A 1.8 dB NF Blocker-Filtering Noise-Canceling Wideband Receiver With Shared TIA in 40 nm CMOS

Abstract

This paper presents a high-performance two-path wideband receiver (RX) for 4G LTE applications. The RX uses an extra GM stage after the LNA to improve the noise figure (NF). Furthermore, different RF and baseband blocker rejection techniques are proposed to significantly improve the linearity of the RX. The blockers are first rejected after the LNA stage through an N-path filter. Then, a novel base-band blocker filtering (BBBF) technique improves IIP3 by 7 dB. A dual-mixer architecture is also employed to attenuate blockers both before and after the mixer stage. The N-path filter noise is sensed out-of-phase by the RX main path and cancelled at the inputs of the shared TIA. The RX achieves 1.8 dB NF with 50 dB gain at 2 GHz in 40 nm CMOS technology. The RX out-of-band IIP3 is +5 dBm, which is improved by 20 dB employing the proposed techniques, while consuming 36 mW.