A 77 GHz Power Amplifier for Low Cost Radar Transmitters in a 55-nm CMOS Technology

A 77 GHz power amplifier (PA) fabricated in a low cost, low power 55-nm CMOS process for mm-wave radar transmitters is presented. The PA design is based on transformer-coupled topology to achieve compact size and high efficiency. The fabricated PA has a 26.5 dB peak gain with 3 dB gain bandwidth of 9 GHz (72-81 GHz). The PA has more than +11 dBm saturated output power (Psat) within the frequency range of 76-81GHz, with maximum Psat of +12 dBm at 78 GHz. From a 1.2 V supply, the PA achieved maximum power added efficiency (PAE) of 14%. Return losses at the input and output ports are less than -10 dB across the 70-90 GHz band. The fabricated PA occupies a compact size of 0.146 mm(2) silicon die.