An 8-Watt 250-3000 MHz Low Noise GaN MMIC Feedback Amplifier with > +50 dBm OIP3

Abstract

This paper describes a compact GaN MMIC cascode feedback amplifier design which achieves up to 8-Watts of power and IP3 greater than +51 dBm across a decade of BW. The design is made of 0.25um GaN HEMT technology with fT~50 GHz and BVgd > 60V. A 40V-750mA high-bias design achieves an OIP3 of 51.9 dBm, P1dB of 38.5 dBm, and NF ~ 3dB at 2 GHz. A 40V-500mA medium-bias design achieves a lower NF ~ 2.5 dB, an OIP3 of 48.4 dBm and a P1dB of 36.8 dBm. This combination of high linear IP3 and low NF exceeds that achieved by many state-of-the-art PHEMT, HBT and HFET technologies for decade-BW MMIC amplifiers operating in the S- and C-band frequency regime. The cascode approach is used to distribute voltage and self-heating in order to lower the Tj and NF while providing high linearity by operating from a higher supply voltage. These results suggest promise for next generation CATV, FTTX, software defined radio and BTS applications which demand higher linearity and BW to satisfy the high data throughput systems of the future.