A high image rejection SiGe low noise amplifier using passive notch filter

Abstract

A new design is presented that combines a low-noise amplifier (LNA) with a new passive base-collector notch filter based on Jazz 0.18 µm SiGe technology. Extra capacitor is introduced in notch filter, eliminating the operating-frequency input mismatch in formal base-collector notch filters. Results show that LNA obtains a 4 dB S₂₁ enhancement of 14.1 dB and a 7dB increase S₁₁ of -15dB at 20.5 GHz, image rejection ratio is 33.5 dB. IIP3 is 3.43 dBm at the operating frequency for a power consumption of 18 mW from a 3 V power supply.