Quarter wavelength parasitic stub loaded polarization reconfigurable patch antenna.

In this paper, a microstrip single feed circular radiating patch loaded with two parasitic stubs to achieve diversity for antenna polarization is presented. The primary antenna is a circular metallic patch with a rectangular slotted Defected Ground Structure (DGS) and it resonated at 5.5 GHz for Linear Polarization (LP). To achieve Left and Right Hand Circular Polarization (LHCP and RHCP) two-quarter wavelength metallic stubs are attached with a radiating patch through two PIN diodes. The antenna reconfigures its polarization states between LP, LHCP, and RHCP by diodes switching configurations. The proposed antenna is printed on a 0.8 mm thick RT/Duroid 5880 substrate and it provided satisfactory agreement between measured and simulated results. It has an impedance bandwidth of 5.23–5.75 GHz (9.45%) for S11 less than −10 dB and Axial Ratio Bandwidth (ARBW) for 3 dB is approximately 5.4%. [ABSTRACT FROM AUTHOR]