A POLARIZATION RECONFIGURABLE MICROSTRIP ANTENNA EMPLOYING DUAL-PERTURBATION TECHNIQUE

摘要： This study presents a polarization recon?gurable antenna with frequency diversity function. The antenna incorporates a novel positive and negative perturbation technique to achieve di?erent polarization sense. A square shape slot is loaded on the ground plane to excite circular polarization by creating a negative perturbation. An L-shape segment is integrated to the patch using a switching diode. This segment creates a positive perturbation to eliminate the negative perturbation created by the defected ground slot, and the antenna excites linear polarization. Frequency diversity is achieved by exciting di?erent polarization senses at di?erent frequencies. A 3-dB axial ratio bandwidth of 1.41% is obtained for circular polarization radiation while the 10-dB impedance bandwidth during linear polarization is 1.8%. The antenna shows good radiation performances with high gain at both polarization states, and the performances are con?rmed experimentally.