A linear ultra wide band low noise amplifier using pre-distortion technique

Abstract

This paper presents an Ultra Wide-Band (UWB) high linear low noise amplifier. The linearity of Common Gate (CG) structure is improved based on pre-distortion technique. An auxiliary transistor is used at the input to sink the nonlinear terms of source current, resulting linearity improvement. Furthermore, an inductor is used in the gate of the main amplifying transistor, which efficiently improves gain, input matching and noise performance at higher frequencies. Detailed mathematical analysis show the effectiveness of both linearity improvement and bandwidth extension techniques. Post-layout simulation results of the proposed LNA in TSMC 0.18µm RF-CMOS process show a gain of 13.7dB with −3dB bandwidth of 0.8–10.4GHz and minimum noise figure (NF) of 3dB. Input Third Intercept Point (IIP3) of 10.3–13dBm is achieved which shows 8dB improvement compared to conventional common gate structure. The core circuit occupies an area of 0.19mm2 including bond pads, while consuming 4mA from a 1.8-V supply.