110 GHz amplifiers based on compact coplanar W-band receiver technology

Abstract

The potential of coplanar waveguide technology to build compact system modules is demonstrated by means of passive and active MMIC components. The realized passive structures comprise a Wilkinson combiner/divider and a capacitively loaded ultra miniature branch line coupler. Very good agreement between the measured and modelled data is achieved up to 120 GHz. A cascode MODFET small signal model working up to above 100 GHz has been developed for predictable MMIC design. Based on an accurate design database, a compact integrated amplifier utilizing cascode circuitry for application in the 100-120 GHz frequency band has been fabricated showing a measured maximum gain of 20 dB at 110 GHz. The gain is comparable to the result of a 2-stage amplifier fabricated using 0.1 /spl mu/m gate PHEMTs, while the chip size is reduced by more than 50%.