A novel low power UWB cascode SiGe BiCMOS LNA with current reuse and zero-pole cancellation

Abstract

A low power cascode SiGe BiCMOS low noise amplifier (LNA) with current reuse and zero-pole cancellation is presented for ultra-wideband (UWB) application. The LNA is composed of cascode input stage and common emitter (CE) output stage with dual loop feedbacks. The novel cascode-CE current reuse topology replaces the traditional two stages topology so as to obtain low power consumption. The emitter degenerative inductor in input stage is adopted to achieve good input impedance matching and noise performance. The two poles are introduced by the emitter inductor, which will degrade the gain performance, are cancelled by the dual loop feedbacks of the resistance-inductor (RL) shunt–shunt feedback and resistance-capacitor (RC) series–series feedback in the output stage. Meanwhile, output impedance matching is also achieved. Based on TSMC 0.35μm SiGe BiCMOS process, the topology and chip layout of the proposed LNA are designed and post-simulated. The LNA achieves the noise figure of 2.3–4.1dB, gain of 18.9–20.2dB, gain flatness of ±0.65dB, input third order intercept point (IIP3) of −7dBm at 6GHz, exhibits less than 16ps of group delay variation, good input and output impedances matching, and unconditionally stable over the whole band. The power consumption is only 18mW.