A High-Efficiency Dual-Band Dual-Circularly Polarized Transmit-Reflect-Array Antenna

A dual-band dual-circularly polarized (CP) transmit-reflect-array (TRA) antenna with high efficiency is proposed. Novel TRA cells possessing x-polarized transmission and y-polarized reflection characteristics are designed for achieving equal dual-CP radiation amplitudes at both transmission and reflection sides. The phases of transmission and reflection CP waves can be modulated separately by adjusting the x-polarized transmission, y-polarized reflection phase-delay line lengths, and the cell rotation angles. Under the excitation of CP incident waves, the designed TRA antenna generates eight CP beams, i.e., two K-band dual-CP transmission beams, two K-band dual-CP reflection beams, two Ka-band dual-CP transmission beams, and two Ka-band dual-CP reflection beams. The measured peak gain values are about 24 dBic and 27 dBic at K-band and Ka-band, respectively, for the demonstrated TRA antenna.