Design of a polarization reconfigurable and frequency tunable patch antenna system on a magnetic substrate

Abstract

Modern radio frequency (RF) and microwave components are continuously evolving to meet the demands of new wireless technologies. One such demand is the ability of these components to be agile and smart. Thus, the rationale for plethora of research in the field of reconfigurable RF components. In this work, a patch antenna system that can be tuned for its center frequency and reconfigured for its radiation characteristics is studied on a magnetic substrate namely yttriumiron-garnet (YIG). By integrating PIN diodes along the feed lines of the two antenna elements, one can achieve the above stated control of polarization reconfigurability in tandem with the use of YIG substrate for frequency tuning. The antenna elements are arranged in a manner that provides cross-polarization between them that helps to generate two different linear polarization (one for each antenna). At the same time, the feed line is designed to provide a 90 of phase difference between the antenna elements, thus resulting in a circular polarization when both the antennas are activated. The simulated results of the antenna show −14.15 𝑑𝐵 matching at 7.3 GHz with stable radiation performance for three different polarizations that is circular polarization, Linear polarization along x-axis and Linear polarization along y-axis. This is accomplished by toggling the PIN diodes as needed. Furthermore, the antenna system is magnetized in simulations to study its impedance and radiation response for all three polarizations. A tunability of 1 GHz is achieved using full-wave simulations which demonstrate a range of 14%. These initial results demonstrate the feasibility of using the proposed design concept in current and future wireless communication systems.