A DC to 22GHz, 2W high power distributed amplifier using stacked FET topology with gate periphery tapering

This paper describes a high power (2W) distributed amplifier (DA) MMIC. DA MMIC was fabricated using an Lg=0.25μm GaAs PHEMT process. DA MMIC contains an impedance transformer and heavily tapered gate periphery design for constant output power performance over 0.1 to 22GHz operational frequency. To obtain high voltage operation, the DA MMIC employed a three stacked FET topology. A 7-section DA demonstrated 2 W saturated output power and 12 dB small signal gain from 0.1 GHz to 22 GHz with peak output power of 3.5 W with power added efficiency (PAE) of 27%. Those test results exceeded recently reported GaN based power DA performance [4] with large margins.