Circular Polarization Dual-Feed Array Antenna for X-Band Satellite Communication

A circular polarization dual-feed array antenna for X-band satellite is proposed. In this paper, sequential phased rotation principle applied for 2×2 sub-arrays and 4×4 array is introduced. A dual feeding network for single element is analyzed and designed in such a way that it can obtain 90 degree phase difference and 1:1 power ratio for each output port. The capacitive annular gaps are placed on inside of square driver patch for impedance matching. Consequently, X-band ranging from 8.04 to 8.4 GHz is covered completely and axial ratio is less than 2 dB. An 4×4 array antenna has a simulated gain of 13.76 dBi is achieved at 8.2 GHz. The whole antenna achieves a compact size and shows a great potential in satellite communication.