A 6.5-kV HBM ESD-protected high-gain LNA using cascaded L-match input network

A wideband (2-3 GHz) three-stage low noise amplifier (LNA) with electrostatic discharge (ESD) protection circuits using 0.18 mu m CMOS technology is presented in this paper. Low-parasitic silicon-controlled rectifier (SCR) devices are co-designed with the LNA in the form of S-parameters, and a new cascaded L-match input network is proposed to reduce the parasitic effects of them on the input matching. To improve linearity performance, an optimized multiple-gated transistors method (MGTR) is proposed and applied to the third stage, which takes both transconductance gm and third-order nonlinear coefficient g(m)" into consideration. The measured results show a wide input matching across 2-8 GHz and a high third-order input intercept point (IIP3) of -12.8 dBm. The peak power gain can achieve 29.1 dB, and the noise figure (NF) is in a range of 3.1-3.6 dB within the 3-dB bandwidth. Using SCR devices with low parasitic capacitance of similar to 80 fF and robust gate-driven power clamps, a 6.5-kV human body mode (HBM) ESD performance is obtained.