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.