High linearity-wideband PHEMT Darlington amplifier with +40 dBm IP3

This paper reports on a 0.1-3 GHz broadband matched Darlington feedback amplifier with over 40 dBm of OIP3 operating from a 5V supply. The Darlington performance is enabled by 0.5um E- mode PHEMTs with fT ~ 30 GHz. The PHEMT Darlington achieves 13 dB of gain at 2 GHz and is monolithically matched to 50 ohms across a wide 0.1-3 GHz bandwidth. The IRL and ORL are better than 15 dB across the band. Noise figure of 3.3 dB and OIP3 of 41.4 dBm are achieved at 2 GHz with a PldB compression of 21.8 dBm. The monolithically matched amplifier achieves > 40 dBm IP3 across a wide 3 GHz band. The total current consumption is only 115 mA through a 5V supply and the LC-measured junction temperature is less than 125C @ 85C base-plate. These are believed to be the best IP3 results reported for a 5V wide band Darlington feedback amplifier at 2 GHz and above.