1-Watt Ka-Band coplanar high power MMIC amplifiers using 0.15 µm GaAs PHEMTs

Two compact coplanar MMIC amplifiers having high output power at Ka-band are presented. Based on our 0.15-æm GaAs PHEMT process on 4 wafers, a two-stage MMIC driver amplifier has demonstrated at 35 GHz, a linear gain of 11 dB, an output power at 1 dB gain compression P(-1dB) of 350 mW, and a saturated output power P(-1dB) greater than 500 mW. At the same frequency, the coplanar high power amplifier achieved a linear gain of 9.5 dB, with P(- 1dB)=725 mW and more than 1 Watt of saturated output power. To our knowledge, this is the highest output power ever reported at Ka-band for any coplanar MMICs.