A low-noise transconductance amplifier (LNTA) for wideband receivers based on a g m -boosted current mirroring topology that operates over 0.6-to 10.5-GHz is presented. g m boosting relaxes the G m and S 11 bandwidth (BW) tradeoff and the noise figure (NF) and input matching tradeoff. The active feedback synthesizes a second-order input impedance profile that further extends the S 11 BW. Despite the high G m obtained over large BW, high linearity is maintained through the predistortion inherent

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... in the current mirroring topology. The LNTA is used in a 65-nm CMOS wideband channelizing iterative downconversion receiver targeting spectrum and signal analysis for cognitive radio and performs active signal splitting across two paths with a total postlayout simulated G m of 242 mS (170 and 72 mS in paths 1 and 2, respectively). S 11 BW and G m BW both exceed 10.5 GHz. Minimum LNTA NFs simulated in the two paths are 4 and 4.8 dB, respectively. Simulated wideband IIP3 and blocker P1dB are +6 and +1.5 dBm, respectively. Measurements of a direct conversion receiver in path 2 closely match simulations.