Study, design and fabrication of a two-dimension beam scanning antenna in package

Abstract

Various emerging high data-rate applications such as ultra-high definition video streaming and wireless personal area networks have made the transition to the next generation communication systems at mmWave frequencies inevitable. Moreover, the antenna in package has been proved to be a suitable solution for a compact and efficient antenna system platform at this frequency range. Due to smaller wavelengths and aperture illumination at this frequency range, these antennas tend to have a limited radiation gain which consequently results into a limited connection range. To compensate, a high gain array antenna structure with beam steering capability is inevitable. Moreover, current developed mmWave frequency scanning antennas suffer from some shortcomings such as using active phase shifters, narrow impedance bandwidth, limited scanning range, lack of circular polarization, one dimensional beam steering, neglected electromagnetic interference, and non-efficient inter-layer interconnects. In view of these issues, the initial objective of this thesis is to study different antenna packaging methods as well as the recent developments in mmWave frequency and scanning antenna structures in order to design and produce a performant system. Consequently, a new design for a wideband circularly polarized frequency scanning periodic leaky-wave antenna has been proposed and tested which features a wide seamless scanning range of about 95° including the broadside and a fractional -10 dB impedance bandwidth of about 47%. Moreover, an accurate empirical model is developed for this antenna, as well as optimization methods to minimize the side lobe level and the axial ratio. In order to integrate band-pass filtering capability, a modified version of this antenna is also developed and tested in the scope of this research. With the goal of integrating band-pass filtering capability into the inter-layer transitions, new types of broadside coupled multi-layer filters have been designed and tested. With a fractional bandwidth of about 40% at the center frequency of 25 GHz, these filters are compact, tunable, and have a simple structure that makes them suitable candidates for replacing via interconnects in multi-layer antenna in package configurations. Finally, the antenna is combined as a linear phased array structure with a Rotman lens beamformer in a multi-layer structure to perform beam scanning in two dimensions. This system is designed and fabricated at 25 GHz and can steer the radiation beam in both E (90º) and H (60º) planes without any active phase shifter. The beamforming performance is preserved in a wideband frequency range from 20 to 30 GH and the undesired signals out of this band are attenuated using the integrated band pass filters.

Date	20 Dec 2017
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Dominic Deslandes (Supervisor)