A 0.5 watt-40% PAE InP double heterojunction bipolar transistor K-band MMIC power amplifier

We report on the first InP DHBT K-band fully integrated power amplifier which achieves 0.5 Watts of output power and 40% power added efficiency (PAE). The power DHBTs obtain a BVceo >18 V and an f/sub T/ and f/sub max/ of 80 GHz and 160 GHz, respectively. The MMIC amplifier combines eight 1.5/spl times/30 /spl mu/m/sup 2/ emitter fingers for a total periphery of 360 /spl mu/m/sup 2/. At 21 GHz the MMIC power amplifier achieves a linear gain of 9.4 dB, output power of 27 dBm with a 40% PAE. The amplifier was operated under a Vce=5.5V and Jc=54 KA/cm/sup 2/ and obtained a corresponding power density of 1.4 mW//spl mu/m/sup 2/. To our knowledge this is the highest output power obtained for a fully monolithic-50-/spl Omega/-matched MMIC power amplifier based on InP HBT technology.