physical length l have been calculated. l (6) 2 With the guided wavelength value, physical length of the microstrip can be found using the below equations. For half wavelength, l g (7) 2 For quarter wavelength, l g (8) 4 2.2.5 Synthesis of W/h A common problem faced by engineers designing microwave circuits is to determine the width of microstrip and getting the desired impedance. The follow equations help to calculate the synthesis effectively. [5] For W 2, h W 1 4 exp( A) exp( A) h 2 ENG499 CAPSTONE PROJECT REPORT 1 (9) 18 With, A For Zc Z0 2( r 1) r 1 0.11 0.23 r 1 r W 2, h W r 1 0.61 2 B 1 Log (2 B 1) L og exp( B 1) 0.39 h r r With, B (10) Z0 2 r Zc 2.2.6 Coupled Lines It is common for microstrip filters designers to make use of coupled microstrip lines technology. A pair of microstrip lines of width W placed in parallel, also described as edge-coupled configuration separates each other by a line gap s. This method enables support for two quasi-TEM modes, which is the even and odd mode. Both microstrip lines carry equal charges and voltage potentials in even mode which produces a magnetic wall at the symmetry plane. The process is the reverse in odd mode, with strip lines carrying opposing potential and charges. Both modes can be excited simultaneously, but vary in phase velocity and permittivity. To summarize, both modes can be classified based on impedance properties and dielectric constants. [6][7] Figure 2.9 Cross sectional view of coupled microstrip lines 2.2.7 Even and Odd mode Capacitance The properties of even and odd mode impedance and actual dielectric constants of the paired coupled microstrips can be defined in a similar fashion to a lone microstrip represented by Ce and Co . [6] The even and odd mode capacitance can be defined from the below mention equations, Ce C p C f C f , Co C p C f Cgd Cga ENG499 CAPSTONE PROJECT REPORT 19 From the above equations, C p represents the plate parallel capacitance in middle of strip and ground plane. It can be derived as, C p o rW / h The fringe capacitance can be denoted as C f , and based on a single microstrip, can be derived as, 2C f re /(cZ c ) C p The modification of C f due to other microstrip lines is C f , , Cf , Cf 1 A(h / s) tanh(8s / h) , A exp 0.1exp(2.33 2.53W / h In regards to the odd-mode, C gd and Cga , denotes the fringe capacitance for air and dielectric area across the coupling gap. The capacitance C gd may be located from corresponding coupling strip lines, with spacing given as 2h. Thus, it can be expressed as, Cgd 0.02 r o r s 1 ln c | oth( ) 0.65C f ( 1 2 ) 4h s/h r We can modify the capacitance Cga using the corresponding coplanar strips capacitance value. It can be express as, Cga o s/h K (k ' ) , k ' 1 k 2 , where k s / h 2W / h K (k ) Figure 2.10 Quasi-TEM modes of microstrip pair: (a) even mode; (b) odd mode ENG499 CAPSTONE PROJECT REPORT 20 2.3 Literature Review on RF Filter Design and Methodology 2.3.1 Definition of RF Filter Radio Frequency (RF) filters can be defined as electronic filter type. The main purpose is to filter signals from wireless transmission under medium to high frequency range (MHz to GHz) supporting various applications such as Radio, TV broadcast, mobile phones and broadband internet (Wi-Fi). There are widely used as building blocks for diplexers to combine and separate multiple frequency bands. In general, pass band signals are signals which are allowed by the filter to pass thru. This band of frequencies often occur below the filter cut off frequency which falls ENG499 CAPSTONE PROJECT REPORT 21 50% (-3dB) of the in band level, assuming a fixed input level. A band of frequencies rejected is defined as the stop band. It is taken as the starting point where the rejection level occurs. To be realistic, it is not possible to obtain a perfect pass filter as some loss will definitely occur within the pass band. Infinite rejection in the stop band is also unattainable. Note that transition will always occur between the pass band and stop band. When the response curve drops, the rejection level will increase as frequency travels from the pass band to stop band. To summarize, the use of RF filters for controlling acceptance or rejection of frequency signals makes it valuable for RF engineers. [8][9] 2.3.2 RF Filter Types There are four main types of filter with different properties of its own. Each filter has its unique way of accepting or rejecting signal. By applying the relevant filter type, one can customized how signals are being accepted or rejected. The four types of RF filter are mainly: i. ii. iii. iv. Low pass filter High pass filter Band pass filter Band reject filter Band-pass filters: Works by allowing certain frequencies within a range and attenuates outside the range. The RLC circuit can also be suggested as a type of analogue band-pass filter. An alternate way to achieve band-pass effect is by combining low-pass filter with a high-pass filter. Band-stop filter: Otherwise known as the band-rejection filter, it does not alter any frequency signals but attenuates specific stated ranges to extreme low levels. It works directly opposite to the band-pass filter. The capability to reduce feedback without affecting much of the frequency spectrum means they can be implemented in live sound reproduction systems such as audio instruments amplifier and PA systems. High-pass filter: Allows high frequency signals and attenuates frequencies below the cut-off frequency range. Low-pass filter: The direct opposite of the high-pass filter. It only passes low frequency signals and attenuates signals with frequencies above the cut off frequency. Frequency attenuations can be inconsistent and depends on various filter conditions. For audio purposes, the filter is also known as the treble-cut filter or high-cut filter. They help to smoother the signals and reduce short-term fluctuations. [8][9][10] ENG499 CAPSTONE PROJECT REPORT 22 Figure 2.11 Types of RF filter 2.3.3 Filter Classification The uses for filters are vast. Different results can be obtained from modifying basic filter structures to meet different criteria. For example, in band ripple circuits, the fastest transition to the ultimate roll off, and the highest out of band rejection are criteria for different circuit values. By optimizing these values, we can obtain filters with different performance. Butterworth filters contribute maximum in band flatness and rolls off towards zero in the stop-band. Its characteristics show monotonic ripples in the pass-band or stopband. Chebyshev filters provide the fastest roll off once the cut off frequency has been reached. They help to minimize error rate between the idealized and actual filter characteristic over the range of the filter, but with ripples in the band pass. Bessel filters has the best step response, providing optimum in-band phase response. Elliptical filters contains huge in band and out band ripple. As the degree of ripple tolerance increases, the rate to ultimate roll-off also increases. ENG499 CAPSTONE PROJECT REPORT 23 Figure 2.12 Comparison of various filter response Generally, RF filter design above the 500MHz range can be hard to implement using discrete components due to wavelength complications affecting the filter performance. To overcome this, it is necessary to convert lump component filters into distributed elements form. For example, the Richards designed transformation tool that allows open and shortcircuit transmission line segments to emulate inductive and capacitive properties of discrete components. It is also crucial to convert an originally complex filter design to a more suitable realization form. For instance, it is easier to implement a shunt stud line as compared to implementing series inductance using short-circuit transmission line segment. We can use Kuroda’s identities to ease the conversion process. [8][11] 2.3.4 Edge-Coupled Bandpass Filter Edge-coupled bandpass filters are constructed in a way whereby the adjacent resonators are parallel to each other along half of their length. This arrangement allows for larger coupling between resonators in a given space area. They are suitable for wide band applications but one downside is radiation which can be overcome by shielding. ENG499 CAPSTONE PROJECT REPORT 24 Figure 2.13 Edge-Coupled Half Wavelength Resonator Filter Parameters are formed from the admittance inverter ( J jj 1 ) thru the quarter wave transformer. For the first coupling structure, J 01 FBW Y0 2 g0 g1 (11) For subsequent coupling structures, J jj 1 Y0 FBW 2 1 , j 1 to n 1 g j g j 1 (12) For the last coupling structure, J n,n 1 Y0 FBW 2 g n g n 1 (13) Where g0 , g1...gn comprises the element of a ladder-type low-pass prototype with normalized cut-off c 1 and FBW makes up the fractional bandwidth of the filter. J jj 1 defines J-inverters characteristic admittance and Y0 termination defines line characteristic admittance. To calculate J-inverters from the above equations, the odd and even mode characteristic impedances of the coupled microstrip line resonators can be derived by the following equations. The value g refers to prototype elements. 1 The characteristics admittance Y0 = whereby Z 0 = 50 in general cases. Z0 ENG499 CAPSTONE PROJECT REPORT 25 2 1 ) for 2 and 0 1 are the high and low cut-off frequency and 0 is the center frequency. FBW or ( ) can be defined as the standardized bandwidth ( At any point of time, relative polarity of voltages along a direct coupling structure can be similar or opposite to each other. We can refer to this opposing phenomenon as the “even mode” and “odd mode’. The equations for characteristics impedance of the odd and even modes are stated next: For even mode, 2 1 J j , j 1 J j , j 1 ( Z 0e ) j , j 1 1 j 0 to n Y0 Y0 Y 0 (14) For odd mode, 2 1 J j , j 1 J j , j 1 ( Z 0o ) j , j 1 1 j 0 to n Y0 Y0 Y0 (15) Once the values Z 0e and Z0o are calculated, using equations defined earlier in sections 2.2.4, the length, width and gap of the coupling region can be determined. The length of coupling region: l' j gj 4 2d (16) Considering d jj 1 remains constant throughout and offset value d = 0.165 x h where h is the substrate material thickness. Table 2.2 shows the element values of Chebyshev band-pass prototype with 0.1 –dB ripple. [12] Table 2.2 Element values for Chebyshev prototype filter ( g0 1.0, c 1) ENG499 CAPSTONE PROJECT REPORT 26 2.3.5 End-Coupled Bandpass Filter The end-coupled bandpass filter has open-end microstrip resonators roughly half wavelength long towards the center frequency. Coupling is generated from gaps between two adjacent ends, thus it is also known otherwise as the gap-coupled filter. In such cases, the gaps can be compared to inverters which reflect high impedance level at the end of each half wavelength coupling resonator. This causes the resonators to exhibit shunt-resonator properties. [12] Figure 2.14 End-Coupled Bandpass Filter 2.3.6 Hairpin Line Bandpass Filter Hairpin-line bandpass filters are compact in size due to their unique design which consists of folded half wavelength, parallel-coupled resonators forming a distinct “U” shape. This concept is otherwise known as the hairpin resonator. To achieve proper coupling, it is necessary to control the coupled-line lengths and make sure the two arms of each hairpin structure have ample spacing between them. [12] Figure 2.15 Hairpin-Line Bandpass Filter ENG499 CAPSTONE PROJECT REPORT 27 2.3.7 Interdigital Bandpass Filter Interdigital bandpass filters are widely common in microstrip design circuits. The structure is generally built from arrays of quasi-TEM-mode line resonators. The electrical length is about 90 degrees towards the center frequency. Each adjacent microstrip has one end open-circuited and the other end short-circuit in an alternating pattern. To summarize, the physical dimensions of the filter varies and is not consistent throughout depending on the coupling required. The filter input transmission lines are tapped and impedance is altered to match the source/load characteristic admittance. [12] Figure 2.16 Interdigital bandpass filter ENG499 CAPSTONE PROJECT REPORT 28 2.4 Network Analysis and Scattering Parameters Filter networks form critical portions in numerous RF/Microwave applications. Microwave equipments should be able to accept/reject or mix/split different range of frequencies. The ways of constructing the filter topologies might vary, but the concept of network topology remains constant. Figure 2.17 Two port network with variables Scattering parameters also known as S-Parameters can be represented as wave components. S11 b1 Reflection power at Port 1 |a2 0 , a1 Incident power at Port 1 S12 b1 Transmission power at Port 1 |a1 0 , a2 Incident power at Port 2 S 21 b2 Transmission power at Port 2 |a2 0 , a1 Incident power at Port 1 S 22 b2 Reflection power at Port 2 |a1 0 , a2 Incident power at Port 2 It can be noted that S11 and S 22 are reflection co-efficient while S12 and S 21 are transmission co-efficient and an 0 indicates zero reflection from the terminal impedance at port n. Certain advantages of S parameters can be helpful in analyzing networks. Such as for reciprocal networks, we can assume that S12 S21 . For identical networks in symmetric, S11 S22 , meaning symmetrisation also reciprocates. A ideal filter response should have the reflection co-efficient S11 and S 22 better or lesser then -10dB and transmission co-efficient S12 and S 21 to be as close as possible to 0, meaning to achieve a flat S 21 response. [13] ENG499 CAPSTONE PROJECT REPORT 29 Figure 2.18 Typical bandpass filter response 2.5 Advanced Design System (ADS) Agilent Advanced Design System (ADS) is currently one of the best electronic design and automation software used for RF, microwave and signal integration applications. ADS have successfully pioneered leading innovation and commercial technologies like X-parameters*, Momentum and 3-D EM simulators which are highly adopted by major companies in the following industries (Aerospace, Wireless communication and Networking and Defence). ADS’s integrated platform provide circuit-system-EM-cosimulation, standard full based design and verification with wireless libraries for applications such as WiMAX, LTE, multi-gigabit per second data links, radar and satellite related applications. With ADS, engineers can enjoy the convenience of preparing schematic drawings, layouts and simulation without the need for installing multiple software system. Some key features of ADS include: i. ii. iii. Harmonic Balance: Enable analysis for non-linear circuits excited with multitone source and preset simulation for RF, microwave and various circuit design Circuit Envelope: To assist in simulation for digitally modulated RF signals. Also contains templates for RF systems design. Momentum G2: 3-D planar electromagnetic (EM) simulator used for analyzing passive circuits. [14] ENG499 CAPSTONE PROJECT REPORT 30 2.6 Printed Circuit Board Finishing Techniques It is necessary to ensure good finishing between the components and circuit board interface to protect the exposed copper threads and preserve solderability so as to minimize failure rate. In this section, we explore some common ways of employing finishing to PCBs. [15] 2.6.1 Hot Air Solder Level (HASL or HAL) HASL works by immersing PCB into molten solder. For most application involved, the solder alloy used is tin-lead. The surface tension of molten solder contributes to HASL texture and thickness which is between 2 to 20um. HASL provide excellent shelf life and offers ample solderability resistance but tend to leave high levels of residues after fluxing. HASL promotes flexibility and can be used in both horizontal and vertical equipment. The fabrication process steps are listed below: i. ii. iii. iv. Copper is pre-treated by cleaning then micro etched and fluxed Panels are dipped into molten solder after pre-treatment Blowing off excess solder using air knifes Rinsing away excessive flux residues HASL Advantages i. Cheap compared to other finishes ii. Copper/Tin solder joint iii. Easily available iv. Able to be reworked on HASL Disadvantages i. Not flat ii. Paste misprints iii. Below average fine-print assembly iv. Thick intermetallics v. May contain Pb (Lead exposure) vi. May cost thermal damage to PCB Table 2.3 Advantages and Disadvantages of HASL finishing 2.6.2 Organic Solderability Preservative (OSP) OSP consist of mini organic coatings utilized for preserving solder compounds on PCB copper thread. Most of its attributes limit to purely solderability as compared to other finishing. OSP consists of chemicals used in anti-tarnish coating such as Benzimidazoles and Phenylimidazoles which have lasting effect on multiple soldering operations. The cheap price of OSP coating makes it widely popular in the industry. However, OSP uses are limited due to poor contact properties and can also degrade after multiple thermal application. OSP copper complex readily deposits on the board surface up to thickness of 0.10 to 0.60um. ENG499 CAPSTONE PROJECT REPORT 31 Figure 2.19 OSP molecule types Process Cleaner Microtech Pre-dip OSP Chemicals Aqueous solvents, detergents and emulsifiers. To remove undercut residues using acidic solutions 1-2um of copper is oxidized to Cu++ and dissolved The usual method in which predip uses ingredients of the OSP bath without using the chemical itself OSP, acetic or formic acid, source of copper and other metallic materials Table 2.4 OSP process flow Time (min) 1.0-4.0 1.0 0.5 0.5-1.0 Table 2.5 illustrate the advantages and disadvantages of using OSP coating. OSP Advantages i. Flat, fine-pitch assembly ii. Least expensive of all coatings iii. Simple process iv. Easily available v. Copper/Tin solderjoint vi. No Lead vii. Easy to rework on viii. High fabrication productivity OSP Disadvantages i. Not direct to measure thickness ii. Not easy to apply on contact surface iii. Poor PTH soldering iv. Short shelf-life v. Exposure of copper on final assembly vi. Unable to be checked before completion of assembly vii. Quality degrades over multiple reflows viii. Sensitive to handling ix. Issues with paste misprint cleaning Table 2.5 Advantages and Disadvantages of OSP finishing ENG499 CAPSTONE PROJECT REPORT 32 2.7 FR4 Substrate FR4 have been widely utilized in printed circuit manufacturing industry for many years. They consists of mainly epoxy-based materials For use on less complex applications, the choice would be to select materials with thermal conditions of 130 to 140 degree Celsius Tg . For multilayer applications, materials with higher thermal point of 170 to 180 degree Celsius Tg should be used. To add on, material such as woven fibreglass cloth and epoxy resins provide good combination of performance, possibility and cost. With a wide range of cloth styles available, it is easier to control circuit thickness and dielectric properties. The epoxy based type materials also make it more manageable to cut or customize based on requirements. Based on the above advantages, FR4 continue to provide reliable performance, easy processing and cost effectiveness in the printed circuit industry. [16] Figure 2.20 Copper clad laminate FR-4 2.8 Network Analyzer The RF network analyzer measure electrical and network parameters for various components ranging from filters, mixers, transistors and other RF oriented devices. We can also observe behaviours of the RF circuit by measuring the response. Scalar network analyzer (SNA): This analyzer can be used only for amplitude properties measurement. It basically works like a spectrum analyzer with a tracking generator on the DUT. Vector network analyzer (VNA): The VNA also called the gain-phase meter or Automatic Network Analyzer, measuring the amplitude and phase properties of the device tested. It is much powerful compared to SNA and has a wider set of functions ENG499 CAPSTONE PROJECT REPORT 33 which includes analyzing amplitude response, networking scattering parameters, sparameters, which are the transmission and reflection co-efficient. Large Signal Network Analyzer (LSNA): LSNA is a powerful and highly specialised analyzer used to provide details of harmonics, and non linearity of a network under large signal conditions. Another naming for this device is Microwave Transition Analyzer (MTA). The network analyzer consists of the following sections: RF network analyzer stimulus / source: The analyzer is an active test platform which generates signal to the device under testing, and measure the response from it. The stimulus or source in this case works like the signal generator. It has two modes to sweep power and frequency. Signal Separation: The signal separation element measures part of the incident signal to provide reference point known as “rationing”. It can also separate the incident and reflected travelling waves at the DUT input. Receiver and signal detection: The receiver which can be in the form of a simple diode detector works like demodulator to separate the source signal from the test object. Processor and display: The processor outputs the processed signal from the receiver thru display in the form of plots and smith charts. [17][18] Figure 2.21 Large Signal Network Analyzer (LSNA) ENG499 CAPSTONE PROJECT REPORT 34 CHAPTER 3: PROJECT SELECTIONS 3.1 Selection of Substrate Material The low-temperature co-fired ceramic (LTCC) is a multilayer substrate produce from combining several layers of material and mostly consist of several materials such as alumina dust, glass compounds, organic binders, solvents, dispersing elements with the main material as alumina. For the C-Band filter operating at 5.3GHz, LTCC substrate with dielectric constant of 10, thickness of 635um was chosen. For the Ka-Band filter operating at 28GHz, LTCC substrate with dielectric constant of 7.84, thickness of 100um was chosen. For the improvised design, FR4 substrate with dielectric constant of 4.7, thickness of 1600um was chosen for fabrication to match budget allocated budget and available school equipment. 3.2 Selection of Filter Methodology The project requirement is to design an edge-coupled wide bandpass filter suitable for MCM applications. Edge-coupled filter generally consist of stripline arrays quarter wavelength long. One end of the resonator is open-circuited while the other end is close-circuited in alternating pattern. Such a design makes the filter compact since all striplines are utilized as resonators. Based on microstrip characteristics, increasing the substrate height reduces coupling effects. In general, to design filters performing at 15% bandwidth can be relatively achievable. However, for wider bandwidths (C and Ka-Band) requirement, it is necessary to have coupling lines with very narrow gaps which posed an issue to implement due to manufacturing limitations. The LTCC MCM method rectifies this issue. Adopting this technique allows for line width and gaps spacing to be as little as 15pm, definitely not attainable using conventional thick-film approach. 3.3 Selection of Software Modelling and Simulation tools are essential built-ups of a project design. The engineer can perform pre-test analysis and evaluate if the design is workable before proceeding to manufacture the actual product. Three RF designing software were considered for this project. i. Agilent Advance Design System ENG499 CAPSTONE PROJECT REPORT 35 ii. iii. AWR Microwave Office Ansoft HFSS Table 3.1 shows a comparison of the features available for each of the above mentioned software programs. Properties ADS HFSS MWO User Friendliness Hard Average Easy Online help and Available Available Available support features Support Simulation Yes Yes Yes Support SYes Yes Yes Parameters 3D EM visual Yes Yes Yes capabilities Resource High Average Low consumption Price Free trial Free trial High Table 3.1 Comparison of software features Based on the above comparison, ADS offers the best options due to its user friendly platform, comprehensive templates and tutorial guides. Free trial for ADS is also available and system requirements are minimal which help to speed up simulation time required. Thus, ADS have been chosen as the software for this project. [19][20] 3.4 Selection of PCB Finishing There are various types of PCB finishing available in the market today. To help determine the correct finish to apply, the list below gathers information on what each type of finish offer in terms of reliability, solderability, and cost factor. [21] Properties Lead free compatibility based on RoHS compliant Solder joint reliability Shelf life Assembly heat cycles Ability to withstand thermal shock during fabrication Ease of solder flow onto surface Solder paste IAg Yes ENIG Yes OSP Yes ISn Yes HASL No Very good Good Good Good Excellent Good Multiple Good Multiple Good Multiple Good Multiple Good Multiple Excellent Good Good Good Poor Very Good Excellent Good Good Good Excellent Excellent Excellent Excellent Poor ENG499 CAPSTONE PROJECT REPORT 36 printability for fine pitch device Low Yes Depend on Yes Yes contamination Au % possibility Low contact Good Good Poor Good resistance Aluminium wire Good Good Poor Poor bonding Price Average High Average Low IAg – Immersion Silver ENIG – Electroless Ni/Imm Au OSP – Organic Solderability Preservative ISn – Immersion Tin HASL – Hot Air Solder Levelling Table 3.2 Comparison of different PCB finishing No Poor Poor Low 3.5 Selection of Measuring Equipment Once fabrication process is completed, prototype measurements can be taken. The Agilent Network Analyzer Model E5062A is available in SIM University laboratory and caters for generic S-Parameters measurements. [22] The following shows specifications on the equipment. i. ii. iii. iv. v. vi. vii. 300KHz to 3GHz Integration of T/R Testing set for S-Parameter Testing port is available in 50 or 75 ohms Dynamic range value of 120dB Trace noise of 0.005dB In-built Visual Basic capabilities Figure 3.1 Agilent E5062A Network Analyzer ENG499 CAPSTONE PROJECT REPORT 37 3.6 Selection of SMA Connector The Sub Miniature Version A (SMA) connector is a type of coaxial connector meant for RF use. Typical uses for SMA connectors include cable box, modems and TV signal connectors. For this project, 50ohm SMA connectors that provide excellent electrical performance from DC to 18GHz range are chosen. The SMA connectors are compact in sizing and provide excellent durability. The SMA connectors also come in various mounting types to help minimize mechanical adjustments. Based on the proposed filter design, the 2-hole flanged SMA (Manufacture Part #1420701-621) connector was chosen as it best fitted the design without the need for further modification which may damaged the fabricated PCB if mishandling occurs. However, extra care should be taken when soldering the connector to make sure ground points are well soldered to the flange holes and also to prevent contact with the signal pin. The SMA connector can be purchased from Sim Lim Tower at about $5 each. [23][24] Figure 3.2 Two-holed flanged SMA connector jack Figure 3.3 Different types of SMA connectors ENG499 CAPSTONE PROJECT REPORT 38 CHAPTER 4: FILTER DESIGN USING LTCC The initial design is based on 7th order Chebyshev bandpass filter operating at a center frequency of 5.3GHz and 28GHz respectively. Seven resonators using edge-coupled methodology were implemented on LTCC substrate. The first and seventh resonators were place on the top LTCC layer; remaining resonators were placed on the second LTCC layer so as to optimize capacitive value as a trade off between the insertion losses and to narrow bandwidth properties. The bottom layer is the ground plane. The input lines are set with 50 ohms impedance and connected on top surface of the LTCC substrate. (a) (b) Figure 4.1 LTCC bandpass filter (a) Schematic view, (b) 3-D view 4.1 Design of C-Band Filter using LTCC This filter was designed to operate at center frequency of 5.3GHz. The first step will be to setup substrate layers and simulation parameters in ADS. ENG499 CAPSTONE PROJECT REPORT 39 4.1.1 ADS Setup for C-Band Filter For ADS setup, we need to define substrate layer properties and setup s-parameters. The dielectric constant of LTCC substrate was defined as r 10 with 635 m height. The test frequency range will be from 4GHz to 7GHz. Sample points were set at 999. (a) (b) (c) Figure 4.2 (a) Substrate layer (b) Layout layers (c) S-Parameters settings for 5.3GHz filter 4.1.2 Dimensions of C-Band Filter The initial filter dimensions can be calculated using equations listed in Chapter 2.2.4 and also using ADS LineCalc function. First, we calculate the dimension of input lines. They are configured to provide 50 impedance to match the SMA connectors. Dielectric constant r = 10 Substrate Thickness h = 635um Conductor Thickness t = 17um Characteristic impedance, Z 0 = 50 Using LineCalc, we determine the length and width of the input lines. ENG499 CAPSTONE PROJECT REPORT 40 Figure 4.3 LineCalc for input lines (C-Band) To demonstrate the accuracy of LineCalc, manual calculation was performed as listed below. re r 1 r 1 2 h 1 12 2 W 10 1 10 1 h 1 12 2 2 W 6.906 0.5 0.5 W W Zc h 1.393 0.677 In h 1.444 re 1 120 587.018 587.018 635 1.393 0.677 In 635 1.444 6.906 50 ENG499 CAPSTONE PROJECT REPORT 1 41 Setting of single 50ohm port in ADS is shown below. Figure 4.4 Setting of single mode 50ohms port (C-Band) Specifications of the filter design with central frequency of 5.3GHz, low cut-off frequency of 4.9GHz and high cut-off 5.3GHz. Step 1: Normalized Bandwidth, 2 1 5.7 4.9 0.151 0 5.3 Step 2: Next, the parameters for the 7 coupling structures are calculated using Equations (11), (12), (13). j 1 0.448 J j , j 1 2 0.183 3 0.137 4 0.13 5 0.137 6 0.183 7 0.448 Y0 Step 3: Followed by the even and odd impedances, j ( Z 0 e ) j , j 1 () 1 82.44 2 60.82 3 57.79 4 57.35 5 57.79 6 60.82 7 82.44 ( Z 0 o ) j , j 1 () 37.64 42.52 44.09 44.35 44.09 42.52 37.64 ENG499 CAPSTONE PROJECT REPORT 42 Step 4: From the ( Z0e ), ( Z0o ) values, we can evaluate line length l, width W and line gap/spacing S values using LineCalc. j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 344 526 547 550 547 526 344 177 524 699 734 699 524 177 l ' j ( m) 5736 5528 5499 5495 5499 5528 5736 Figure 4.5 LineCalc for coupling lines (C-Band) For guided wavelength, g 0 ( f ) re 3 x108 (5.3 x109 ) 6.906 21539.33 m Using equation (16), length of each coupling structure is roughly: l' j gj 2d 4 21539.33 m 2(104.8 m) 4 5175 m ENG499 CAPSTONE PROJECT REPORT 43 Considering d jj 1 remains constant throughout and offset value d = 0.165 x h where h is the substrate material thickness 635 m . 4.1.3 Initial Design for C-Band Filter The initial design and simulation results are obtained from above steps. Center Frequency: 4.09GHz Bandwidth: 899MHz Insertion Loss (IL): -0.014dB Return Loss (RL): -2.468dB We are looking to achieve center frequency of around 5.3GHz, low and high cut-off frequency at 4.9GHz and 5.7GHz respectively. S21 response is also not flat. The overall results are not satisfactory. Seven coupled line with different lengths ( m ) L1,L7=5736 L2,L6=5528 L3,L5=5499 L4=5495 W1,W7=344 Seven coupled line with different widths ( m ) W2,W6=526 W3,W5=547 W4=550 S1,S7=177 Seven coupled line with different spacing ( m ) S2,S6=524 S3,S5=699 S4=734 50686x8004x1270 Overall Dimension ( m ) Table 4.1 Initial dimensions for C-Band filter m2 freq=4.221GHz dB(S(2,1))=-3.659 m1 freq=3.774GHz dB(S(1,1))=-3.186 m1 m5 m2 m3 0 m3 freq= 4.673GHz dB(S(1,1))=-3.442 dB(S(2,1)) dB(S(1,1)) -20 m4 -40 -60 -80 2 3 4 5 6 7 freq, GHz m4 freq= 4.086GHz dB(S(1,1))=-46.128 m5 freq=4.221GHz dB(S(1,1))=-2.468 (a) (b) Figure 4.6 Initial results and layout for C-Band filter ENG499 CAPSTONE PROJECT REPORT 44 4.2 Design of Ka-Band Filter using LTCC This filter was designed to operate at center frequency of 28GHz. The first step will be to setup substrate layers and simulation parameters in ADS. An alternative LTCC substrate with different dielectric constant and thickness was used in this design due to errors encountered during simulation. 4.2.1 ADS Setup for Ka-Band Filter For ADS setup, we need to define substrate layer properties and setup s-parameters. The dielectric constant of LTCC substrate was defined as r 7.84 with 100 m height, and loss tangent (tan ) of 0.001. The test frequency range will be from 20GHz to 36GHz. Sample points were set at 999. (a) (b) (c) Figure 4.7 (a) Substrate layer (b) Layout layers (c) S-Parameters settings for 28GHz filter ENG499 CAPSTONE PROJECT REPORT 45 4.2.2 Dimensions of Ka-Band Filter The initial filter dimensions can be calculated from equations listed in Chapter 2.2.4 and also using ADS LineCalc function. First, we calculate the dimension of input lines. They are configured to provide 50 impedance to match the SMA connectors. Dielectric constant r = 7.84 Substrate Thickness h = 100um Conductor Thickness t = 17um Characteristic impedance, Z 0 = 50 Loss Tangent Tan = 0.001 Using LineCalc, we determine the length and width of the input lines. Figure 4.8 LineCalc for input lines (Ka-Band) To demonstrate the accuracy of LineCalc, manual calculation of the values was done as listed below. re r 1 r 1 2 h 1 12 2 W 0.5 7.84 1 7.84 1 100 1 12 2 2 106.49 5.394 0.5 W W Zc h 1.393 0.677 In h 1.444 re 1 120 106.49 106.49 100 1.393 0.677 In 100 1.444 5.394 50 1 Setting of single 50ohm port in ADS is shown below as well. ENG499 CAPSTONE PROJECT REPORT 46 Figure 4.9 Setting of single mode 50ohms port (Ka-Band) Specifications of the filter design with central frequency of 28GHz, low cut-off frequency of 25GHz and high cut-off 31GHz. Step 1: Normalized Bandwidth, 2 1 31 25 0.214 0 28 Step 2: Next, the parameters for the 7 coupling structures are calculated using Equations (11), (12), (13). j 1 0.534 J j , j 1 2 0.259 3 0.195 4 0.185 5 0.195 6 0.259 7 0.534 Y0 Step 3: Followed by the even and odd impedances, j ( Z 0 e ) j , j 1 () 1 90.9 2 66.3 3 61.6 4 60.9 5 61.6 6 66.3 7 90.9 ( Z 0 o ) j , j 1 () 37.6 40.4 42.2 42.5 42.2 40.4 37.6 ENG499 CAPSTONE PROJECT REPORT 47 Step 4: From the ( Z0e ), ( Z0o ) values, we can evaluate line length l, width W and line gap S values using LineCalc. j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 46 82 89 90 89 82 46 34 68 92 97 92 68 34 l ' j ( m) 1285 1213 1196 1194 1196 1213 1285 Figure 4.10 LineCalc for coupling lines (Ka-Band) For guided wavelength, g 0 ( f ) re 3 x108 (28 x109 ) 5.394 4612.4 m Using equation (16), length of each coupling structure is roughly: ENG499 CAPSTONE PROJECT REPORT 48 l' j gj 2d 4 4612.4 m 2(16.5 m) 4 1123.1 m Considering d jj 1 remains constant throughout and offset value d = 0.165 x h where h is the substrate material thickness 100 m . ENG499 CAPSTONE PROJECT REPORT 49 4.2.3 Initial Design for Ka-Band Filter The initial design simulation results using values obtained from above steps. Center Frequency: 22GHz Bandwidth: 536MHz Insertion Loss (IL): -5.031dB Return Loss (RL): -1.831dB We are looking to achieve center frequency of 28GHz, low and high cut-off frequency at 25GHz and 31GHz respectively. S21 response is also not flat. The result was unsatisfactory. Seven coupled line with different lengths ( m ) L1,L7=1285 L2,L6=1213 L3,L5=1196 L4=1194 W1,W7=46 Seven coupled line with different widths ( m ) W2,W6=82 W3,W5=89 W4=90 Seven coupled line with different spacing ( m ) S1,S7=34 S2,S6=68 S3,S5=92 S4=97 11067x1219x200 Overall Dimension ( m ) Table 4.2 Initial dimensions for Ka-Band filter m1 freq= 19.39GHz dB(S(1,1))=-3.141 m3 freq= 22.01GHz dB(S(2,1))=-5.031 m1 m3 m2 0 m4 -20 dB(S(2,1)) dB(S(1,1)) m2 freq= 24.75GHz dB(S(1,1))=-2.955 -40 -60 -80 10 15 20 25 30 35 40 freq, GHz m4 freq= 21.20GHz dB(S(1,1))=-28.512 (a) (b) Figure 4.11 Initial results and layout for Ka-Band filter ENG499 CAPSTONE PROJECT REPORT 50 4.3 Sensitivity Analysis (LTCC) To fine-tune the filters, adjustments will be made to physical dimensions such as length, width and line gaps to observe how these changes can influence resonator performance. Each parameter was tested from a range of values based on the initial design and modified further in steps to achieve the desired filter response. 4.3.1 Effects of Adjusting Resonator Length (LTCC) Based on equation (5), the resonator length is an important attribute affecting the resonant frequency since they are inversely proportional. To achieve a higher center frequency from the initial design, several different length values have been tested in the design. Based on the results shown in Figure 4.4 below, it can be concluded that decreasing resonator length will register an increase in center frequency. Length vs Frequency (5.3GHz) Length (um) 8000 6000 4000 2000 0 1 2 3 4 5 Length 5736 5175 4975 4675 4375 Frequency 4.08 4.38 4.81 5.1 5.42 Frequency (GHz) Length vs Frequency (28GHz) Length (um) 1500 1000 500 0 1 2 3 4 5 Length (um) 1285 1123 1023 943 923 Frequency (GHz) 22.01 23.7 25.94 28.05 28.56 Frequency (GHz) Chart 4.1 Plot of Length against Frequency ENG499 CAPSTONE PROJECT REPORT 51 4.3.2 Effects of Adjusting Resonator Width (LTCC) Based on the equation stated below, resonator width affects resistivity and conductive losses. [25] c Rs Z0 W (17) Where Rs denotes the conductor surface resistivity, and Z 0 represents the characteristic impedance of the microstrip. The following chart summarizes the effects of adjusting various width values in steps how the change affects the results. Except for slight improvement observed when reducing resonator width, there is not much significant change in S11 and S21 performance. S-Parameters (-dB) Width vs S-Parameters (5.3GHz) 10 8 6 4 2 0 Width (um) 1 2 3 4 5 6 7 8 9 10 11 44 94 144 194 244 344 444 544 644 744 844 S11 (dB) 1.72 2 2.12 2.18 2.59 2.32 1.97 1.84 1.54 1.37 1.22 S21 (dB) 4.91 4.35 4.17 4.06 3.5 3.86 4.4 4.64 5.29 5.73 6.17 Width (um) S-Parameters (-dB) Width vs S-Parameters (28GHz) 10 8 6 4 2 0 1 2 3 4 5 6 7 8 9 16 26 36 46 56 66 76 86 96 S11 (dB) 1.64 1.79 1.8 1.72 1.68 1.57 1.46 1.36 1.25 S21 (dB) 5.42 5.1 5.09 5.26 5.33 5.6 5.89 6.16 6.49 Width (um) Width (um) Chart 4.2 Plot of Width against S-Parameters ENG499 CAPSTONE PROJECT REPORT 52 4.3.3 Effects of Adjusting Resonator Line Gaps (LTCC) Line gaps or spacing between coupling structures affects the performance parameters by a great margin. By varying the spacing, the coupling effect will change thus affecting resulting bandwidth and insertion loss. It can be observed that increasing the coupling space significantly improves insertion and return loss for this design. The impact of altering spacing is recorded in chart 4.3 shown below. Space vs S-Parameters (5.3GHz) S-Parameters (-dB) 25 20 15 10 5 0 1 2 3 4 Spacing (um) 404 S11 (dB) 1.82 S21 (dB) 4.69 5 6 7 8 9 424 504 524 624 724 824 1024 1124 2.6 3.15 4 5.97 7.86 10.38 14.07 20.98 3.48 2.89 2.21 1.28 0.79 0.43 0.19 0.05 Space (um) Space vs S-Parameters (28GHz) S-Parameters (-dB) 50 40 30 20 10 0 1 2 3 4 5 6 7 8 17 34 83 133 153 183 203 233 S11 (dB) 1.44 1.83 4.63 6.45 12.7 30.14 28.45 26.06 S21 (dB) 5.82 5.03 2.13 1.48 0.61 0.45 0.48 0.45 Spacing (um) Space (um) Chart 4.3 Plot of Spacing against S-Parameters ENG499 CAPSTONE PROJECT REPORT 53 4.4 Final Design Numerous experimental simulations were done by varying the physical dimensions as discussed in the previous sections. The results gathered allow understanding of the factors affecting performance parameters and further optimization to obtain the final design. 4.4.1 Final Design for C-Band Filter Center Frequency: 5.25GHz Bandwidth: 500MHz Insertion Loss (IL): -0.161dB Return Loss (RL): -14.99dB The center frequency achieved was around 5.25GHz, low and high cut-off frequency at 5GHz and 5.5GHz respectively. Insertion loss was -0.161dB and Return loss was 14.99dB at 5.25GHz. Seven coupled line with different lengths ( m ) L1,L7=4395 L2,L6=4375 L3,L5=4375 L4=4375 W1,W7=494 Seven coupled line with different widths ( m ) W2,W6=526 W3,W5=547 W4=550 S1,S7=17 Seven coupled line with different spacing ( m ) S2,S6=1224 S3,S5=1399 S4=1434 42330x11134x1270 Overall Dimension ( m ) Table 4.3 Final dimensions of C-Band filter S21 S11 0 0 -20 Mag. [dB] Mag. [dB] -10 -20 -30 -40 -60 -40 -80 -50 4.0 4.5 5.0 5.5 Frequency ENG499 CAPSTONE PROJECT REPORT 6.0 6.5 7.0 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Frequency 54 m1 freq=5.000GHz dB(S(1,1))=-4.317 m3 freq=5.251GHz dB(S(2,1))=-0.161 m1 0 m3 m2 freq=5.500GHz dB(S(1,1))=-4.725 m2 m4 dB(S(2,1)) dB(S(1,1)) -20 -40 -60 -80 4.0 4.5 5.0 5.5 6.0 6.5 7.0 freq, GHz m4 freq=5.251GHz dB(S(1,1))=-14.993 (a) (b) Figure 4.12 Final results and layout for C-Band filter ENG499 CAPSTONE PROJECT REPORT 55 4.4.2 Final Design for Ka-Band Filter Center Frequency: 28.01GHz Bandwidth: 288MHz Insertion Loss (IL): -0.46dB Return Loss (RL): -25.56dB The center frequency achieved was 28.01GHz, low and high cut-off frequency at 26.57GHz and 29.45GHz respectively. Insertion loss was -0.46dB and Return Loss was -25.56 at 28.01GHz. Seven coupled line with different lengths ( m ) L1,L7=934 L2,L6=943 L3,L5=943 L4=943 W1,W7=46 Seven coupled line with different widths ( m ) W2,W6=82 W3,W5=89 W4=90 S1,S7=10 Seven coupled line with different spacing ( m ) S2,S6=183 S3,S5=207 S4=212 42330x11134x1270 Overall Dimension ( m ) Table 4.4 Final dimensions of Ka-Band filter S21 0 -10 -10 Mag. [dB] Mag. [dB] S11 0 -20 -30 -40 -20 -30 -40 -50 -50 -60 20 22 24 26 28 30 Frequency ENG499 CAPSTONE PROJECT REPORT 32 34 36 20 22 24 26 28 30 32 34 36 Frequency 56 m1 freq= 26.57GHz dB(S(1,1))=-3.167 m3 freq= 28.01GHz dB(S(2,1))=-0.455 m2 freq= 29.45GHz dB(S(1,1))=-3.073 m1 m3 m2 0 dB(S(2,1)) dB(S(1,1)) -10 m4 -20 -30 -40 -50 -60 20 22 24 26 28 30 32 34 36 freq, GHz m4 freq= 28.01GHz dB(S(1,1))=-25.561 (a) (b) Figure 4.13 Final results and layout for Ka-Band Filter ENG499 CAPSTONE PROJECT REPORT 57 CHAPTER 5: FILTER DESIGN USING FR4 5.1 Design of Filter using FR4 This modified design was configured to operate at center frequency of 1.5GHz. Same approach as LTCC filter, first step will be to setup substrate layers and simulation parameters in ADS. 5.2 ADS Setup for FR4 Filter The dielectric constant of FR4 substrate was defined as r 4.7 and 1600 m height with loss tangent (tan ) of 0.027. The test frequency range will be from 1GHz to 2GHz. Sample points were set at 999. (a) (b) (c) Figure 5.1 (a) Substrate layer (b) Layout layers (c) S-Parameters settings for FR4 filter 5.3 Dimensions of FR4 Filter The initial filter dimensions can be calculated using equations listed in Chapter 2.2.4 and also using ADS LineCalc function. First, we calculate the dimension of input and output lines. They are configured to provide 50 impedance to match the SMA connectors. ENG499 CAPSTONE PROJECT REPORT 58 Dielectric constant r = 4.7 Substrate Thickness h = 1600um Conductor Thickness t = 17um Characteristic impedance, Z 0 = 50 Loss Tangent Tan = 0.027 Using LineCalc, we determine the length and width of the input lines. Figure 5.2 LineCalc for input lines (FR4) To demonstrate the accuracy of LineCalc, manual calculation of the values was done as listed below. re r 1 r 1 2 h 1 12 2 W 0.5 4.7 1 4.7 1 1600 1 12 2 2 2887 3.519 0.5 W W Zc h 1.393 0.677 In h 1.444 re 1 120 2887 2887 1600 1.393 0.677 In 1600 1.444 3.519 50 ENG499 CAPSTONE PROJECT REPORT 1 59 Setting of single 50ohm port in ADS is shown below. Figure 5.3 Setting of single mode 50ohms port (FR4) Specifications of the filter design with central frequency of 1.5GHz, low cut-off frequency of 1.2GHz and high cut-off 1.8GHz. Step 1: Normalized Bandwidth, 2 1 1.8 1.2 0.4 0 1.5 Step 2: Next, the parameters for the 7 coupling structures are calculated using Equations (11), (12), (13). j 1 0.729 J j , j 1 2 0.485 3 0.364 4 0.346 5 0.364 6 0.485 7 0.729 Y0 Step 3: Followed by the even and odd impedances, j ( Z 0 e ) j , j 1 () 1 2 113.05 85.98 3 74.80 4 73.27 5 74.80 6 7 85.98 113.05 ( Z 0 o ) j , j 1 () 40.12 38.42 38.68 38.42 37.51 ENG499 CAPSTONE PROJECT REPORT 37.51 40.12 60 Step 4: From the ( Z0e ), ( Z0o ) values, we can evaluate line length l, width W and line gap/spacing S values using LineCalc. j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 2113 2777 2821 2827 2821 2777 2113 362 1729 2296 2405 2296 1729 362 l ' j ( m) 27469 26774 26707 26699 26707 26774 27469 Figure 5.4 LineCalc for coupling lines (FR4) For guided wavelength, g 0 ( f ) re 3 x108 (1.5 x109 ) 3.519 106615.5 m Using equation (16), length of each coupling structure is roughly: ENG499 CAPSTONE PROJECT REPORT 61 l' j gj 2d 4 106615.5 m 2(264 m) 4 26126 m Considering d jj 1 remains constant throughout and offset value d = 0.165 x h where h is the substrate material thickness 1600 m . 5.4 Sensitivity Analysis (FR4) A with previous LTCC design, adjustments will be made to physical dimensions to observe how these changes can influence resonator performance. The observations are stated next. 5.4.1 Effects of Adjusting Resonator Length (FR4) As discussed previously, reducing resonator length register an increase in center frequency. Length vs Frequency (FR4) Length (um) 30000 25000 20000 15000 10000 5000 0 1 2 3 4 5 Length (um) 27469 27369 26969 26469 22969 Frequency (GHz) 1.291 1.295 1.315 1.338 1.538 Frequency (GHz) Chart 5.1 Plot of Length against Frequency 5.4.2 Effects of Adjusting Resonator Width It may be noted that reducing resonator width improves insertion and return losses but not by great margin. ENG499 CAPSTONE PROJECT REPORT 62 S-Parameters (-dB) Width vs S-Parameters (FR4) 15 10 5 0 Width (um) 1 2 3 4 5 6 7 8 9 10 513 913 1513 1713 1913 2113 2313 2513 2713 2913 S11 (dB) 7.66 S21 (dB) 9.242 9.281 9.897 10.38 10.62 10.37 11.28 11.69 12.09 12.47 7.757 7.221 8.465 6.487 7.045 5.871 5.514 5.252 5.036 Width (um) Chart 5.2 Plot of Width against S-Parameters 5.4.3 Effects of Adjusting Resonator Space (FR4) Adjusting line gap values affect the performance greatly. Space vs S-Parameters (FR4) S-Parameters (-dB) 25 20 15 10 5 0 Spacing (um) 1 2 12 62 3 4 100 162 5 6 362 562 7 8 9 10 11 12 762 962 1162 1362 1562 1762 S11 (dB) 9.06 8.99 8.97 8.78 8.47 8.03 7.66 7.29 6.96 6.98 6.22 8.02 S21 (dB) 8.92 9.11 9.25 9.52 10.4 11.3 12.3 13.4 14.6 15.9 17.2 20.8 Space (um) Chart 5.3 Plot of Spacing against S-Parameters ENG499 CAPSTONE PROJECT REPORT 63 5.5 Final Design for FR4 Filter In this section, simulation results will be provided based on values obtained from above calculations. Center Frequency: 1.291GHz Bandwidth: 220MHz Insertion Loss (IL): -10.37dB Return Loss (RL): -7.05dB We are looking to achieve center frequency of 1.5GHz, low and high cut-off frequency at 1.8GHz and 1.2GHz respectively. The S21 response was flat. Based on the overall results, this design was satisfactory and was recommended for fabrication. Seven coupled line with different lengths ( m ) L1,L7=27469 L2,L6=26774 L3,L5=26707 L4=26699 W1,W7=2113 Seven coupled line with different widths ( m ) W2,W6=2777 W3,W5=2821 W4=2827 S1,S7=362 Seven coupled line with different spacing ( m ) S2,S6=1729 S3,S5=2296 S4=2405 243615x33803x3200 Overall Dimension ( m ) Table 5.1 Final dimensions for FR4 filter ENG499 CAPSTONE PROJECT REPORT 64 S11 S21 0 -10 Mag. [dB] Mag. [dB] -20 -5 -10 -30 -40 -50 -15 -60 1.0 1.2 1.4 1.6 1.8 2.0 1.0 1.2 1.4 Frequency 1.6 1.8 2.0 Frequency m1 freq=1.181GHz dB(S(1,1))=-2.985 m3 freq=1.291GHz dB(S(1,1))=-7.045 m1 0 m3 m4 m2 freq=1.401GHz dB(S(1,1))=-3.003 m2 dB(S(2,1)) dB(S(1,1)) -10 -20 -30 -40 -50 -60 1.0 1.2 1.4 1.6 1.8 2.0 freq, GHz m4 freq=1.291GHz dB(S(2,1))=-10.374 (a) (b) Figure 5.5 Final results and layout for FR4 Filter ENG499 CAPSTONE PROJECT REPORT 65 CHAPTER 6: FABRICATION AND ASSEMBLY OF FILTER PROTOTYPE 6.1 Gerber files Exportation This chapter explains the preparation procedures before sending the prototype for fabrication. Once the filter design is completed, the next step will be exporting the design into gerber files before sending for fabrication. Gerber format refers to a CAD representation of a PCB and is widely accepted by PCB manufacturers as the standard format. The following are steps for gerber file preparation: i. ii. iii. iv. v. vi. vii. viii. Remove input ports from the design. Separate the design parts individually according to substrate layers, via holes, ground plane. Create a rectangular border sized roughly 3x3cm extending from the end point of the design for all individual layers. This border will act as markings for cutting the layers. Take note to customize the border to allow spacing for SMA connectors. Extend the input stripline to the border Export the individual layers to gerber format. PCB manufactures can charge based on material sheet size. Therefore, it is more cost effective to utilize the whole sheet area by combining individual layers to fit as much as possible into one sheet. Create a word document describing clearly all layer orientation from topmost to bottom layer. Also indicate sides to etch off, via hole locations and ground plane. To verify if the fabricated product is of the correct size, perform a printout from the gerber file. This printed copy will be the exact size and dimension as the fabricated product. Steps to export gerber file from ADS software: i. ii. iii. iv. v. vi. vii. Go to “File”, “Export”. Under “File Type”, select “Gerber” from the drop down list. Check that the correct file format is selected, for this case is “RX274X” Click on “More Options”, select the correct output unit “mm” for this case Click “OK” once done to export the design. A popup message will appear indicating “Exportation Complete”. Check for any warnings or errors in the log. ENG499 CAPSTONE PROJECT REPORT 66 Figure 6.1 Screen shot of gerber exportation from ADS Figure 6.2 Screen shot of gerber viewer ENG499 CAPSTONE PROJECT REPORT 67 6.2 Assembly of Filter Prototype The fabrication process will take about one week. Upon completion, the filter layers can be collected from the vendor and assembled in a technical workshop. Two sets of filter were fabricated using HASL and OSP finishing respectively. Figure 6.3 describes the fabrication process perform by our vendor “Precision Circuit Manufacturers Pte Ltd”. Figure 6.3 Fabrication process for multi-layer PCBs ENG499 CAPSTONE PROJECT REPORT 68 (a) (b) (c) (d) Figure 6.4 Filter layers (a) Filter layer orientation (b) Gerber view (c) OSP finishing (d) HASL finishing Basic technical tools such as soldering iron, hand drills, screw driver, cutter will be required and are easily available at local hardware shops. Extra components such as SMA connectors, nuts, screws, and masking tape will also need to be purchased. The following steps describe the assembly procedure. i. ii. iii. iv. v. Markings for drilling holes were drawn on the layers. Masking tape was used to secure the layers together for drilling. Drill the required screw and via holes. Tighten the layers together using screws and nuts. Solder the SMA connectors onto the board. ENG499 CAPSTONE PROJECT REPORT 69 Figure 6.5 Picture of assembled filter prototype ENG499 CAPSTONE PROJECT REPORT 70 CHAPTER 7: COMPARISON OF MEASURED AND SIMULATION RESULTS 7.1 Measurement of Results As discussed in proposed approach earlier in chapter 1, it is necessary to demonstrate workability of the proposed filter prototype. Here, we make comparisons between the simulated and measured results to determine if the prototype is working to expectations. Measurements can be taken using network analyzer available in SIM University or other electronics laboratory. The test apparatus and setup are listed as below. i. ii. iii. Agilent E8362B Network Analyzer Two sets of BNC adaptors Two sets of BNC to SMA connectors (b) (a) Figure 7.1 (a) Agilent E8362B Network Analyzer (b) Two sets of BNC adaptors with BNC to SMA connectors Testing was done on the filter set using OSP finishing. The HASL set was kept as backup. The network analyzer was configured to perform adaptive sweep from range of 10MHz to 5GHz and the measurements are compared against simulation results. Simulation Results Measured Results Center frequency at 1.291GHz Center frequency at 1.312GHz Insertion Loss of -10.37dB Insertion Loss of -7.75dB Return Loss of -7.05dB Return Loss of -7.26dB Table 7.1 Comparison between simulation and measured results Comparing the results, it can be observed that center frequency shifted around 0.021GHz, insertion and return loss also fare better for actual measurements. The extra losses could be due to tiny air gaps present when combining the layers plus other factors like material quality and component metallization loss. Changes in overall dielectric constant caused by shrinkage after co-firing could also possibly affect the quality. ENG499 CAPSTONE PROJECT REPORT 71 To summarize, the performance of the hardware prototype is comparable to simulation and can be considered a success based on the results achieved. S11 S21 0 -10 Mag. [dB] Mag. [dB] -20 -5 -10 -30 -40 -50 -15 -60 1.0 1.2 1.4 1.6 1.8 2.0 1.0 1.2 Frequency 1.4 1.6 1.8 2.0 Frequency m1 freq=1.181GHz dB(S(1,1))=-2.985 m3 freq=1.291GHz dB(S(1,1))=-7.045 m1 0 m3 m4 m2 freq=1.401GHz dB(S(1,1))=-3.003 m2 dB(S(2,1)) dB(S(1,1)) -10 -20 -30 -40 -50 -60 1.0 1.2 1.4 1.6 1.8 2.0 freq, GHz m4 freq=1.291GHz dB(S(2,1))=-10.374 (a) (b) Figure 7.2 (a) Simulation results (b) Measured results ENG499 CAPSTONE PROJECT REPORT 72 CHAPTER 8: CONCLUSION To conclude, this paper puts forward details on design modelling, simulation and fabrication of wide-band multilayer edge-coupled BPF using LTCC technology. This project has been an incredible experience for me. It proved to be a daunting task to handle a project of such magnitude from scratch. By completing this project, I have managed to gain valuable knowledge in both hardware and software aspects of building a filter prototype. Based on initial objectives, the hardware prototype performed to expectations with low insertion and return loss. The results proved that the design was feasible and suitable for both C and Ka-Band MCM applications. However, due to time constraints and various issues encountered along the way. The simulation results for LTCC are only reasonably satisfactory at this point. Given more time, better results can definitely be achieved. ENG499 CAPSTONE PROJECT REPORT 73 CHAPTER 9: SUGGESTION FOR FURTHER WORKS To improve the filter overall performance, some of the following suggestions might be implemented. More testing should be done to further improve insertion and return loss. Such as extending the experiment scope to test out different substrate materials and make changes to the current design by adding taps or stubs and observe if better results can be achieved. The parallel coupling structures may also be titled or folded in suitable angles such as similar to the structure of hairpin filter topology to reduce overall dimensions. By implementing metallic enclosure will help to reduce housing loss and stabilize characteristic impedance and effective dielectric constant due to conducting top and side walls. To improve the Q factor, better resonator plating such as silver may also be considered. The filter layers can also be aligned more professionally using proper laminating techniques. However, these methods will add on to the budget cost considerably. ENG499 CAPSTONE PROJECT REPORT 74 REFERENCES [1] LTCC Technology, retrieved 7th August 2010 from, http://www.ltcc-consulting.com [2] What is LTCC?, Retrieved 8th August 2010 from, http://www.ltcc.de/en/whatis.php [3] LTCC Technology for Sensor-and RF-Applications, Retrieved 10th August 2010 from, http://www.koaeurope.de/at/koa/downloads/LTCC12-2007.pdf [4] LTCC Examples and Solutions, Retrieved 8th August 2010 from, http://www.ltcc.de/en/examples.php [5] Jia-Sheng Hong, MJ Lan Caster, ‘Microstrip Lines’, ‘Microstrip Filters for RFMicrowave Applications’, New York: John Wiley & Son Inc, 2001, pp. 77-84 [6] Jia-Sheng Hong, MJ Lan Caster, ‘Coupled Lines’, ‘Microstrip Filters for RFMicrowave Applications’, New York: John Wiley & Son Inc, 2001, pp. 84-89 [7] M. Dhieb, M.Ketata, M. Lhiani, H. Ghariani, ‘Microstrip Bandpass Filters for Ultra Wide Band (UWB) [3.1-5.1 GHz]’, Retrieved 16th August 2010 from, http://www.hypersciences.org/IJISTE/Iss.2-2010/IJISTE-2-2-2010.pdf [8] RF filter basic tutorial, Retrieved 16th August 2010 from, http://www.radioelectronics.com/info/rf-technology-design/rf-filters/rf-filter-basics-tutorial.php [9] R Lidwig, P Bretchko, ‘An Overview of RF Filter Design’, ‘RF Circuit Design – Theory and Applications’, Prentice-Hall, Inc., 2000, pp. 201-241 [10] RF and Microwave Filter, Retrieved 16th August 2010 from, http://en.wikipedia.org/wiki/RF_and_microwave_filter [11] Chebyshev Filter, Retrieved 20th August 2010 from, http://en.wikipedia.org/wiki/Chebyshev_filter [12] Jia-Sheng Hong, MJ Lan Caster, ‘Bandpass Filters’, ‘Microstrip Filters for RFMicrowave Applications’, New York: John Wiley & Son Inc, 2001, pp. 121-158 [13] Jia-Sheng Hong, MJ Lan Caster, ‘Network Analysis’, ‘Microstrip Filters for RFMicrowave Applications’, New York: John Wiley & Son Inc, 2001, pp. 7-10 [14] Advanced Design System (ADS), Retrieved 20th August 2010 from, http://www.home.agilent.com/agilent/product.jspx?cc=SG&lc=eng&ckey=1297113&nid =-34346.0.00&id=1297113 [15] Clyde F. Coombs, Jr., ‘Printed Circuit Board Surface Finishes’, ‘Printed Circuits Handbook, Sixth Edition’, New York: McGraw Hill Handbooks, 2008, pp. 751-760 [16] Clyde F. 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A. Butt, A.E. Nadeem, A. Hasan, ‘Sensitivity Analysis’, ‘A Low Cost RF Oscillator Incorporating a Folded Parallel Coupled Resonator’, Retrieved 2th May 2011 from, http://www.jpier.org/PIERC/pierc09/07.09062505.pdf ENG499 CAPSTONE PROJECT REPORT 76 APPENDIX A ENG499 CAPSTONE PROJECT REPORT 77 ENG499 CAPSTONE PROJECT REPORT 78 APPENDIX B ENG499 CAPSTONE PROJECT REPORT 79 ENG499 CAPSTONE PROJECT REPORT 80 APPENDIX C ENG499 CAPSTONE PROJECT REPORT 81 ENG499 CAPSTONE PROJECT REPORT 82 APPENDIX D ENG499 CAPSTONE PROJECT REPORT 83 ENG499 CAPSTONE PROJECT REPORT 84 ENG499 CAPSTONE PROJECT REPORT 85 APPENDIX E 3D-EM view and Schematic Diagrams: (a) (b) (c) (d) 3D-EM view (a) Front view (b) Top view (c) Back view (d) Side view C-Band design schematic ENG499 CAPSTONE PROJECT REPORT 86 Ka-Band design schematic FR4 design schematic ENG499 CAPSTONE PROJECT REPORT 87 APPENDIX F Other LTCC Designs (C-Band) Design 1: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 344 526 547 550 547 526 344 177 524 699 734 699 524 177 l ' j ( m) 4975 4975 4975 4975 4975 4975 4975 m4 freq=4.670GHz dB(S(2,1))=-3.627 m1 freq=4.164GHz dB(S(1,1))=-3.018 m2 freq=5.157GHz dB(S(1,1))=-3.336 m1 m3 m4 m2 0 dB(S(2,1)) dB(S(1,1)) -20 -40 -60 Center Frequency:4.66GHz Bandwidth:0.993GHz Insertion Loss:-3.627dB Return Loss:-2.487dB -80 2 3 4 5 6 7 freq, GHz m3 freq=4.670GHz dB(S(1,1))=-2.487 Design 2: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 444 626 647 650 647 626 444 177 524 699 734 699 524 177 l ' j ( m) 4375 4375 4375 4375 4375 4375 4375 m1 freq= 4.699GHz dB(S(1,1))=-2.949 0 m3 freq=5.253GHz dB(S(1,1))=-1.973 m3 m4 m1 m2 m2 freq= 5.796GHz dB(S(1,1))=-2.706 dB(S(2,1)) dB(S(1,1)) -20 Center Frequency:5.25GHz Bandwidth:1.097GHz Insertion Loss:-4.401dB Return Loss:-1.973dB ENG499 CAPSTONE PROJECT REPORT -40 -60 -80 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 freq, GHz m4 freq= 5.253GHz dB(S(2,1))=-4.401 88 Design 3: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 194 376 397 400 397 376 194 177 524 699 734 699 524 177 l ' j ( m) 4375 4375 4375 4375 4375 4375 4375 m3 freq= 5.257GHz dB(S(2,1))=-1.822 m1 freq=4.705GHz dB(S(1,1))=-3.491 m3 m4 m1 0 m2 freq=5.796GHz dB(S(1,1))=-3.125 m2 dB(S(2,1)) dB(S(1,1)) -20 -40 -60 Center Frequency:5.26GHz Bandwidth:1.091GHz Insertion Loss:-1.822dB Return Loss:-4.672dB -80 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 freq, GHz m4 freq= 5.257GHz dB(S(1,1))=-4.672 Design 4: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 344 526 547 550 547 526 344 157 524 699 734 699 524 157 l ' j ( m) 4375 4375 4375 4375 4375 4375 4375 m3 freq=5.258GHz dB(S(2,1))=-3.817 m1 freq=4.693GHz dB(S(1,1))=-2.972 m4 m3 m1 0 m2 freq=5.815GHz dB(S(1,1))=-2.654 m2 dB(S(2,1)) dB(S(1,1)) -20 Center Frequency:5.26GHz Bandwidth:1.122GHz Insertion Loss:-3.817dB Return Loss:-2.347dB ENG499 CAPSTONE PROJECT REPORT -40 -60 -80 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 freq, GHz m4 freq=5.258GHz dB(S(1,1))=-2.347 89 Design 5: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 344 526 547 550 547 526 344 17 1024 1199 1234 1199 1024 17 l ' j ( m) 4375 4375 4375 4375 4375 4375 4375 m3 freq=5.248GHz dB(S(2,1))=-0.178 m1 freq=4.938GHz dB(S(1,1))=-2.881 m2 freq=5.559GHz dB(S(1,1))=-3.137 m1 m3 m2 m4 0 dB(S(2,1)) dB(S(1,1)) -20 Center Frequency:5.25GHz Bandwidth:0.621GHz Insertion Loss:-0.178dB Return Loss:-14.284dB ENG499 CAPSTONE PROJECT REPORT -40 -60 -80 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 freq, GHz m4 freq=5.248GHz dB(S(1,1))=-14.284 90 APPENDIX G Other LTCC Designs (Ka-Band) Design 1: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 46 82 89 90 89 82 46 34 68 92 97 92 68 34 l ' j ( m) 1285 1213 1196 1194 1196 1213 1285 m3 m2 freq=28.56GHz freq=32.07GHz dB(S(2,1))=-5.253 dB(S(1,1))=-3.116 m1 m4 m3 m2 m1 freq=25.09GHz dB(S(1,1))=-3.089 0 dB(S(2,1)) dB(S(1,1)) -20 -40 -60 Center Frequency:25.56GHz Bandwidth:6.98GHz Insertion Loss:-5.253dB Return Loss:-1.721dB -80 10 15 20 25 30 35 40 freq, GHz m4 freq=28.56GHz dB(S(1,1))=-1.721 Design 2: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 56 92 99 100 99 92 56 34 68 92 97 92 68 34 l ' j ( m) 943 943 943 943 943 943 943 m1 freq= 24.64GHz dB(S(1,1))=-3.166 m3 freq= 28.00GHz dB(S(2,1))=-5.330 m1 0 m4 m3 m2 freq= 31.37GHz dB(S(1,1))=-2.616 m2 dB(S(2,1)) dB(S(1,1)) -20 Center Frequency:28GHz Bandwidth:6.73GHz Insertion Loss:-5.33dB Return Loss:-1.684dB ENG499 CAPSTONE PROJECT REPORT -40 -60 -80 10 15 20 25 30 35 40 freq, GHz m4 freq= 28.00GHz dB(S(1,1))=-1.684 91 Design 3: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 26 62 69 70 69 62 26 34 68 92 97 92 68 34 l ' j ( m) 943 943 943 943 943 943 943 m1 freq= 24.53GHz dB(S(1,1))=-3.288 m3 freq= 28.00GHz dB(S(2,1))=-5.097 m1 0 m4 m3 m2 freq=31.56GHz dB(S(1,1))=-2.783 m2 dB(S(2,1)) dB(S(1,1)) -20 -40 -60 Center Frequency:28GHz Bandwidth:7.03GHz Insertion Loss:-5.097dB Return Loss:-1.794dB -80 10 15 20 25 30 35 40 freq, GHz m4 freq= 28.00GHz dB(S(1,1))=-1.794 Design 4: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 46 82 89 90 89 82 46 20 83 107 112 107 83 20 l ' j ( m) 943 943 943 943 943 943 943 m3 freq=28.02GHz dB(S(2,1))=-3.489 m1 freq=24.98GHz dB(S(1,1))=-3.004 m1 m4 m3 0 m2 freq=31.02GHz dB(S(1,1))=-2.840 m2 dB(S(2,1)) dB(S(1,1)) -10 Center Frequency:28.02GHz Bandwidth:6.04GHz Insertion Loss:-3.489dB Return Loss:-2.872dB ENG499 CAPSTONE PROJECT REPORT -20 -30 -40 -50 -60 20 22 24 26 28 30 32 34 36 freq, GHz m4 freq=28.02GHz dB(S(1,1))=-2.872 92 Design 5: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 46 82 89 90 89 82 46 10 183 207 212 207 183 10 l ' j ( m) 929 943 943 943 943 943 929 m3 freq= 28.00GHz dB(S(2,1))=-0.447 m1 freq= 26.57GHz dB(S(1,1))=-2.982 m2 freq=29.46GHz dB(S(1,1))=-3.018 m1 m3 m2 0 dB(S(2,1)) dB(S(1,1)) -10 Center Frequency:28GHz Bandwidth:2.89GHz Insertion Loss:-0.447dB Return Loss:-30.184dB ENG499 CAPSTONE PROJECT REPORT -20 m4 -30 -40 -50 -60 20 22 24 26 28 30 32 34 36 freq, GHz m4 freq= 28.00GHz dB(S(1,1))=-30.184 93 APPENDIX H Other FR4 Designs Design 1: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 2113 2777 2821 2827 2821 2777 2113 362 1729 2296 2405 2296 1729 362 l ' j ( m) 26469 25774 25707 25699 25707 25774 26469 m3 freq=1.338GHz dB(S(1,1))=-6.830 m1 freq=1.226GHz dB(S(1,1))=-3.164 m1 0 m2 freq=1.451GHz dB(S(1,1))=-3.151 m2 m3 m4 dB(S(2,1)) dB(S(1,1)) -10 Center Frequency:1.338GHz Bandwidth:0.225GHz Insertion Loss:-10.452dB Return Loss:-6.83dB -20 -30 -40 -50 -60 1.0 1.2 1.4 1.6 1.8 2.0 freq, GHz m4 freq=1.338GHz dB(S(2,1))=-10.452 Design 2: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 2513 3177 3221 3227 3221 3177 2513 362 1729 2296 2405 2296 1729 362 l ' j ( m) 22969 22274 22207 22199 22207 22274 22969 m3 freq=1.536GHz dB(S(1,1))=-5.514 m1 freq=1.414GHz dB(S(1,1))=-3.038 m1 0 m2 freq=1.658GHz dB(S(1,1))=-3.006 m2 m3 m4 dB(S(2,1)) dB(S(1,1)) -10 Center Frequency:1.536GHz Bandwidth:0.244GHz Insertion Loss:-11.692dB Return Loss:-5.514dB ENG499 CAPSTONE PROJECT REPORT -20 -30 -40 -50 -60 1.0 1.2 1.4 1.6 1.8 2.0 freq, GHz m4 freq=1.536GHz dB(S(2,1))=-11.692 94 Design 3: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 1713 2377 2421 2427 2421 2377 1713 362 1729 2296 2405 2296 1729 362 l ' j ( m) 22969 22274 22207 22199 22207 22274 22969 m1 freq=1.403GHz dB(S(1,1))=-2.910 m3 freq=1.532GHz dB(S(1,1))=-8.465 m1 0 m2 freq=1.660GHz dB(S(1,1))=-3.044 m2 m3 m4 dB(S(2,1)) dB(S(1,1)) -10 Center Frequency:1.532GHz Bandwidth:0.257GHz Insertion Loss:-10.375dB Return Loss:-8.465dB -20 -30 -40 -50 -60 1.0 1.2 1.4 1.6 1.8 2.0 freq, GHz m4 freq=1.532GHz dB(S(2,1))=-10.375 Design 4: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 1713 2377 2421 2427 2421 2377 1713 562 1929 2496 2605 2496 1929 562 l ' j ( m) 22969 22274 22207 22199 22207 22274 22969 m1 freq= 1.414GHz dB(S(1,1))=-3.086 m3 freq= 1.531GHz dB(S(1,1))=-8.026 m1 0 m2 freq= 1.648GHz dB(S(1,1))=-3.069 m2 m3 m4 dB(S(2,1)) dB(S(1,1)) -10 Center Frequency:1.531GHz Bandwidth:0.234GHz Insertion Loss:-11.322dB Return Loss:-8.026dB ENG499 CAPSTONE PROJECT REPORT -20 -30 -40 -50 -60 1.0 1.2 1.4 1.6 1.8 2.0 freq, GHz m4 freq= 1.531GHz dB(S(2,1))=-11.322 95 Design 5: j W j , j 1 ( m) S j , j 1 ( m) 1 2 3 4 5 6 7 1713 2377 2421 2427 2421 2377 1713 162 3529 4096 4205 4096 3529 162 l ' j ( m) 21969 21274 21207 21199 21207 21274 21969 m1 freq=1.503GHz dB(S(1,1))=-3.055 m3 freq= 1.598GHz dB(S(1,1))=-13.226 m1 0 dB(S(2,1)) dB(S(1,1)) ENG499 CAPSTONE PROJECT REPORT m2 m3 m4 -10 Center Frequency:1.598GHz Bandwidth:0.19GHz Insertion Loss:-16.964dB Return Loss:-13.226dB m2 freq= 1.693GHz dB(S(1,1))=-3.033 -20 -30 -40 -50 -60 1.0 1.2 1.4 1.6 1.8 2.0 freq, GHz m4 freq= 1.598GHz dB(S(2,1))=-16.964 96 APPENDIX I Meeting Log 1 1 2 3 4 5 6 Date Time Duration Venue Student Name Project / Supervisor Name 7 Review of Previous Meeting and progress Minutes of current meeting 8 9 Action items/ Targets to achieve ENG499 CAPSTONE PROJECT REPORT August 01, 2010 9:30am – 11:30am 2 hours UniSIM Room 4.25 Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-Chip-Module (MCM) Applications / Dr Lum Kum Meng Nil 1. Discussion on project scope. 2. Breakdown of project Expectations, Objectives and Schedule. 3. Supervisor conducted brief intro on the usage of ADS (Advanced Design System) software for circuit design and simulation. 4. Highlights on the 1st design for project. 5. Introduction on available equipment in campus. (Network Analyzer 300KHz – 300GHz) , (Spectrum Analyzer 9KHz – 3GHz), (Signal Generator 9KHz – 3GHz) 6. To work on design within the above range (around 1GHz). 1. To sent in meeting log by end of day. 2. To enhance personal understanding on LTCC filter design via reference books by next meeting. 3. To submit Proposal by 28 Aug 10. 4. To research on BPF design using LTCC Technology and completion of 1st design and simulation phase by Nov10. 5. To submit Interim Report by 8 Nov. 6. To enhance on 1st design and fabrication (optional) by Feb11 (Before CNY). 7. To start on thesis after Feb11 (after 97 10 Other comment/Areas to improve 11 Reference materials 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT CNY), completion by May11. 1. Next meeting will be held on 07 Aug 46pm at Room 3.17 Nil Completed 1st meeting log. 98 Meeting Log 2 1 2 3 4 5 6 7 8 9 Date Time Duration Venue Student Name Project / Supervisor Name August 07, 2010 4:00pm – 6:00pm 2 hours Blk82 Room 2.02 Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-ChipModule (MCM) Applications / Dr Lum Kum Meng Review of Previous Meeting More read up to enhance personal and progress understanding on filters using LTCC technology. Minutes of current meeting 1. ADS demonstration on schematic and momentum platform. 2. Understand modeling approach of LTCC filter using ADS. 3. Guidelines to project proposal write-up. Action items/ Targets to achieve 10 Other comment/Areas to improve 11 Reference materials 1. To sent in meeting log by end of day. 2. To enhance personal understanding on LTCC filter design via websites/reference books. 3. Research on S-Parameters. 4. Commence on proposal write-up. 5. Commence or LTCC filter modeling. 1. Next meeting will be held on 21 August 2010 3:00pm – 5:00pm.Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design Theory and Applications, 2000 by PrenticeHall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT Completed 2nd meeting log. 99 Meeting Log 3 1 2 3 4 5 6 Date Time Duration Venue Student Name Project / Supervisor Name 7 Review of Previous Meeting and progress Minutes of current meeting 8 9 Action items/ Targets to achieve 10 Other comment/Areas to improve 11 Reference materials August 21, 2010 3:00pm – 5:00pm 2 hours Blk82 Room 2.02 Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-ChipModule (MCM) Applications / Dr Lum Kum Meng 1. To read up on Chebyshev Filters. 1. Technical discussion on filter design and implementation. 2. Further discussion on usage of ADS momentum platform for filter design 3. Further discussion on proposal write-up techniques. 1. To sent in meeting log by end of day. 2. To complete project proposal by 6 Sep 2010. 3. Presentation of 1st filter design prototype and simulation results. 1. Next meeting will be held on 4 Sep 2010 3:00pm – 5:00pm.Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design Theory and Applications, 2000 by PrenticeHall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ 4. What is LTCC? , Retrieved 08 August 2010, http://www.ltcc.de/en/whatis.php 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT Completed 3rd meeting log. Commence on proposal write-up. Commence on LTCC filter modeling. 100 Meeting Log 4 1 2 3 4 5 6 Date Time Duration Venue Student Name Project / Supervisor Name 7 Review of Previous Meeting and progress 8 Minutes of current meeting 1. Technical discussion on edge-coupled filter design. 2. Further troubleshooting of problems on ADS modeling. 3. Further discussion on proposal write-up techniques. 9 Action items/ Targets to achieve 1. To sent in meeting log by end of day. 2. To complete project proposal by 5 Sep 2010 1200HRS 1. Next meeting will be held on 18 Sep 2010 3:00pm – 5:00pm.Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design - 10 Other comment/Areas to improve 11 Reference materials September 04, 2010 3:00pm – 5:00pm 2 hours Blk82 Room 2.02 Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-ChipModule (MCM) Applications / Dr Lum Kum Meng 1. Continue working on filter design and proposal writeup. Theory and Applications, 2000 by PrenticeHall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ What is LTCC? , Retrieved 08 August 2010, http://www.ltcc.de/en/whatis.php 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT Completed 4rd meeting log. Commence on proposal write-up. Commence on LTCC filter modeling. 101 Meeting Log 5 1 2 3 4 5 6 7 8 Date Time Duration Venue Student Name Project / Supervisor Name Review of Previous Meeting and progress Minutes of current meeting 9 Action items/ Targets to achieve 1 0 Other comment/Area s to improve Reference materials 1 1 September 18, 2010 3:00pm – 5:00pm 2 hours HQ Room 4.23 Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-Chip-Module (MCM) Applications / Dr Lum Kum Meng 1. Continue working on filter design and enhance performance of filter 1. Technical discussion and troubleshooting on edgecoupled filter design. 2. Analysis on current filter performance 1. To sent in meeting log by end of day. 2. Presentation on improvised filter performance 3. To demonstrate more understanding on multilayer filter design 1. Next meeting will be held on 16 Oct 2010 3:00pm – 5:00pm.Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design - Theory and Applications, 2000 by Prentice-Hall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ 4. Functions and Type of Network Analyzer, Retrieved 21 August 2010, http://en.wikipedia.org/wiki/Network_analyzer_%28electri cal%29 1 2 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT Completed 5th meeting log. Completed proposal write-up. Commence on LTCC filter modeling. 102 Meeting Log 6 1 2 3 4 5 6 7 Date Time Duration Venue Student Name Project / Supervisor Name October 16, 2010 12:30pm – 3:00pm 2.5 hours Blk82 Lab 3.11 Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-ChipModule (MCM) Applications / Dr Lum Kum Meng Review of Previous Meeting 1. Continue working on filter design and and progress enhance performance of filter 8 Minutes of current meeting 1. Technical discussion and troubleshooting on edge-coupled filter design. 2. Analysis on current filter performance 9 Action items/ Targets to achieve 1. To sent in meeting log by end of day. 2. Presentation on improvised filter performance 3. To demonstrate more understanding on multilayer filter design. 4. Interim Report to be submitted on 8 Nov 2010 by 1200 HRS. 1. Next meeting will be held on Jan 2011.Date, Time and Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design - 10 Other comment/Areas to improve 11 Reference materials Theory and Applications, 2000 by PrenticeHall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT Completed 6th meeting log. Completed proposal write-up. Commence on LTCC filter modeling. To complete Interim Report by 8 Nov 2010 103 Meeting Log 7 1 2 3 4 5 6 7 Date Time Duration Venue Student Name Project / Supervisor Name December 08, 2010 08:00pm – 9:30pm 1.5 hours Tampines Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-ChipModule (MCM) Applications / Dr Lum Kum Meng Review of Previous Meeting 1. Discussion of problems faced on Edgeand progress Coupled bandpass filter design 2. Troubleshooting of ADS design layout 8 Minutes of current meeting 1. Technical discussion and troubleshooting on edge-coupled filter design. 2. Analysis on current filter performance 9 Action items/ Targets to achieve 1. To sent in meeting log by end of day. 2. Presentation on improvised filter performance 3. To demonstrate more understanding on multilayer filter design. 4. Interim Report to be submitted on 8 Nov 2010 by 1200 HRS. 1. Next meeting will be held on Jan 2011.Date, Time and Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design - 10 Other comment/Areas to improve 11 Reference materials Theory and Applications, 2000 by PrenticeHall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ 4. M. Dhieb, M. Ketata, M. Lahiani, H. Ghariani, Microstrip Bandpass Filters for Ultra Wide Band (UWB) [3.1-5.1 GHz], 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT Completed 7th meeting log. Completed Interim Report. 104 Meeting Log 8 1 2 3 4 5 6 Date Time Duration Venue Student Name Project / Supervisor Name 7 Review of Previous Meeting and progress Minutes of current meeting 8 9 Action items/ Targets to achieve 10 Other comment/Areas to improve Reference materials 11 February 12, 2011 10:00am – 12:00pm 2 hours HQ Lab 5.17B Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-Chip-Module (MCM) Applications / Dr Lum Kum Meng 1. Continue working on filter design and enhance performance of filter. 1. Technical discussion on filter performance. 2. Demonstration on fabrication process. Gerber file creation. 1. 2. 3. 1. To sent in meeting log by end of day. Final improvement of filter response. Completion of fabrication process Next meeting will be held on 26 Feb 2011 10:00am – 12:00pm.Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design - Theory and Applications, 2000 by Prentice-Hall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ 4. M. Dhieb, M. Ketata, M. Lahiani, H. Ghariani, Microstrip Bandpass Filters for Ultra Wide Band (UWB) [3.1-5.1 GHz], Retrieved 16 August 2010, http://www.hypersciences.org/IJISTE/Iss.22010/IJISTE-2-2-2010.pdf 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT 5. http://edocs.soco.agilent.com/display/ads2008U 2/Gerber+Translator 1. Completed 8th meeting log. 2. Working on final improvement of filter response. 3. Prepare gerber file for fabrication. 105 Meeting Log 9 1 2 3 4 5 6 Date Time Duration Venue Student Name Project / Supervisor Name 7 Review of Previous Meeting and progress Minutes of current meeting 8 9 Action items/ Targets to achieve 10 Other comment/Areas to improve Reference materials 11 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT February 26, 2011 10:00am – 12:00pm 2 hours HQ Lab 5.17B Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-Chip-Module (MCM) Applications / Dr Lum Kum Meng 1. Final improvement of filter performance. 1. Final verification of gerber files for fabrication. 2. Final verification of filter performance. 1. To sent in meeting log by end of day. 2. Presentation on understanding of filter design concepts. 3. Update on fabrication performance. 1. Next meeting will be held on 12 Mar 2011 10:00am – 12:00pm.Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design - Theory and Applications, 2000 by Prentice-Hall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ 4. M. Dhieb, M. Ketata, M. Lahiani, H. Ghariani, Microstrip Bandpass Filters for Ultra Wide Band (UWB) [3.1-5.1 GHz], Retrieved 16 August 2010, http://www.hypersciences.org/IJISTE/Iss.22010/IJISTE-2-2-2010.pdf 5. http://edocs.soco.agilent.com/display/ads2008U2/ Gerber+Translator 6. http://www.sunstone.com/pcb-capabilities/leadfree-rohs/material-comparison.aspx Completed 9th meeting log. Completed gerber file for fabrication. Contacting vendor for fabrication. 106 Meeting Log 10 1 2 3 4 5 6 Date Time Duration Venue Student Name Project / Supervisor Name 7 Review of Previous Meeting and progress Minutes of current meeting 8 9 Action items/ Targets to achieve 10 Other comment/Areas to improve Reference materials 11 March 12, 2011 10:00am – 12:00pm 2 hours HQ Lab 5.17B Soong Wei Qiang Embedded Edge-Coupled BPF using Multilayer LTCC Technology for Ka-Band Multi-Chip-Module (MCM) Applications / Dr Lum Kum Meng 1. Final improvement of filter performance. 1. Final verification of gerber files for fabrication. 2. Final verification of filter performance. 3. Update on fabrication progress. 1. To sent in meeting log by end of day. 2. Presentation on understanding of filter design concepts. 3. Testing and measurement of actual filter prototype. 1. Next meeting will be held on 26 Mar 2011 10:00am – 12:00pm.Venue to be announced upon confirmation. 1. R. Ludwig, P. Bretchko RF Circuit Design - Theory and Applications, 2000 by Prentice-Hall, Inc. pp 200, 241 2. Jia-Sheng Hong, M.J. Lan Caster, “Combline Filter,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001 pp 127-130 3. LTCC technology, Retrieved 07 August 2010, http://www.ltcc-consulting.com/ 12 How did you progress so far? (10 Excellent, 1 Poor) ENG499 CAPSTONE PROJECT REPORT 4. http://edocs.soco.agilent.com/display/ads2008U 2/Gerber+Translator 5. http://www.sunstone.com/pcb-capabilities/leadfree-rohs/material-comparison.aspx Completed 10th meeting log. Completed gerber file for fabrication. Contacting vendor for fabrication. 107