3.2-9.7 GHz ultra-wideband low-noise amplifier with excellent stop-band rejection

A low-power 3.2-9.7-GHz ultra-wideband low-noise amplifier (UWB LNA) with excellent stop-band rejection by 0.18--m CMOS technology is demonstrated. High stop-band rejection is achieved by using a passive bandpass filter (BP-filter) with three finite transmission zeros (in the input terminal), one of which (ω_z1=0.9=GHz) is in the low-frequency stop-band and the other two (ω_z3 and ω_z5) are in the high-frequency stop-band. In addition, an active notch filter is used in the output terminal to introduce another low-frequency stop-band transmission zero (ω_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 NF of 6±dB over the 3.2±9.7±GHz band. The measured stop-band rejection is better than 21.6±dB for frequencies DC±2.5 and 11.2±20±GHz.