Several Effective Methods on Reducing Cross-Polarization of a Patch Antenna

Several methods are proposed to reduce the cross-polarization of a patch antenna by adding different additional structures. The first is to add an independent shorting pin on the line where the feed point is located. The other is to add a metal block of a specific height at a certain distance from the radiating edge with a stronger electric field of the patch; Finally, the two methods are combined to obtain even higher polarization purity. The above methods all aim to alleviate the asymmetry of the reversed magnetic currents of the fringing field when patch operates at the fundamental mode. The combined structure shows the suppression of the cross-polarization reaches to the level of −35.5 dB which is 26.6 dB lower than that of the traditional patch antenna. The simulated results verify the effectiveness of these methods.