Cross Polarization Reduction of Line fed Circular Microstrip by Defected Ground Structure

This paper proposes a simple configuration of defected ground structure for suppressing the cross polarization in a line fed circular patch antenna. A circular patch antenna with symmetrical defects in ground plane is designed and simulated in X-band showing 18 dB suppression in cross-polarized fields in H-plane compared to circular patch without defect in ground plane. It is verified that the proposed method is effective in suppressing the cross polarization in the E plane as well without affecting the primary radiation. The defected ground structure, designed in this paper, does not change other antenna parameters like peak gain, input impedance, bandwidth. This design is suitable for satellite communication applications which require large cross polarization isolation. The design and simulation process is carried out by using AWR simulator.