A 0.13-µm CMOS 2.4-GHz low-noise balun-mixer is proposed, where a noise-canceling transconductance stage is adopted for low-noise characteristics. A current-bleeding circuit with an LC resonator is also adopted to further improve the noise figure of the proposed balun-mixer, without additional DC power consumption. The measured results show a DSB NF of 5.5 dB over output IF frequency ranges of 10 to 100 MHz, a conversion gain of 19 dB, and an input P1 dB of -16 dBm. The proposed balun-mixer is implemented in 0.13-µm CMOS technology and consumes only 4.5 mA from a 1.5-V supply voltage.