An Efficient Dual-Band Orthogonally Polarized Transmitarray Design Using Three-Dipole Elements

A dual-band transmitarray is proposed for downlink/uplink frequencies (12.5/14.25 GHz) of Ku-band satellite communications. The basic building block for the dual-band transmitarray is a three-dipole element. Such two elements are interlaced in orthogonal polarization for each frequency band independently. This element overwhelms the basic phase restriction of a simple dipole element, and 360 degrees phase range can be achieved in both bands with a four-layer configuration. However, it is explored (theoretically and experimentally) that three layers are preferred to be used instead of four layers due to a compromise between the phase range and reflection loss. A high-gain three-layer dual-band orthogonally polarized transmitarray is designed successfully. The measured results match well with simulation results, and high gains of 31.0 and 31.8 dBi are achieved with aperture efficiencies of 45.0% and 41.3% at 12.5 and 14.25 GHz, respectively. It also achieves 1 dB gain bandwidths of 7.2% and 7.0% in both the downlink and uplink frequency bands, respectively.