A low‐power 3.2–9.7 GHz low‐noise amplifier (LNA) with excellent stop‐band rejection by 0.18‐μm 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 (ωz1 = 0.9 GHz) is in the low‐frequency stop‐band and the other two (ωz3 and ωz5) 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 (ωz2) 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 3.2–9.7 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 ∼2.5 GHz and 11.2–20 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. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1253–1261, 2012