An Effective Solution for Designing Wideband 3-layer D-band Transmitarrays in PCB Technology

In this contribution, the design and experimental validation of a fixed-beam transmitarray operating in the D-band (110–170 GHz) are presented. The proposed flat lens is suitable for standard PCB manufacturing and features three-layer unit cells achieving a 3-bit phase quantization. The cells leverage different coupling mechanisms among receiving and transmitting elements to cover a wide frequency band of 50 GHz (35.3%, 51 GHz) with low transmission loss and phase errors. A $40 \times 40$ broadside transmitarray has been optimized to attain a gain between 30 dBi and 33 dBi over a 30-GHz bandwidth when fed by a 10-dBi source. The measured −1-dB relative bandwidth of 11.7% outperforms state-of-the-art designs in D-band relying on more complex technologies.