Simple Polarization-Reconfigurable Antenna With T-Shaped Feed

In this letter, a novel polarization-reconfigurable antenna with a T-shaped feed is proposed. This antenna mainly comprises a square patch, a T-shaped feed, two p-i-n diodes, two conductive pads with a via hole, and a square ring slot in a ground plane. The two p-i-n diodes and two conductive pads with a via hole are used to switch the polarization mode of the antenna. Each branch line of the T-shaped feed is connected to or disconnected from the ground plane through the conductive pads with a via hole by independently adjusting the bias states of the two p-i-n diodes. As a result, the proposed antenna exhibits either a right-hand circular polarization (CP) or a left-hand CP when only one of the two p-i-n diodes is in the ON state. On the other hand, the antenna exhibits a linear polarization (LP) property when the two p-i-n diodes are in the OFF state.