Date of Award

7-5-2018

Document Type

Thesis

Publisher

Santa Clara : Santa Clara University, 2018.

Degree Name

Master of Science (MS)

Department

Electrical Engineering

First Advisor

Ramesh Abhari

Abstract

As the lower range of radio frequency spectrum become more cluttered and the demand for faster data rates and greater bandwidth grows, next generation wireless technology is pushed to innovate and provide needed resources. Major technology companies such as Samsung, intel, Qualcomm Inc. and Google have been investing at millimeter-wave band frequencies to address this imminent need. The fifth generation of telecommunication technology could be perceived as a paradigm shift in the way we see and think about wireless communication. This next generation technology is intended to enable other up and coming industries and services such as internet of things (IOT), telemedicine and wearable devices. Antennas are the critical component in realizing any of the wireless systems in these emerging applications.

This thesis investigates design and simulation of 60 GHz microstrip patch antennas, in single and array arrangements. A few single patch antennas and 2x2 patch arrays were designed to operate at 60 GHz. The needed feed network for the studied antennas were also developed using microwave design techniques and transmission line theory followed by fullwave simulations to achieve matching at the excitation ports. First, a cavity-backed patch antenna is designed and optimized to maintain and improve the operational characteristics of a single radiating element. Next, via-fence strategy used for implementation of cavity was employed in array design. Extensive fullwave simulations and design trials revealed that at 60GHz, due to comparable dimensions of the microstrip feed network with those of the radiating elements, the overall antenna system radiation performance is impacted.

Hence, a second feed strategy using coaxial probe is utilized for new design iterations of single microstrip patch and 2x2 patch array. For these final designs the feed is via the vertical mount coaxial cable with center pin extended through the antenna substrate. This eliminated the need for a lengthy microstrip transmission line feed and reduced the amount of impedance fluctuations. Cavity backing strategy and via fencing were also included and optimized for these designs to optimize the antenna performance. It was concluded that cavity backing is the most practical approach for antenna system design at 60GHz which was able to improve the front to back lobe ratio of the patch antenna. This feature is very important in applications requiring confinement of radiation in only half space and directing it away from the user such as in health monitoring devices.

Finally, the fabrication process is discussed in detail which involves exporting the design layout from an electromagnetic field solver to another CAD tool to generate fabrication files and define the different components and layers. The connectors and launch pins needed for prototyping have been identified for future fabrication and testing.

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