A Q-band Phased-Array Transmit Beamformer in 45 nm CMOS SOI for SATCOM

This paper presents a high-gain, high-efficiency phased-array transmit (TX) beamformer chip in a 45-nm RFSOI process for SATCOM phased-array. The beamformer employing a active vector modulated phase shifter and a three-stacked-FETs power amplifier with neutralization, result in high linearity and low power consumption. The measured gain is 25.2 to 28.6 dB of 17.1-18.5 dBm and satuated output power $\left(P_{s a t}\right)$ from 19.5-20.4 dBm, repectively. A peak power-added efficiency (PAE) of 24.9% at 39.5 GHz is achieved. The measured root-mean squared (RMS) gain error and phase error are below 0.45 dB and 3 degrees,respectively. The beamformer occupies $1.4 \mathrm{~mm}^{2}$ including pads and consumes 225 mW DC power. This work achieves state-of-the-art linearity and efficiency for Q-band SATCOM transmit (TX) phased-array systems.