Methodology of design of millimeter wave power amplifiers complying with 125°C electromigration design rules in advanced CMOS technology

Two millimeter-wave (mmw) Power Amplifiers (PAs) designed in a 65 nm CMOS process with 8-metal layers and transistor f_t/f_max of 160/200 GHz and complying with 125°C electromigration design rules are reported. The amplifiers are designed to first validate the passive and active millimeter-wave models and then study the MOS reliability at 60 GHz. In this way, the PAs design takes electromigration constraints at 125°C into account which implies limitations on MOS width and thus on the circuits performances. The PAs operate from a 1.2 V supply voltage. A power gain of 7.8 dB and 4.5 dB, an OCP_1dB of 9 dBm and 6 dBm with 12.2% and 12.3% PAE and a saturated output power of 12 dBm and 9 dBm at 60 GHz are measured respectively for the 2 stages and the 1 stage amplifiers. Excellent agreement between measurement and simulation results at small and large signals is observed.