Cascode cell analysis for ultra-broadband GaAs MMIC component design applications

Analysis and comparison of MMIC cascode cells is presented. The cascode employs the WIN Foundry PP10-10 0.1μm gate length, 2 mil AlGaAs/InGaAs pHEMT process in common-source and common-gate configurations. On-wafer s-parameter measurements are performed in the frequency range of 0.045 GHz-110 GHz for cascode and device pull-out data. Comparison of measured data is made with s-parameter simulation data obtained using the WIN Process Design Kit (PDK) in common-source & common-gate device configurations and Electromagnetic (EM) simulated data for the passives surrounding the cascode devices. The comparison of simulated & measured s-parameters investigates a 3 dB difference in gain and differing return losses. This work highlights the need for high frequency empirical device models for cascode cells, in particular a common-gate device model extraction including higher frequency parasitics, for implementation in mm-wave cascode designs.