Common-Gate Load-Pull With Q-Band Application Simon J. Mahon, Senior Member , IEEE, Alan C. Y oung, Member , IEEE, and Anthony E. Parker , Senior Member , IEEE

Abstract

A new technique is proposed for the design of linear power ampli fiers at millimeter-wave frequencies where load-pull of large transistor output cells is dif ficult. The technique trans- forms the load-pull data on a small, standard foundry transistor layout to a pair of common-gate conto urs for the intrinsic device; one source–gate and one drain–gat e. These are recombined as an intrinsic drain–source contour for a larger and arbitrary transistor layout. A Q-band driver ampli fier for the ETSI 42-GHz point-to- point radio band has been designed using the proposed te chnique. The fabricated MMIC consumes 1 W and has a gain of 21 dB, with OIP3 of 35 dBm, OIP5 of 28 dBm and P1 dB of 23 dBm. The PAE is approximately 19%. The OIP3 to P1 dB and OIP3 to dc po wer ratios are believed to be the best reported to date.