A 50-dB image-rejection SiGe-HBT based low noise amplifier in 24-GHz band

An image-rejection low-noise amplifier (LNA) based on 0.18-mum SiGe BiCMOS technology was developed in order to create a 24 GHz-band RF receiver front-end. Its high image-rejection ratio (IRR) in the quasi-millimeter-wave frequency region is due to the use of a notch feedback circuit. The LNA has a 14-dB gain at an operating frequency of 27.2 GHz and an IRR greater than 50 dB IRR at an image frequency of 21.6 GHz. While its IIP3 is -14 dBm, its power consumption with a 1.2-V power supply is also low, 7.9 mW.