A 4-channel 24–27 GHz CMOS differential phased-array receiver

The paper presents a 24-27 GHz 4-channel CMOS differential phased array receiver front-end with integrated baluns, ESD protection and VGAs. The differential implementation of the phased array significantly reduces the substrate coupling effects. The measured array performance shows an input and output match of < -10 dB, 12-15 dB gain, 7.8-9.5 dB NF, an IIP3 of -9 to -12 dBm, an input P_1dB of -19 to -22 dBm, and a 4-bit phase control with an rms gain and phase errors of < 0.35 dB and < 6deg, respectively, all at 24-27 GHz. The measured rms gain and phase errors due to on-chip coupling effects are < 0.25 dB and < 2deg at 20-30 GHz. The chip consumes 155 mA from a 1.5 V supply with an area of 4 mm² and can operate over a 3 GHz instantaneous bandwidth (limited by the gain response).