A 5.2GHz LNA in 0.35µm CMOS utilizing inter–stage series resonance and optimizing the substrate resistance

A current-reused two-stage low noise amplifier (LNA) topology is proposed, which adopts a series inter-stage resonance and optimized substrate resistance of individual transistors. The characteristics of the series inter-stage resonance in gain enhancement are analyzed and compared with other alternatives. The contradicting effects of substrate resistance on common-source and common-gate amplifiers are analyzed and suggested guidelines for high gain operation along with supporting measurement results. The proposed LNA is implemented based on a 0.35 µm CMOS technology for 5.2GHz WLAN. Measurements show power gain = 19.3 dB, NF = 2.45 dB, and IP3 = 13.2 dBm, respectively, for the dc power supply of 8mA and 3.3 V.

[1]  Hans Hjelmgren,et al.  Small-signal substrate resistance effect in RF CMOS identified through device simulations , 2001 .

[2]  C. Enz,et al.  MOS transistor modeling for RF IC design , 2000, IEEE Journal of Solid-State Circuits.

[3]  Qiuting Huang,et al.  Broadband, 0.25 /spl mu/m CMOS LNAs with sub-2dB NF for GSM applications , 1998, Proceedings of the IEEE 1998 Custom Integrated Circuits Conference (Cat. No.98CH36143).

[4]  Suet Fong Tin,et al.  Substrate network modeling for CMOS RF circuit simulation , 1999, Proceedings of the IEEE 1999 Custom Integrated Circuits Conference (Cat. No.99CH36327).

[5]  M.N. El-Gamal,et al.  2.4-5.8 GHz CMOS LNA's using integrated inductors , 2000, Proceedings of the 43rd IEEE Midwest Symposium on Circuits and Systems (Cat.No.CH37144).

[6]  H.R. Rategh,et al.  A 5-GHz CMOS wireless LAN receiver front end , 2000, IEEE Journal of Solid-State Circuits.

[7]  M. Steyaert,et al.  High-performance 5.2 GHz LNA with on-chip inductor to provide ESD protection , 2001 .

[8]  E. H. Westerwick.  A 5 GHz band CMOS low noise amplifier with a 2.5 dB noise figure , 2001, 2001 International Symposium on VLSI Technology, Systems, and Applications. Proceedings of Technical Papers (Cat. No.01TH8517).