Broadband circularly polarized annular ring array antenna for wireless communications

Future mobile communication systems are based on digitally beam formed multibeam phased array systems. The multibeams are generated and scanned using electronic scanning. The broadband circularly polarized antennas are important element in this communication structure. This paper presents implementation and experimental evaluation of a 2times2 array antenna using annular ring patch antenna at S-band. The achieved directivity gain is 9 dBi over frequency of 2.1-2.7 GHz. The input 2:1 VSWR is measured over frequency range of 1 GHz