A 40-GHz Power Amplifier With Output Power of 15.2 dBm in 65-nm CMOS

A millimeter wave (mm-Wave) power amplifier (PA) based on transformer matching network is presented in this paper. Two-stage common source (CS) differential structure PA is proposed which adopts cross-coupling capacitors to improve the stability and gain of the circuit, transformers are designed to simplify the design of impedance matching networks. Output matching is designed as a strongly coupled transformer to achieve low insertion loss, high output power and high efficiency, while the input and inter matching network is designed with low K (coupling coefficient) transformer to achieve better bandwidth. Designed and implemented in 65-nm CMOS technology with 1-V supply, the prototype delivers a saturated output power (Psat) of 15.2 dBm at 40 GHz, the maximum small-signal gain is 16.9 dB, and output IdB compression power (OPldB) is 12.41dBm with its corresponding power added efficiency (PAE) is 17.65%. The chip size is only 0.05 mm2 excluding all DC pads.