A wideband inductorless LNA utilizing common-source noise-canceling and cascode configuration

Abstract

The common-source noise-canceling (CSNC) and the gyrator are known for alleviating the trade-off between NF and S11 in wideband LNAs. Moreover, the departure of the input-matching stage and signal-amplifying stage in CSNC facilitates the design of the gyrator. Cascode configuration is exploited to boost the feedback gain, enhancing the gyrator-C effect and broadening the input-matching bandwidth. Therefore, large transistors can be used for noise reduction while maintaining a wide operating bandwidth. Post-layout simulation results in 40 nm CMOS technology show that the circuit achieves an NF of 1.37 dB–1.72 dB while maintaining a wide operation bandwidth of 100 MHz to 3.27 GHz. By contrast, the minimum NF achieved by previously published inductorless wideband LNAs is around 2 dB. Moreover, an S21 of 18.9 dB is obtained, making the design suitable for low NF receivers. Besides, the IIP3 (input third-order intercept point) of −7.1 dBm is obtained, and the circuit consumes 13.1 mW at a 1.2 V voltage supply. Being self-biased, the circuit core consumes only 0.0034 mm2 area.