A High-Efficiency Transmit–Reflect Array With Independent Beam Control

This communication presents a novel dual-functional transmit–reflect array (TRA) antenna that allows for independent control of transmission and reflection beams. The TRA antenna operates as a transmitarray (TA) with polarization conversion at 17 GHz, converting <inline-formula> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula>-polarized incident waves into <inline-formula> <tex-math notation="LaTeX">$y$ </tex-math></inline-formula>-polarized transmissions while providing a full 360° phase shift range. In addition, it functions as a reflectarray (RA) at 33 GHz, preserving the <inline-formula> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula>-polarization properties with full 360° phase coverage. Importantly, the element response in the reflection mode is independent of that in the transmission mode, which is achieved through a dual-band decoupling optimization strategy. Furthermore, the proposed element has a simple triple-layer structure without air gaps or metallic vias, exhibiting enhanced efficiency and reduced fabrication cost. To validate the design concept, a TRA prototype with a diameter of 264 mm was fabricated and measured. The TA mode achieves a peak gain of 30.91 dBi (with an aperture efficiency of 56.9%) at 17.0 GHz, while the RA mode achieves a peak gain of 35.79 dBi (with an aperture efficiency of 47.5%) at 32.9 GHz. This dual-band, dual-mode TRA antenna enables new possibilities for advanced wireless communication and radar applications.