A 42 GHz Amplifier Designed Using Common-Gate Load Pull

A new technique is proposed for the design of linear and power amplifiers at mm-wave frequencies where load-pull of large transistor output cells is difficult. The technique transforms the load-pull data on a small, standard foundry transistor layout to a pair of common-gate contours for the intrinsic device; one gate-source and one gate-drain. These are then recombined as an intrinsic drain-source contour for a larger and arbitrary transistor layout. A driver amplifier for the ETSI 42 GHz point-to-point radio band has been designed using the proposed technique. The fabricated MMIC consumes 1.5 watts and has a gain of 25 dB, and OIP3 of 36 dBm, OIP5 of 28 dBm and P1dB of 23 dBm which is believed to be the best reported result to date.