A four-port circular patch antenna for polarization modulation

Polarization modulation is a technique to modulate digital information using different polarization of the electromagnetic wave. The existing waveform based modulation techniques are well developed and start approaching to their performance limits. Polarization modulation provides a new modulation dimension for wireless communications and can further increase data throughput. A four-port circular patch antenna is presented and investigated for the implementation of polarization modulation. It has four ports, each excites radiation of a different polarization. A single pole four throw RF switch is used to switch between the ports depending on the information symbol to be transmitted. The antenna is studied numerically and it shows good performance.