A 1.8~3.1 GHz High-Gain LNA with 1.5~1.7 dB NF in 0.18-μm SiGe BiCMOS Technology

Abstract

This paper presents a 1.8 ~ 3.1 GHz high-gain three-stage low-noise amplifier (LNA) in 0.18- $\mu m$ SiGe BiCMOS technology. Firstly, a 4th-order $\pi$-type input matching network is adopted to achieve both wideband noise and power matching. Secondly, current-reused topology is used in the first two stages for high gain and low power consumption, and the resonance points of each stage are staggered to expand the frequency bandwidth. Thirdly, to improve linearity performance, an optimized multiple gated transistor method (MGTR) is employed in the third stage, which focuses on alleviating the degradation of the transconductance. The post-layout simulated results show that the proposed LNA achieves $26.8 \sim 29.8$ dB power gain and 1.5 $\sim$ 1.7 dB noise Figure (NF) within the 3-dB bandwidth. It also has 1.1 ~ 5.8 GHz S11 bandwidth and $16.2 dBm OIP_{3}$ (third-order output intercept point).