A New Silicon-Based Dielectric Waveguide Technology for Millimeter-Wave/Terahertz Devices and Integrated Systems

Abstract

In recent decades, the millimeter-Wave (mmWave)/THz band has attracted great attention in the research community. The Terahertz frequency band runs from approximately 300 GHz to 3 THz, an incredible 2700 GHz of bandwidth. The Terahertz frequency range has traditionally been considered as the RF "no man's land", between electronic and optical technologies. Many efforts have been made to extend existing active and passive devices to take advantage of these higher frequencies. The development of a universal technology for integrating various functionalities in the THz region is the ultimate goal of many researchers. The primary focus of this research is to develop a novel silicon waveguide-based technology for implementing various structures and devices in the mmWave and THz range of frequencies. The structures introduced in this study are designed based on High Resistivity Silicon (HRS). Two technologies are developed and investigated at the Centre for Intelligent Antenna and Radio Systems (CIARS): Silicon-On-Glass (SOG) and Silicon Image Guide (SIG) technologies. The proposed technologies provide a low-cost, highly efficient, and integratable platform for realization a variety of mmWave/THz systems suitable for various applications such as sensing, communication, and imaging. A comprehensive study is conducted for functionality and error analysis of the proposed technologies. Also, a vast range of passive structures such as bends, dividers, and couplers are designed, fabricated and successfully tested with desired performance at the mmWave range of frequencies. Additionally, three types of dielectric waveguide antennas are designed and optimized: parasitic tapered antenna, groove grating antenna, and strip grating antenna. Another focus of this thesis is to investigate the behavior of resonance structures, operating based on Whispering Gallery Modes (WGMs). The WG mode is a special type of high order mode of a circular shaped resonator, and offers very unique properties, which make it very suitable for sensing applications. In this research, an efficient algorithm is developed for analyzing the WGM resonators. Then, the proposed HRS platforms are used for implementing various WGM resonance configurations. The introduced WGM structures are employed for two major applications: DNA sensing and resonance tuning. The results for DNA testing are quite impressive in being able to distinguish between different kinds of DNA. To demonstrate the usefulness of the developed HRS structures, a number of complex systems including, a Butler matrix network, a finger-shaped phase shifter, and tunable WGM resonance structures are designed, optimized, and realized in this report. As part of this research, a novel Microwave-Photonic idea is proposed for sensing purposes. The core of the system is based on the WGM resonance structures implemented on the HRS platforms. The proposed system is tested and promising results are achieved.