This letter reports a 24 GHz linear up-conversion mixer for high-power IF signal. In the proposed mixer, the double-balanced Gilbert-cell topology is employed with a low-distortion transconductance stage which combines voltage feedback and adaptive biasing schemes. The proposed adaptive biasing circuit improves the linearity of the transconductance stage by providing an additional bias current when IF input signals exceed the current-limited linear input range. Implemented in a 0.13 mu m CMOS technology, the mixer showed a conversion gain of -1.9 dB and output 1 dB compression point of 0.3 dBm for the IF, LO, and RF frequency ranges of 10.0-314.7 MHz, 18.9-29.0 GHz, and 23.4-29.2 GHz, respectively, while dissipating 22.8 and 16.5 mW for the mixer and the LO buffer, respectively, from a 1.5 V supply.