W-band cascode amplifier modules for passive imaging applications

W-band amplifier modules with high gain and large bandwidth have been developed for passive imaging applications, With three cascaded waveguide modules, an average small-signal gain of 60 dB and a /spl plusmn/3 dB bandwidth of 15 GHz was achieved centered around 93 GHz. The assembled three-stage amplifier monolithic microwave integrated circuits are realized in coplanar technology for compact size and low cost. Cascode devices, based on a 0.15 μm AlGaAs/lnGaAs/GaAs pseudomorphic high electron mobility transistor technology allow for individual gain control of the stages by varying the second gate voltage.