Design of a High-Gain Transmit-Reflect-Array Antenna for Bidirectional Beams Exhibiting Orthogonal Polarization Characteristics

A high-gain transmit-reflect-array (TRA) antenna with bidirectional beams and orthogonal polarization attributes is presented in this paper. The antenna features an arrow-shaped amplitude-phase modulated (APM) unit, which can switch between transmission and reflection characteristics by adjusting the angle of the arrow. Additionally, the polarization attributes of the transmitted and reflected electromagnetic waves are orthogonal. Utilizing this APM unit, a sparse array approach is employed to design the TRA antenna, integrating both transmitted and reflected units on the same phase-shifting surface to achieve bidirectional beams. The measured results align well with simulation outcomes. The transmitted beam is y-polarized while pointing at 0°, achieving a peak gain of 24.1 dBi with a relative 1-dB gain bandwidth of 16.2% at 30 GHz. On the other hand, the reflected beam is x-polarized while pointing at 170°, attaining a peak gain of 24.0 dBi with a relative 1-dB gain bandwidth of 13.1% at 30 GHz.