Compact and broadband microstrip power amplifier MMIC with 400-mW output power using 0.15-/spl mu/m GaAs PHEMTs

The performance of a compact power amplifier MMIC for 35 to 45 GHz applications is reported. Using a standard 6-inch, 0.15-/spl mu/m GaAs power PHEMT technology on 100-/spl mu/m substrate thickness, in combination with appropriate compact circuit topologies, this microstrip power amplifier achieved a linear gain of more than 24 dB over the 36 to 45 GHz frequency range. At 5 V and 500 mA bias, an output power at 1-dB compression of 26 dBm (P/sub -1 dB/=400 mW) was measured in the 37/spl sim/40 GHz band, with a saturated output power up to 0.5 Watt (P/sub sat/=27 dBm). The total chip size is only 3.6 mm/sup 2/ (2.4 /spl times/ 1.5 mm/sup 2/); compared to conventional power amplifier MMICs operating at these frequencies, the combined output power and gain densities per chip area are a factor two higher.