A new polarization reconfigurable microstrip antenna for diversity array

A new reconfigurable circularly polarized square ring microstrip antenna is proposed. The circularly polarized antenna operating at its fundamental TM11 mode is fed by a semi-annular ring feed line through proximity coupling. A high isolation RF switch is used in the feeding network to change the polarization. With suitable biasing arrangement of the RF switch, the antenna is capable to radiate either Right-handed Circular Polarization (RHCP) or Left-handed Circular Polarization (LHCP). The antenna is fed by a single port. This simple and compact design is desirable for polarization diversity array. Both experimental and simulation results of the antenna are presented and discussed.