A 30-GHz 1-W power HEMT

Millimeter-wave power high electron mobility transistors (HEMT's) employing a multiple-channel structure have been fabricated and evaluated in the R-band frequency range. An output power of 1.0 W (a saturated output power of 1.2 W) with 3.1-dB gain and 15.6-percent efficiency was achieved at 30 GHz with a 0.5-µm gate-length and 2.4-mm gate-periphery device. At 35 GHz, a 2.4-mm device delivered 0.8 W with 2.0-dB gain and 10.7-percent efficiency. These are the highest output power figures reported to date for single-chip power FET's in the 30-GHz frequency range.