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-μm SiGe BiCMOS technology for Q-band applications. The phased-array shows 12.5±1.5 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 ≤8.8° of RMS phase error and ≤1.2 dB of RMS gain error for all phase states at 30–50 GHz. The maximum saturated output power is - 2.5±1.5 dBm per channel at 42.5 GHz. The RMS gain variation and RMS phase mismatch between all 16 channels is ≤0.5 dB and ≤4.5°, respectively. The chip consumes 720 mA from a 5 V supply voltage and overall chip size is 2.6×3.2 mm
²
. 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.