Low Power Broadband sub-GHz CMOS LNA with 1 GHz Bandwidth for IoT Applications

This paper presents a broadband low-power CMOS low noise amplifier (LNA) in 130 nm technology for sub-GHz Internet of Things (IoT) applications. The proposed circuit consists of a current reuse common source amplifier (CSA) in the forward path, and a positive simple transconductance amplifier (PSTA) in the feedback path. Theoretical calculation of the input admittance shows a positive part that presents a parallel inductance. This equivalent parallel inductance in the input can cancel out the input capacitance of CSA and electrostatic discharge (ESD) pad, enhancing the frequency bandwidth in the sub-GHz frequency band. Post-layout was simulated including ESD pads and package model in 130 nm CMOS technology, LNA achieves a voltage gain of 16.5 dB in a frequency bandwidth of 50 MHz to 1.1 GHz, noise figure (NF) of less than 2.4 dB, input return loss (S11) of -11 dB, input third order intercept point (IIP3) of -11 dBm and 1 mW power consumption from a 1 V power supply, showing a good figure of merit compared to other works. The occupied core area is less than 0.002 mm2.