Mutual coupling between circularly polarized H-shaped patch antennas

This paper presents a study on mutual coupling between circularly polarized (CP) H-shaped patch antennas at 2.5 GHz. Two types of elements orientation for 2-by-2 sequential-rotated arrays have been studied. Based on the calculated results with a mutual coupling criterion of below -20 dB, we determined the possible shortest element spacing between elements without sacrificing the matching and CP performances. The results of mutual coupling and boresight gains between two orientations are examined and compared.