Broadband CP Microstrip Antenna with Higher Gain at Low Elevation for Satellite Communication

Abstract

In this paper, a broadband circularly polarized microstrip antenna with higher gain at low elevation is proposed for satellite communication systems. The antenna uses a Wilkinson power divider with 90° phase difference to feed a pair of orthogonally placed H-shaped slots to achieve broadband circular polarization. By loading a partially enclosed folded conducting wall which is contact with the ground plane and perpendicular to the dielectric substrate of microstrip antenna, broad beamwidth is achieved, thereby improving the gain at low elevation. The proposed antenna is fabricated and measured. The measurement results show that the gain of the antenna with the folded conducting wall at 20° elevation is at least 4.47dBi higher than the antenna without the folded conducting wall at the central frequency. The impedance bandwidth for |S11|< -10dB is 34.4%(1.76-2.52GHz).