Polarization Reconfigurable Circular Patch

This work introduces a narrowband single-fed polarization reconfigurable microstrip antenna at S-band. The antenna is composed of a circular patch that is connected to a reconfigurable feeding network placed underneath it through vias. The feeding network is composed of a
$\boldsymbol{90^{\circ}}$
hybrid coupler connected to a single pole double throw (SPDT) absorptive RF switch. The antenna is able to change between left-hand and right-hand polarization states according to the switch condition. A prototype model is fabricated and tested where the simulated data agree with the measured ones. The acquired radiating characteristics show the antenna to perform with a reflection coefficient
$\boldsymbol{ < -15\text{dB}}$
, realized gain
$\boldsymbol{> 4\text{dBic}}$
, and an axial ratio of
$\boldsymbol{< 0.3\text{dB}}$
at the center frequency. The antenna forms a stack topology reducing its overall size to
$\boldsymbol{2\pi\ \mathrm{x}\ 25^{2}\text{mm}^{2}}$
for compact communication systems.