A four-element phased-array front-end receiver based on 4-bit RF phase shifters is demonstrated in a standard 0.18-mum SiGe BiCMOS technology for Q-band (30-50 GHz) satellite communications and radar applications. The phased-array receiver uses a corporate-feed approach with on-chip Wilkinson power combiners, and shows a power gain of 10.4 dB with an IIP3 of -13.8 dBm per element at 38.5 GHz and a 3-dB gain bandwidth of 32.8-44 GHz. The rms gain and phase errors are les1.2 dB and les8.7deg for all 4-bit phase states at 30-50 GHz. The beamformer also results in les0.4 dB of rms gain mismatch and les2deg of rms phase mismatch between the four channels. The channel-to-channel isolation is better than -35 dB at 30-50 GHz. The chip consumes 118 mA from a 5-V supply voltage and overall chip size is 1.4times1.7 mm2 including all pads and CMOS control electronics.