An 8.3–43-GHz CMOS low-noise amplifier (LNA) with wideband input matching is presented. A gate–drain transformer feedback combined with a series–shunt resonance network is employed in a complementary common-source (CCS) input stage to achieve a broadband, impedance-stable input, and noise matching. A transformer-loaded cascode output stage is implemented to enhance gain, while a pole-tuning technique is adopted to achieve a broadband gain response. Fabricated in 65-nm CMOS, the LNA achieves a peak gain of 14.7 dB and a 3-dB bandwidth from 8.3 to 43 GHz with a fractional bandwidth of 135.3%. Good input matching is maintained across 8–55 GHz. The input 1-dB compression point (IP 1dB ) ranges from –14.3 to –9.3 dBm. A minimum noise figure (NF) of 3.47 dB is measured, and the power consumption is 25.9 mW under a 1.2-V supply.