Circularly polarized electronically steerable parasitic array radiator antenna for satellite

This paper presents a circularly polarized electronically steerable parasitic array radiator (ESPAR) antenna. Its parasitic array is composed of a reconfigurable periodic structure. Using this novel structure, the radius of the ESPAR antenna has been significantly reduced. The driven element is a circular patch antenna, which connects to a 50 Ω RF source. The parasitic array is controlled by PIN diodes. There are no phase shifters employed for pattern steering. The proposed ESPAR antenna has a maximum gain of 6.2dBi; its elevation angle is tunable from 0 ° to 60 ° with axial ratio lower than 3dB and it is able to cover 360 ° in azimuth at an elevation angle of 45 ° with an axial ratio lower than 3 dB.