Compact and low power consumption K-band differential low-noise amplifier design using transformer feedback technique

A compact and low power consumption three-stage differential K-band low-noise amplifier (LNA) with a 10 dB differential mode gain at 25.8 GHz and a 3 dB bandwidth of 22.8-26.8 GHz by using a transformer feedback technique with standard 0.18 mum CMOS technology is presented. The minimum input and output return losses over a 3 dB bandwidth are 11 and 7 dB, respectively. Fully differential characterisations of the noise figure (NF) and the common mode rejection ratio (CMRR) are demonstrated. The obtained NF and CMRR are 4.84 dB and 23.3 dB at 25.8 GHz. The input 1 dB compression point and input third-order intercept point are 17.8 and 5 dBm, respectively. The overall power consumption is 25.6 mW. This three-stage differential LNA only occupies an area of 0.63 x 0.88 mm².