A polarization-rotation AMC-based low-profile transmitarray antenna

A novel low-profile transmit-array (TA) is proposed by using multi-folded quasi-optic trace principle. The proposed TA unit cell would reflect the incident wave of x-polarization as a ground and transmit the incident wave of y-polarization with arbitrary phase shift in the operating frequency band. A broadband polarization rotation reflection surface based on artificial magnetic conductor (PRAMC) with small phase difference in wide range of incidence angle is applied to transform the polarization of incident wave. A TA antenna is studied, where the distances between the source and the TA is reduced to 1/3 of the focal length, which is much less than that of the conventional TA antennas. The simulated results show that the proposed TA antennas can achieve −1 dB gain drop bandwidth of 5% and cross-polarization level of less than −30 dB, and the aperture efficiencies can achieve 46%.