A Dual-feedback K-band Low-noise Amplifier with Transformer Neutralization Technique

A dual-feedback K-band low-noise amplifier (LNA) is presented. This circuit consists of two common-source configurations in series. Its input matching network uses the shunt inductive transformer technique to reduce the chip area and improve noise matching, and uses the transformer technique to improve the gain and isolation. The measured input and output return losses are less than -10 dB at 23 GHz, the isolation is -50 dB, and the gain at 23 GHz is 10.6 dB. This chip is implemented by 0.18 m CMOS technology and its dimensions are 0.22 mm 2 . The DC power consumption is 5.4 mW with a supply voltage of 1 V. This amplifier can improve a complete RF front-end for sensor applications.