Circularly Polarized VHF Turnstile Antenna System using Offset Inverted F antennas for AISAT-1 Payload Application

A circularly polarized antenna system is proposed for AMSAT-APRS digipeater which transmits and receives payload data at VHF band. This antenna system consists of asymmetrically placed four linearly polarized inverted F antennas which are supported by feed network and phase matched RF cables. These antennas are mounted along the circumference of stage-4 of PSLV at 0°, 70°, 180°, 290° planes. It provides omni-coverage with minimum gain of -10dBi and return loss better than 15dB.