Design and Simulation of X Band LNA for Aircraft Receiver

Abstract

This paper proposes a highly linear low noise amplifier (LNA) for ultra-wideband applications. It focuses on linearization of the basic active gm-boosted common gate (CG) LNA circuit by exploring the non-linearity coefficients using the generalized nonlinearity model. Mathematical analysis shows that in active gm-boosted CG LNA, the third input intercept point (IIP3) of LNA depends on interaction between main and auxiliary amplifiers. Post-layout simulation results of the proposed LNA circuit in a 180 nm RF CMOS process show 5.19 dBm of IIP3 that indicates 4 dB improvement comparing with conventional structures. The proposed wideband LNA has a voltage gain of 18 dB, 4dB bandwidth from 8 GHz to 12 GHz, and minimum noise figure (NF) of 3.6 dB. The simulated S11 is better than -14 dB in whole frequency range while the LNA core draws 3 mA from a single 1.8 V DC voltage supply.