A low-power 3.2-9.7 GHz ultra-wideband low-noise amplifier with excellent stop-band rejection using 0.18-μm CMOS technology

A low-power 3.29.7 GHz low-noise amplifier (LNA) with excellent stop-band rejection by 0.18-mu m CMOS technology is demonstrated.High stop-band rejection is achieved using a planar passive band-pass filter with three finite transmission zeros (in the input terminal of the common-gate LNA), one of which (omega z1 = 0.9 GHz) is in the low-frequency stop-band and the other two (omega z3 and omega z5) are in the high-frequency stop-band. In addition, an active notch filter is used in the output terminal of the LNA to introduce another low-frequency stop-band transmission zero (omega z2) at 2.4 GHz. The LNA consumes 4.68 mW and achieves S11 of -10 to -39.5 dB, S21 of 9.3 +/- 1.5 dB, and an average noise figure (NF) of 6 dB over the 3.29.7 GHz band. Moreover, the stop-band interferers can be effectively attenuated. The measured stop-band rejection is better than 21.6 dB for frequencies DC similar to 2.5 GHz and 11.220 GHz. The corresponding stop-band rejection at 0.9, 1.8, 2.4, 17.6, and 19.5 GHz are 53.3, 26.4, 26.5, 60, and 59.5 dB, respectively. (C) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:12531261, 2012