W-band cascode amplifier modules for passive imaging applications

W-band amplifier modules with high gain and large bandwidth have been devel oped for passive imaging applications. With three cascaded waveguide module s, an average small-signal gain of 60 dB and a +/-3 dB bandwidth of 15 GHz was achieved centered around 94 GHz, The assembled three-stage amplifier mo nolithic microwave integrated circuits are realized in coplanar technology for compact size and low cost. Cascode devices, based on a 0.15 mu m AlGaAs /InGaAs/GaAs pseudomorphic high electron mobility transistor technology, al low for individual gain control of the stages by varying the second gate vo ltage.