Design of a 2–18 GHz ultra-wideband MMIC low noise amplifier

Abstract

An ultra-wideband low noise amplifier (LNA) is designed based on a uniform distributed topology using 0.25 µm GaAs pseudomorphic high electron mobility transistor (pHEMT) process. In order to increase the amplifier’s high frequency gain and gain flatness and consequently widen its bandwidth, the design proposed a new multi-inductor matching technique based on cascode structure. According to the actual measurement, the circuit adopts a +5 V power supply, and the current is about 86 mA. The bandwidth coverage is 2–18 GHz, the noise figure is less than 3.5 dB, the power gain is greater than 18 dB, and the gain flatness is ±1 dB, which has excellent input and output standing waves, and the saturated output power is greater than 17dBm, and the chip area is 3.1 mm*1.3 mm.