Analysis and Design of a 0.6- to 10.5-GHz LNTA for Wideband Receivers

Description

This item from - IEEE Transaction - Components, Circuits, Devices and Systems - A low-noise transconductance amplifier (LNTA) for wideband receivers based on a gm -boosted current mirroring topology that operates over 0.6- to 10.5-GHz is presented. gm boosting relaxes the Gm and S11 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 S11 BW. Despite the high Gm obtained over large BW, high linearity is maintained through the predistortion inherent 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 Gm of 242 mS (170 and 72 mS in paths 1 and 2, respectively). S11 BW and Gm 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.