A brief description of all the
tasks/activities performed during
the internship, conclusions and
observations made, leading to
respective outcomes.
ANECHOIC
CHAMBER
[INTERNSHIP AT RIMMS
REPORT]
FATIMA IQBAL
BEE-11-A
290358
RF ANECHOIC CHAMBER
 A well protected room specifically designed in order to minimize and
absorb the reflections produced by radio frequency electromagnetic
waves.
 This chamber serves the major purpose in antenna designing, testing
various parameters of antenna such as gain, bandwidth, and impedance.
 The size of the chamber varies in accordance with its applications. Farfield measurements usually require a larger and costly chamber.
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ANTENNA
‘A metallic instrument that absorbs and emits the radio frequency electromagnetic
waves.’
There are various types of antennae depending upon its shape, size, and
applications.
TYPES OF ANTENNAS (On the basis of structure)
 Wire Antennas
Used in buildings, ships, space crafts
 Aperture Antennas
Used in aircraft and space crafts
 Reflector Antennas
Used in microwave communication and in tracking satellites
 Micro strip Antennas
Used in mobile phones, satellites etc.
 Array Antennas
Used to manage the radiation pattern
PARAMETERS
Typical parameters on the basis of which antenna is tested are
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Gain
Bandwidth
Radiation Pattern
Beamwidth
Polarization
Impedance
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ANTENNA DESIGN, ANALYSIS AND
STIMULATION
CST STUDIO SUITE
‘An industry-leading 3-D EM simulation software with various applications and
the ability to simulate antenna radiation patterns, performance and coupling in
practical environment.’
CST has thus proven to be useful in the designing of a variety of different types of
antennas such as horn antennas, wire antennas, printed antennas, and arrays.
Typical components of CST are:
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Navigation tree
Drawing plane
Variable’s list
Project messages windows
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MODELING
 The first and foremost step towards the antenna designing is to understand
the shape and the structure required for the respective application.
 Antenna with different shapes, sizes and dimensions can thus be designed
and visualized with the help of the CST STUDIO LITE.
 The material plays a significant role while designing the structure of antenna
and thus the most suitable material can be selected.
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SIMULATION
WAVE GUIDE PORT
Waveguide ports enable the stimulation and the energy absorption.
Steps
 Insert the waveguide port.
 Set the frequency range.
 Run Transient Solver.
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1D RESULTS
Next step in the designing of the antenna is to analyze and study the results
obtained after the stimulation.
Steps
In navigation tree go to 1D Results
 S-parameters
S-parameters can be described as the input-output relationship between ports in
an electrical system. Consider 2 ports called as Port 1 and Port 2, then the power
transferred from Port 2 to Port 1 can be represented as S12 and vice versa.
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 Smith Chart
A wonderful tool in order to visualize the impedance of a transmission line
and antenna system as a function of frequency.
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SETTING FIELD MONITORS
Field monitors such as Far-field or Electric filed with the respective frequency of
the antenna can be adjusted.
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Some of the antennas designed by us on the CST software are:
HELICAL ANTENNA
Helical antennas are usually easier to design.
 It consists of a tube with a circumference equal to one wavelength and wrap
wire in a helix spaced a quarter wavelength.
 The width of the conductor doesn’t matter in the design.
 With the increase in the number of turns, the directivity and the gain of the
antenna also increases.
3D-MODEL
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Frequency 2.45 GHz
Antenna gain 10 dB
Azimuth and elevation beamwidths: 45 degree
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S-parameters
Smith chart:
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MICROSTRIP PATCH ANTENNA
A single-layered design usually consisting of the following four parts:
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Patch
Ground plane
Substrate
Feeding part
Microstrip antenna has
 less radiation power
 narrow frequency bandwidth
 lesser directivity
SUBSTRATE
1. ROGER 5880 (Frequency 2.4 GHz)
MODEL:
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S-PARAMETERS:
SMITH CHART:
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2. FR-4 (Frequency 2.4 GHz)
MODEL:
S-PARAMETERS:
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SMITH CHART:
ANTENNA FABRICATION USING PCB
TECHNOLOGY
After designing the antennas on the CST
software, the Gerber file produced can then be
used in the fabrication of micro strip patch
antenna with the help of the LPFK mechanical
tools.
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Endmill cutter
Universal cutter
Contour
Spiral cutter
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PCB LAYOUT ON PROTEUS
CONTROL BOARD CIRCUIT
SCHEMETIC MODEL:
PCB LAYOUT
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RF BEACON CIRCUIT (FREQUENCY 243 MHz)
SCHEMETIC MODEL:
PCB LAYOUT
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EPILOGUE/CONCLUSION:
 Our Internship at RIMMS allowed us to have a deeper
insight into the often-neglected field of RF i.e., antenna
designing and stimulation.
 Working in the anechoic chamber allowed us to witness
several real-life problems faced during the antenna testing
and the steps taken in order to increase the accuracy level.
 Understanding an industry leading software CST studio
suite that plays a significant role in visualizing and
designing the antenna whilst studying its different
parameters.
 Getting to know the parameters such as gain, polarization
and frequencies on the basis of which the antennas are
tested
 Fabrication of the antennas in the RCMS lab allowed us to
witness how antennas designed on CST software are then
fabricated for its real life applications.
REFERENCES
 http://portugal.chapters.comsoc.org/files/2016/01/Slides_Talk_10_4.pdf
 https://www.microwavejournal.com/articles/29437-antenna-design-analysisand-simulation
 https://www.tutorialspoint.com/how-does-the-microstrip-antenna-work
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