Implementation and Validation of Parasitic Stub Integrated Reconfigurable Polarization in Antennas

Abstract

This proposed work presents a single feed radiating patch loaded with two parasitic stubs to achieve antenna polarization diversity. The primary antenna is a circular/square metallic patch with a rectangular slotted Defected Ground Structure (DGS), and it resonated at 5.5 GHz with Linear Polarization (LP). The Circular Polarization (CP) is achieved through quarter wavelength parasitic metallic stubs attached with a radiating patch using two PIN diodes which reconfigure the antenna for left hand CP (LHCP) and right-hand CP (RHCP) performances. The antenna is reconfigured its polarization modes between LP, RHCP, and LHCP by utilizing diodes switching configurations. Two antennas, a circular and a corner truncated square patch with parasitic stubs, are investigated to validate the concept of Circular Polarization (CP) using a quarter wavelength stub, and corresponding results are presented. The proposed antennas are printed on an RT/Duroid 5880 dielectric with a thickness 0.8 mm, and it provided a satisfactory agreement between measured and calculated results. The circular and square-shaped antennas have impedance bandwidth of 5.23-5.75 GHz (9.45%) for S11 less than -10dB, and measured axial ratio bandwidth (ARBW) for 3dB is approximately 5.4%.