A wideband receiver front-end employing feedback input matching and feed-forward blocker cancelling

Abstract

In this paper, we propose a wideband receiver that can achieve wideband input matching characteristic and remove out-of-band blocker signals. A wideband input matching is achieved by adding a feedback path to a basic wideband receiver structure consisting of low-noise transconductance amplifier (LNTA), passive mixer, and baseband transimpedance amplifier (TIA). We also proposed a method of cancelling the blocker signal by adding an auxiliary downconversion path. This method can minimize the additional circuit by using the transparent characteristics of the passive mixer and can eliminate the blocker signal without causing the performance degradation of the receiver to be large. A wideband receiver circuit designed with 65nm process was simulated. The receiver can cover the frequency range from 50 MHz to 1.95 GHz and has 47.9 dB gain and 4.1 dB noise figure performance. It also achieves an additional 9.8 dB of blocker signal cancellation over the basic wideband receiver.