Micro Electro Mechanical Systems Integrated Frequency Reconfigurable Antennas for Public Safety Applications

This thesis work builds on the concept of reconfiguring the antenna properties (frequency, polarization, radiation pattern) using Radio Frequency (RF) Micro Electro Mechanical Systems (MEMS). This is a part of the overall research performed at the RF Micro/Nano Electro Mechanical Systems (uNeMS) Laboratory at Utah State University, which includes design, microfabrication, test, and characterization of uNeMS integrated cognitive wireless communication systems (Appendix A). In the first step, a compact and broadband Planar Inverted F Antenna (PIFA) is designed with a goal to accommodate reconfigurability at a later stage. Then, a Frequency Reconfigurable Antenna (FRA) is designed using MEMS switches to switch between the Public Safety (PS) bands, 152-162 MHz and 406-512 MHz, while maintaining the integrity of radiation pattern for each band. Finally, robust mechanical designs of the RF MEMS switches accompanied by different analyses have been performed. These analyses are instrumental in obtaining high yield, reliable, robust microfabrication processes including thin film metal deposition and patterning

Reconfigurable Antennas for Public Safety and Wireless Gigabit Alliance Applications

The main goal of this research is to develop a new type of antenna, called reconfigurable antenna, which can replace multiple antennas required to enhance the effectiveness of a robust communication system. A recongurable antenna integrated with switching elements can dynamically change its properties, namely, frequency of operation, radiation pattern (the three-dimensional coverage of antenna), and polarization (the electrical orientation of the antenna). Depending on the requirement, a single antenna can function as multiple an- tennas, therefore, the name Multi-functional Recongurable Antenna (MRA). United States (US) Public Safety (PS) responders (police, re-ghters, emergency medical services, etc.) can effectively respond to human-made or natural catastrophies if they are equipped with robust communication systems supported by MRA. Wireless implementations of computer accessories (wireless HDMI, wireless storage to external hard-drive, etc.) that require high speed data communication are supported by 60 GHz communications. Equipping these devices with MRA could further increase the speed of communication, thereby resulting in a robust communication. In this work, pin-diodes and Micro Electro Mechanical Switches (MEMS) are integrated on the MRAs to reconfigure (dynamically change) its properties namely frequency and radiation pattern. An MRA capable of operating over 220, 470, 800, 4900 MHz PS bands is designed, manufactured, tested, and characterized. Another MRA capable of changing its radiation pattern over 4.94-4.99 GHz band is designed, manufactured, tested, and characterized. The design of radiation pattern recongurable MRA and Multi-functional Reconfigurable Antenna Array (MRAA) for 60 GHz communication is also accomplished. The MRAA is designed in order to enhance the MRA\u27s capability to receive or transmit more power

Air bag safety systems update (1993-1996)

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RF MEMS reconfigurable two-band antenna

Peer ReviewedPostprint (published version

RF MEMS reconfigurable two-band antenna

Peer Reviewe

An adaptable mathematical model for integrated navigation systems

SIGLEAvailable from British Library Document Supply Centre- DSC:DX179108 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Parasitic layer-based reconfigurable antenna design by multi-objective optimization

A parasitic layer-based multifunctional reconfigurable antenna (MRA) design based on multi-objective genetic algorithm optimization used in conjunction with full-wave EM analysis is presented. TheMRA is capable of steering its beam into three different directions simultaneously with polarization reconfigurability having six different modes of operation. The MRA consists of a driven microstrip-fed patch element and a reconfigurable parasitic layer, and is designed to be compatible with IEEE-802.11 WLAN standards (5–6 GHz range). The parasitic layer is placed on top of the driven patch. The upper surface of the parasitic layer has a grid of 5 5 electrically small rectangular-shaped metallic pixels, i.e., reconfigurable parasitic pixel surface. The EM energy from the driven patch element couples to the reconfigurable parasitic pixel surface by mutual coupling. The adjacent pixels are connected/disconnected by means of switching, thereby changing the geometry of pixel surface, which in turn changes the current distribution over the parasitic layer, results in the desired mode of operation in beam direction and polarization. A prototype of the designed MRA has been fabricated on quartz substrate. The results from simulations and measurements agree well indicating 8 dB gain in all modes of operation.Peer Reviewe

Three-dimensional microfabricated broadband patch antenna for wiGig applications

The design, microfabrication, and characterization of a broadband patch antenna capable of covering the entire IEEE 802.11ad (WiGig) frequency band (57-66 GHz) are presented in this letter. A conductor-backed (CB) coplanar waveguide (CPW)-fed loop slot couples the energy to the patch antenna, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate (epsilon(r) = 3.9, tan delta = 0.0002 at 60 GHz), on top of which an SU-8-based three-dimensional (3-D) structure with air cavities is microfabricated. The patch metallization is deposited on top of this 3-D structure. While the main role of the structure made out of SU-8 material is to provide a mechanical support for the patch metallization, the antenna takes advantage of the air cavities underneath, thus resulting in an antenna substrate with a very low loss. This, in turn, improves the overall antenna performances. The simulated and measured impedance characteristics agree well, showing similar to 15% bandwidth. Also, the radiation pattern results demonstrate the integrity of radiation pattern with reasonably constant gain values (average similar to 6.4 dB) in the broadside direction over the entire WiGig band.Peer ReviewedPostprint (published version

Three-dimensional microfabricated broadband patch antenna for wiGig applications

The design, microfabrication, and characterization of a broadband patch antenna capable of covering the entire IEEE 802.11ad (WiGig) frequency band (57-66 GHz) are presented in this letter. A conductor-backed (CB) coplanar waveguide (CPW)-fed loop slot couples the energy to the patch antenna, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate (epsilon(r) = 3.9, tan delta = 0.0002 at 60 GHz), on top of which an SU-8-based three-dimensional (3-D) structure with air cavities is microfabricated. The patch metallization is deposited on top of this 3-D structure. While the main role of the structure made out of SU-8 material is to provide a mechanical support for the patch metallization, the antenna takes advantage of the air cavities underneath, thus resulting in an antenna substrate with a very low loss. This, in turn, improves the overall antenna performances. The simulated and measured impedance characteristics agree well, showing similar to 15% bandwidth. Also, the radiation pattern results demonstrate the integrity of radiation pattern with reasonably constant gain values (average similar to 6.4 dB) in the broadside direction over the entire WiGig band.Peer Reviewe