Journals Proceedings

Abstract

Non - Foster circuits are widely used to enhance the bandwidth of microwave circuits owing to its ability to provide the negative impe dance required to cancel transistor parasitic capacitance. In this paper, a 53 to 56 GHz MMIC (monolithic microwave integrated circuit) non - Foster enhanced class - J GaAs pHEMT (gallium arsenide pseudo high electron mobility transistor) power amplifier (PA) is proposed. The non - Foster circuit (NFC) is used to enhance the PA output power and gain. The NFC and PA were designed with WIN semiconductor’s P10 - 10 process GaAs pHEMT with periphery of 150 μm. The transistor was biased with drain supply voltage of 2V f or the NFC and 3V for the PA with respective quiescent drain - to - source current (I DSQ ) of 2mA and 3mA respectively. The PA operates from 53GHz to 56GHz with center frequency of 54.5GHz. The NFC effective negative capacitance stood at - 0.15pF at 54.5GHz. Sma ll and large signal simulations result of the PA with and without NFC were obtained and compared at the center frequency The NFC MMIC PA measures 0.9 x 1.0 mm 2 (0.9 mm 2 ). Simulation results indicate that the PA with NFC demonstrates higher output power of 17dBm, gain of 8dB and 43% PAE than the one without NFC with 15.5dBm output power, 41.5% PAE and 6.5 dB power gain .