Power-Efficient $W$ -Band (92–98 GHz) Phased-Array Transmit and Receive Elements With Quadrature-Hybrid-Based Passive Phase Interpolator

This paper presents a power-efficient phased-array transmit and receive (T/R) channels adopting phase shifters (PSs) utilizing quadrature-hybrid-based power-domain phase interpolator. The W-band T/R channels are implemented in GlobalFoundries 0.13- $\mu \text{m}$ SiGe BiCMOS process (GF8XP) for large-scale phased-array applications. At 94 GHz, the proposed Rx channel achieves 137-dB $\cdot $ Hz dynamic range (DR) with 18-mW dc power consumption ( $P_{\text {diss}}$ ), one of the smallest $P_{\text {diss}}$ at W-band. The measured Rx channel gain is 17–23 dB with 5.8–6.6-dB noise figure (NF) over 92–98 GHz. The rms gain error and rms phase error in the Rx channel are less than 2 dB and 6°, respectively, at 92–100 GHz. The input $P_{-1\text {dB}}$ is −31 dBm at 94 GHz. The Tx channel produces 7.4-dBm saturated output power with 49.5-mW $P_{\mathrm{ diss}}$ at 94 GHz resulting in 11% of collector efficiency, one of the highest Tx channel efficiencies reported so far. The $P_{\mathrm{ diss}}$ at quiescent bias point of the Tx channel is 26 mW. The measured Tx channel gain is 7.5–12 dB and the rms gain error is $ 1.28 dB over 85–105 GHz. The measured rms phase error in the Tx channel is $ 1.5° at 94 GHz and remains lower than 8° when driving the Tx channel up to near the power saturation. The peak collector efficiency and PAE of the integrated class-AB power amplifier is 23.5% and 18.2%, respectively, at 94 GHz, one of the highest efficiency performances at W-band. The chip sizes of the Rx and Tx channels excluding I/O pads are $1.2 \times 0.55$ mm 2 and $1.4 \times 0.55$ mm 2 , respectively.