A wide-band noise-cancelling direct-conversion balun-LNA-mixer front-end

A wide-band noise-cancelling balun-LNA-mixer front-end for direct conversion receivers is presented in this paper. The proposed circuit exploits an on-chip noise cancelling balun-LNA to achieve low noise figure. This paper presents a novel technique to reduce the noise of the auxiliary amplifier which, in the conventional noise cancelling circuits, is designed to cancel out the noise of the main amplifier. The proposed front-end is designed and simulated in TSMC 0.18 µm RF technology. Simulation results with Spectre, show the high conversion gain of 25.7–28.9 dB and low noise figure of 3.3–3.9 dB all-over the frequency band of 2–4.5 GHz. Also, the S11 of the proposed front-end stays below − 9.3 dB entire the band of interest. IIP2 and IIP3 of the proposed front-end are achieved 67.8 dBm and − 17.4 dBm, respectively. The proposed circuit consumes 17.8 mW power from 1.8 V voltage supply.