Power-amplifier modules covering 70-113 GHz using MMICs

A set of W-band power amplifier (PA) modules using monolithic microwave int egrated circuits (MMICs) have been developed for the local oscillators of t he far-infrared and sub-millimeter telescope (FIRST), The MMIC PA chips inc lude three driver and three PAs, designed using microstrip lines, and anoth er two smaller driver amplifiers using coplanar waveguides, covering the en tire W-band, The highest frequency PA, which covers 100-113 GHz, has a peak power of greater than 250 mW (25 dBm) at 105 GHz, which is the best output power performance for a monolithic amplifier above 100 GHz to date. These monolithic PA chips are fabricated using 0.1-mum AlGaAs/InGaAs/GaAs pseudom orphic T-gate power high electron-mobility transistors on a 2-mil GaAs subs trate, The module assembly and testing, together with the system applicatio ns, will also be addressed in this paper.