A High Aperture Efficiency and Wideband Transmitarray Antenna Using Novel Double C-Shaped Elements

A novel polarization rotation element (PRE) is employed to design a wideband transmitarray antenna (TA). The PRE comprises three metallic layers. The middle layer features double C-shaped patches, while the upper and bottom layers consist of two grating polarizers. By adjusting the opening sizes and directions of the double C-shaped patches, full phase coverage within -1 dB transmission magnitude can be achieved. Moreover, the polarization conversion ratio (PCR) is more than 97%, from 9.2 to 15.2 GHz. Based on the proposed PREs, a horn-fed TA with a 256 mm x 256 mm aperture area has been designed, fabricated and measured. The measured results of the TA show that the peak gain of 27.3 dBi and the aperture efficiency of 61.9% are achieved at 9.7 GHz. The maximum sidelobe level (SLL) and cross-polarization level at this frequency are -18.14 dB, and -37.36 dB, respectively. Furthermore, the 1 dB and 3 dB gain bandwidth of the TA is 33.9% and 46.9%, respectively. The measured results are in reasonable agreement with the simulated ones.