High Output Power and Efficiency 300-GHz Band InP-Based MOS-HEMT Power Amplifiers With Composite-Channel and Double-Side Doping

This paper demonstrated high-output-power and high-efficiency power amplifier (PA) monolithic microwave-integrated circuit (MMIC) at 300-GHz band (252–296 GHz) with the use of InPbased metal–oxide–semiconductor high-electron-mobility transistors (HEMTs) with composite-channel (CC) and double-side-doping (DD) techniques. The CC-DD structure obtained high output current and low channel resistance due to the improved carrier density and mobility. W-band load-pull measurement revealed the drastically improved output power density of CC-DD structure compared with that of singlechannel DD structure. The 2-stage cascaded, 4-way, and 16-way PA-MMICs were designed based on stacked common-gate transistors with current reuse topology. The cascaded PA-MMIC exhibited a poweradded efficiency (PAE) of 7.8%, and the 16-way PA-MMIC exhibited an output power of 16.9 dBm. These values are the highest among all the values reported for the 300-GHz band PA-MMICs. The 4-way PA-MMIC achieved a high output power of 13.6–14.6 dBm and high PAE of 4.8%–6.3% simultaneously at the entire 300-GHz band.