A D-band gain-boosted current-bleeding down-conversion mixer is presented in this letter using 65 nm CMOS technology. The proposed down-conversion mixer uses a gain-boosted current-bleeding technique to improve the conversion gain for low power chip to chip communication with a low local oscillator (LO) power. Broadband Marchand baluns were used to transform a single-ended signal to a differential signal at the RF and LO port for measurement. According to experimental results, the proposed mixer had a measured conversion gain of -12 +/- 1 dB at a frequency range from 113 to 127 GHz with an ultra-low LO power of -9 dBm using a gain-boosted current bleeding technique. The LO-to-RF isolation was better than -30 dB. This core chip occupies 350 x 320 mu m(2). The power consumption is 6 mW from a 1 V supply voltage.