A Q-band (40–45 GHz) 16-element phased-array transmitter in 0.18-μm SiGe BiCMOS technology

A 16-element phased-array transmitter based on 4-bit RF phase shifters is designed in 0.18-mum SiGe BiCMOS technology for Q-band applications. The phased-array shows 12.5plusmn1.5 dB of power gain per channel at 42.5 GHz for all phase states and the 3-dB gain bandwidth is 40-45.6 GHz. The input and output return loss is less than -10 dB at 37.5-50 GHz. The transmitter also results in les8.8deg of RMS phase error and les1.2 dB of RMS gain error for all phase states at 30-50 GHz. The maximum saturated output power is -2.5plusmn1.5 dBm per channel at 42.5 GHz. The RMS gain variation and RMS phase mismatch between all 16 channels is les0.5 dB and les4.5deg, respectively. The chip consumes 720 mA from a 5 V supply voltage and overall chip size is 2.6times3.2 mm². To our knowledge, this is the first implementation of a 16-element phased array on a silicon chip with the RF phase shifting architecture at any frequency.