A bandwidth-enhanced orthogonally polarized dual band reflectarray antenna

The design, and experimental validation of a single layer, transmit-receive reflectarray antenna (RA) to operate over a wide uplink and downlink frequency range of fixed satellite service is reported in the paper. The RA element is constructed using concentric circular patches with square slots etched on TLY 5 substrate backed by the metallic ground. A gradual increase in the radius of the rings offer the necessary 360 phase variation with reduced slope at uplink resonant frequency (14.25 GHz) and at downlink resonant frequency (11.8 GHz). Using the phase compensation cycles calculated for the 961 elements of the RA, an optimized distribution of the uplink and downlink elements is made on its square aperture (12.7 mm x 12.7 mm). A measured gain of 25 dBi and 26.5 dBi is obtained at 14.25 GHz and 11.8 GHz respectively. The 1 dB gain bandwidth is observed as 11 % between 13.75-14.50 GHz (Uplink) and 19 % in the 10.95 to 12.7 GHz (Downlink) range. The patterns obtained from the measurements indicate a good side lobe level of -14 dB and -13.5 dB at the uplink and downlink resonant frequencies. Similarly, a good discrimination between the orthogonal polarizations is measured at the two bands. Hence the proposed antenna with its enhanced radiation performances befits the transmission and reception of video and data in satellite communication.