A Novel Reconfigurable Polarization Dual band Patch Antenna for WLAN and WiMAX Systems
This paper presents a novel dual band annular patch antenna with functional microstrip circuit module to reconfigure the polarized modes of the antenna. The proposed antenna consists of two bonded FR4 print circuit boards and is excited at WLAN band and WiMAX band by this functional circuit module. This module includes two branches of microstrip lines, two PIN diodes and a DC bias circuit. Two PIN diodes are placed on the two microstrip lines. The polarization of the antenna can be simply shifted back and forth between RHCP and LHCP by modifying the modes of PIN diode. Simulation and experimental results have shown a good bandwidth of axial ratio and antenna gain in circularly polarized states.