Theory and design of smart RF components using the novel FPMS technology

Abstract

The increasing demand for intelligent wireless communication systems has accelerated the development of reconfigurable microwave components capable of adapting their electromagnetic characteristics in real time. Modern applications, including phased-array antennas, satellite communications, radar systems, fifth-generation (5G) and emerging sixth-generation (6G) wireless networks, require compact, low-loss, and electronically reconfigurable microwave devices that can dynamically control the radiation characteristics of antennas. Conventional approaches generally rely on phased arrays with complex feeding networks or transmission-line-based phase shifters, which often suffer from increased circuit complexity, larger physical size, higher insertion loss, and significant power consumption. Consequently, there is a growing need for alternative reconfigurable technologies that simplify system architecture while maintaining high performance. This thesis investigates the concept of the Field Programmable Microwave Substrate (FPMS) as a new platform for realizing reconfigurable microwave components through dynamic control of the effective permittivity of the propagation medium. The research demonstrates two major applications of the FPMS concept. The first contribution presents a programmable artificial magnetic conductor (AMC) integrated with a single antenna element to achieve electronic beam steering without employing a conventional phased-array architecture. The proposed FPMS-AMC simultaneously functions as a reflective surface that suppresses backside radiation while dynamically controlling the reflection phase to steer the main beam. A beam steering range of approximately ±30° is achieved while maintaining a maximum realized gain of 7.2 dBi at 10 GHz. The fabricated prototype validates the proposed concept and demonstrates good agreement between simulated and measured results. The second contribution introduces a continuously tunable phase shifter based on a programmable dielectric waveguide realized using FPMS technology. Unlike conventional phase shifters that employ switched transmission lines, loaded-line networks, or reflection-type circuits, the proposed design controls the propagation constant by electrically tuning the effective permittivity of the dielectric guiding region. An analytical model based on guided-wave theory is developed for both homogeneous and non-homogeneous dielectric configurations. The analytical predictions are verified through full-wave simulations and experimental measurements. The fabricated prototype demonstrates a continuous phase tuning range of approximately 300° at 2.5 GHz with good agreement between theoretical, simulated, and measured results. Overall, this thesis establishes the FPMS as a versatile reconfigurable electromagnetic (EM) platform capable of controlling both radiation characteristics and guided-wave propagation through programmable dielectric properties. The proposed analytical framework, validated experimental results, and demonstrated antenna applications provide a foundation for future reconfigurable microwave and antenna systems requiring compact size, continuous tunability, and simplified beam steering architectures.