Slotted patch and truncated edge techniques on microstrip antenna for CP-SAR S-band data transmitter

The Circularly Polarized Synthetic Aperture Radar (CP-SAR) uses Circular Polarization radio wave to transmit the Radar signal. With this polarization, the power consumption of CP-SAR is lower than common Synthetic Aperture Radar (SAR). Therefore, CP-SAR can be placed in microsatellite. Low power data transmitter also required in CP-SAR system, so circular polarization can also be used in the transmitter system. Circular polarization radio wave is produced by circularly polarized antenna. In this paper, slotted patch and truncated edge techniques to design circularly polarized microstrip antenna are evaluated. The results show that both techniques have similar performance. But, truncating the patch causes a further frequency response shift than adding slot to patch, so truncated edge technique is more difficult to design than slotted patch technique.