A Wide-Band CMOS Variable-Gain Low Noise Amplifier for Multi-Standard Terrestrial and Cable TV Tuner

A CMOS wide-band low noise amplifier (LNA) based on the current amplification for the multi-standard terrestrial and cable tuner is proposed. Conventional wide-band LNAs suffer from the tradeoff between noise figure and wide-band input matching. By adopting the structure combined the common source (CS) amplifier with the common gate (CG) amplifier by the current amplification, the noise figure does not have any influence on wide-band input matching so that we can achieve low noise figure by the noise canceling and excellent wide-band input matching at the same time while allowing some variable gains. The proposed LNA is fabricated in 0.18-mum CMOS process and achieves a power gain of +15.5~-5.5 dB, an average noise figure of 3.6 dB, an IIP3 of -1 dBm at the maximum gain, and S11 of -15 dB. The power consumption is 50.4 mW and chip area is 0.54 mm².