W-band MMIC amplifiers based on quarter micron gate-length InP HEMTs and coplanar waveguides

A family of one, two and three stage monolithic amplifiers on InP substrate for W-band applications are presented. The circuits are realized with lattice matched InAlAs-InGaAs-InP HEMTs with a gate-width of W/sub G/=2/spl times/40 /spl mu/m and T-gates with a gate-length of L/sub G/=0.25 /spl mu/m. Coplanar waveguides and lumped elements are used for the matching and biasing networks. The circuits are fully passivated and contain common ports for the gate and the drain bias. A gain of 5.5, 11 and 14.5 dB and an input and output matching better than -10 dB were achieved for the one, two and three stage amplifiers at 80 GHz, respectively. The measured results show a good scaling of the achieved gain between the one and the multiple stage amplifiers and a good correlation with the simulated results.