Reconfigurable Quad-polarization L-band Antenna

A low-cost L-band antenna with reconfigurable quad-polarization is presented. The antenna consists of four identical radiating elements. Each element comprises two stacked rectangular patches to achieve more than 10% bandwidth. Through proper phasing of the four elements, the antenna can realize two orthogonal linear polarizations and two circular polarizations. To demonstrate the concept, an antenna is realized using FR-4 substrate. The measured 10-dB input return loss bandwidth is 11%. And the measured 3-dB gain bandwidth is from 1.21 GHz to 1.36 GHz, with a maximum gain of 8.8 dBi for both linear polarization and circular polarization.