Matching Impedance of Bluetooth Antenna Abstract— Bluetooth is a well-known, short-range technology for Wireless Personal Area Networks (WPAN). Starting from a headset cable replacement it has been extended to support flexible ad-hoc networks. The purpose of this thesis was to demonstrate and study Bluetooth technology and Bluetooth application development. Keywords—Bluetooth, WPAN, Ad-hoc network, Bluetooth application and technology, headset cable. I. INTRODUCTION Antenna matching is an important aspect of any RF system. A properly designed and matched antenna increases the operating distance of the wireless product. Well matched antennas can transmit more power from the radio – therefore transmit over longer distances. Likewise, a well matched antenna allows the maximum transfer of energy from the receiving antenna to the receiver front end. Thus, allowing better receive characteristics for the system. Antenna matching becomes critical as antennas are reduced in size and placed in small modules that can experience wide temperature ranges and potentially have foreign objects in proximity. This paper discusses one class of intermediate Q capacitors used for SMT antenna matching. II. BLUETOOTH ANTENNA Bluetooth Technology. Bluetooth is a wireless technology standard invented by Ericsson in 1994 for exchanging data over short distances using short-wavelength UHF radio waves (Range: 2.4 to 2.485 GHz) from fixed and mobile devices.. Because the typical Bluetooth radio is part of a mobile device, a Bluetooth device must be able to dynamically locate devices within the area. A Bluetooth device must also be able to determine what services are on the devices found. The Bluetooth specification separates discovery of devices and discovery of services into separate processes. In the device discovery process, the local Bluetooth device finds the other Bluetooth devices in the area. In the service discovery process, the Bluetooth device determines which services the other devices have running on them. In Bluetooth terms, device discovery is known as inquiry. When a Bluetooth device issues an inquiry, the other devices in the area respond to the inquiry requests depending on their discoverable mode. These devices respond with their Bluetooth address and class of device record. The Bluetooth address is a 6-byte unique identifier assigned to every Bluetooth device by the manufacturer. The class of device record describes the type of Bluetooth device and provides a general indication of the types of services available on the device. At the time of publication, the Bluetooth SIG had defined two type of inquiries: general and limited. A general inquiry is used to find all the Bluetooth devices in an area. A limited inquiry is used to find all devices in an area that are discoverable for only a limited length of time. A general inquiry is similar to asking all people in a room to say their names. A limited inquiry is similar to asking all people in a room to say their names only if they are accountants. Which devices respond to an inquiry request depends on the discoverable mode of the device. A Bluetooth device can be general, limited, or not discoverable. A general discoverable device responds only to general inquiries. Limited discoverable devices respond to general and limited inquiries. A device cannot respond to any inquiries if it is not discoverable. Any structure that is resonant at 2.45 GHz with bandwidth more than 100 MHz and efficiency >50% can be considered a Bluetooth antenna. Therefore, a countless variety of antennas can be used, and they are application-specific. Wire Monopole — This consists of a simple wire soldered at one end from which it is fed against a ground plane. It is trimmed to be resonant at 2.45 GHz and provides good performance and high efficiency. The disadvantage of this antenna is that it is not low profile because it projects above the PCB. PIFA — The Printed Inverted F Antenna is like a monopole printed on a PCB, but it has a ground point and feed point along the main resonant structure. Helix — Similar to the wire monopole, except that it is coiled around a central core (usually air) making the physical dimensions smaller. It provides excellent performance, but projects above the PCB. Ceramic — Surface mount dielectric antennas are the smallest types of antennas available, because they are printed on a high-dk ceramic slab, which makes the electric field concentrated allowing the antenna to be made small while keeping a high resonant frequency. III. USING THE TEMPLATE A. Survey for Bluetooth 2. SMT antenna matching This paper discusses one class of intermediate Q capacitors used 3. 6-byte unique identifier The format is a welldefined sequence of 32 hex digits grouped into chunks of 8-4-4-4-12. This gives us 2^128 or about 10^38 numbers. Bluetooth Low Energy is a proper name according to the Bluetooth Core Specification. It is written capitalized by the Bluetooth Specification. The same is true for the Mesh Profile (it is written capitalized throughout the Mesh Profile Specifications. 4. BOM B. Some Common Mistakes for Bluetooth The Problems include failing to pair, audio hiccups, and recurring dropped connections, The situation usually involves a Few Bluetooth devices – say a phone a smartwatch, and a car stereo, trying to get along. Sometimes the conflict is between a phone, a fitness tracker, and Bluetooth headphones. IV. D. Figures and Tables A brief list of the Bluetooth Antenna methods that need to be implemented is given in Table 1. Fig. 1. Name Brief Description Ad-hoc Network Composed of individual devices communicating with each other directly. It avoids interference from other wireless devices. It has lower power consumption. It is easily upgradable. It has range better than infrared communication. The Bluetooth is used for voice and data transfer. Bluetooth devices are available at very cheap cost. No line sight hence can connect through any obstacles. Free to use if the device is installed with Bluetooth. The technology is adopted in many products such as head set, in car system, printer, web cam, Gps system, Keyboard and mouse. V. REFERENCES [1] https://www.sciencedirect.com/topics/computerscience/bluetooth-radio - Ease of use for Bluetooth (activate) [2] https://www.avx.com/docs/techinfo/whitepapers/AVX-WhitepaperBluetooth-AntennaMatching.pdf - Bluetooth Antenna matching PDF. [3] http://www.ti.com/lit/an/snoa519b/snoa519b.pdf Introduction for Bluetooth Antenna [4] https://www.sciencedirect.com/science/article/pii/S157087051930126 X - Survey for Bluetooth Matching Impedance. (activate) [5] http://dreuarchive.cra.org/2009/Jaramillo/DREU/files/final_report.pdf - IEEE Reference example pdf [6] https://thewirecutter.com/blog/understanding-bluetooth-pairingproblems/ Some common problems/mistakes ‘bout Bluetooth Antenna [7] https://www.polytechnichub.com/advantages-disadvantagesbluetooth/ - Advantages and Disadvantages of Bluetooth Antenna Public Member Fuctions 1. ACKNOWLEDGMENT (RESULT) The are some important advantages of Bluetooth are given below, C. Backgroud forBluetooth Antenna Many applications are driven into small size modules for cost and ease of system integration. An example of this is automotive Bluetooth modules. In this case, the use of SMT chip antennas offers a very good solution to designers. SMT chip antennas take up minimal PCB area and offer reasonable performance across frequency. However, the use of chip antennas typically increases the BOM and assembly expense over PCB and wire antennas. Additionally, SMT antennas performance is very relative to the ground plane they are placed upon. Unlike PCB and wire antennas – they cannot be trimmed to accomplish tuning. Therefore, external components are required for tuning and impedance matching. The goal of impedance matching is to match the module’s output to the 50 ohm load of the antenna. Once this is accomplished most of the power from the RF source is delivered to the load in the transmit mode, and most energy is transferred from the antenna to the receiver front end in the receive mode. The exact circuit for matching an antenna and module will depend upon the antenna type, RF module used, ground plane, and system specifics etc. Regardless of the exact system details – inductors and capacitors will be used in a variety of configurations to accomplish the necessary impedance transformation to accomplish matching. An example of one type of matching network is shown below. To include all necessary parts for a functioning system as well as basc compotents and consumables. - Thoery and IEEE conference templates contain guidance text for composing and formatting conference papers. Please ensure that all template text is removed from your conference paper prior to submission to the conference. Failure to remove template text from your paper may result in your paper not being published. is composed of individual devices communicating with each other directly. We suggest that you use a text box to insert a graphic (which is ideally a 300 dpi TIFF or EPS file, with all fonts embedded) because, in an MSW document, this method is somewhat more stable than directly inserting a picture. To have non-visible rules on your frame, use the MSWord “Format” pull-down menu, select Text Box > Colors and Lines to choose No Fill and No Line.
