Performance Comparison of Large Reflect Array Antenna With and Without faceted for SAR System

This paper presents the performance comparison of a 1.2 m large reflectarray (RFA) antenna with and without faceted for modern Synthetic Aperture Radar (SAR) application. In the absence of faceting in the RFA, it faces the issue of narrow bandwidth due to the small frequency operating of unit-cell and spatial path delay. The RFA geometry is designed by faceting the phase-compensating surface into single and double-axis configurations that provide true-time delay and improve spatial bandwidth. The phase distribution across the RFA surface and variation in the gain with frequency are computed using a PMOM method with the help of TICRA software. The results show that single and double-faceted RFAs improve the volume reduction by about 1/3 and 1/7 part of the overall volume of flat RFA. However, it reduces the gain. The proposed RFA contains a simple membrane-based design, hence containing approximately 1 Kg weight of standard parabolic reflector. The simulated results showed that single-axis faceted RFA achieves 39dB gain with ±0.5 dB variation in an improvement for the desired band. On the other hand, further improvement in double-axis faceted can improve the gain and significantly reduce the overall volume compared to a similar type of performance of parabolic reflector.