INVESTIGATIONS ON MULTI-MODE RESONATORS FOR COMMUNICATION AND SENSING APPLICATIONS

Abstract

Radio frequency (RF) to terahertz (THz) electromagnetic (EM) waves enable a new vista for many applications such as wireless communication, sensing, food processing and material processing, etc. These high-frequency EM waves' wireless communication capability enables many exciting features and are being used everywhere, from defense to day-to-day communication. Advanced wireless communication system supports many applications on the same platform. Different channel modeling, modulation schemes, front-end architectures, and new semiconductor material technologies are being explored to enhance wireless communication system performance and user experience. In addition, to reduce hardware complexity and to achieve higher energy efficiency, techniques are explored to reduce the footprint area, power consumption, and loss in the system components. Further, due to non-ionizing and non-destructive nature, microwave-to-THz EM waves have gained significant attention in the direction of non-intrusive and real-time sensing. Owing to these characteristics, microwave-to-THz sensors are currently being used in various industrial and biomedical applications such as in detecting the adulteration in food and oils, and monitoring of the blood glucose, blood pressure, temperature, and humidity, etc. In order to realize many of the wireless transceiver front-end components and sensing structures, resonator is used as the key design element. It stores electromagnetic energy in terms of the electric and magnetic fields. Recently, multimode resonators have attracted much of the attention. Like the name, the multi-mode resonator supports more than one electromagnetic modes in the single structural design. The reported work in this thesis investigates the planar multi-mode resonating structures to realize compact bandpass filters (BPFs) and resonant sensors.