A linear 60 GHz 65 nm-CMOS power amplifier realization and characterization for OFDM signal
Résumé
A millimeter-wave Power Amplifier (PA) based on a 65nm CMOS technology from STMicroelec- tronics has been designed. The targeted feature is the unlicensed band around 60 GHz suitable for wireless per- sonal area network application (WPAN). To optimize the linearity, the PA is designed under class A biasing to have an output compression point (OCP 1 ) close to its saturated Power (P sat ). S-parameters and large signal measurement results are demonstrated and compared with electromag- netic simulations. The PA offers a P sat of 8.3 dBm, an OCP 1 of 6 dBm and a gain of 6.7 dB. The die area is 0.29 mm 2 with pads. Considering those results, one-tone simulations are not sufficient to characterize the linearity performances of the PA in its real conditions of use. Consequently, two-tone simulations are firstly performed. After, linearity figures of merit (FoM) are discussed applying an orthogonal frequency-division multiplexing (OFDM) modulated signal. The PA offers an adjacent channel power ratio (ACPR) of 15 dB and an error vector magnitude (EVM) of 20% at PA compression operating mode.