A 2-decades wideband low-noise amplifier with high gain and ESD protection

Abstract

This work presents a 2-decades wideband (15.5 MHz-1.55 GHz) low-noise amplifier (LNA) circuit. As its wideband range extends from HF to UHF, it includes, among others, the ISM bands (27.12 MHz, 40.7MHz, 434.79 MHz, 928 MHz), the GSM850 and GSM900 bands, and IEEE 802.22 WRAN bands (54 MHz-862 MHz). The proposed circuit operates also as a balun (single-ended input - differencial output) and its layout presents a very small area, an important savings resulting from this inductorless design for the LNA. An auxiliary amplifier was introduced so that a high gain and a high IIP3 can be achieved with low Noise Figure (NF). The linearity was improved using a distortion cancellation strategy and the NF was improved through a noise canceling technique. The amplifier was implemented in a 130 nm CMOS process, using a PDK from Silterra foundry, in a compact 77μm × 54μm core area. Simulations including post-layout parasitics, bondwire, ESD protection and PAD input parasitics resulted (over the entire band) in a voltage gain of 20.8-24.9 dB, a noise figure (NF) of 2.7-3.7 dB, an input power reflection coefficient Sn <; -11.4 dB, an input third-order intercept point (IIP3) = -0.4 dBm (@750MHz), and a power consumption of 10.4 mW under 1.2 V supply. This balun LNA shows a worst case gain imbalance between outputs of 1.2 dB and very low sensitivity to temperature variations for gain, NF and Sn in the range of 0 to 85°C.