A Linearly Polarized Patch Antenna With a Continuously Reconfigurable Polarization Plane

A linearly polarized (LP) wave with an arbitrary polarization plane is generated by combining left-handed circularly polarized (LHCP) and right-handed circularly polarized (RHCP) waves radiated from a dual-circularly polarized patch antenna. The polarization plane of the LP wave is continuously controlled by changing the phase difference between the LHCP and RHCP waves by using variable phase shifters composed of a quadrature hybrid and varactor diodes. Experimental results show that the polarization plane rotates continuously from -95° to 107° with a cross-polarization discrimination kept better than 22 dB in the boresight direction at 5.2 GHz.