A 26.5-29.5 GHz frequency synthesizer (FS) using 90-nm CMOS technology is presented in this paper. To achieve the low-power consumption and low phase-noise performance, a transformer-feedback voltage control oscillator (TF-VCO) and a low suuply voltage injection-locked frequency divider (ILFD) and current mode logic divider (CML) are implemented. The frequency synthesizing is accomplished by the programmable multi-modulars frequency divider (MMD). The phase noise of proposed frequency sythesizer is -77 dBc/Hz at 1 MHz offset. The power consumption is 24.2 mW.