Noise Figure Improvement in InP-Based HEMTs Using Wide Gate Head and Cavity Structure

The minimum noise figure (NF_min) at 94 GHz was improved effectively by employing a cavity structure in the interconnection process, even though a wide gate head was used in InP-based high-electron-mobility transistors (HEMTs). The wide gate head is effective in improving NF_min since gate resistance is reduced, while increased parasitic capacitance at a passivated gate affects the noise figure. Then, the parasitic capacitance was eliminated successfully by employing a cavity structure around the gate region. We measured an NF_min of 0.9 dB when the cavity structure was employed in the wide-gate-head HEMTs.