A 10 GHz low-noise voltage-controlled oscillate (VCO) is proposed in this letter by 0.18 mum RF CMOS process for radar receiver. In the letter a pair of high Q inductors and differential collpitt cores adopt in a 0.18 mum CMOS technology to achieve a better phase noise performance and wide tuning range. The VCO operates from 10.0 GHz-11.0 GHz with 10% tuning range and has two independent outputs. The realized VCO works in the PLL system for the radar receiver. The measured phase noise at 1 MHz offset is -110 dBc/Hz from 10.14 GHz. The measured phase noise at 1 KHz offset is -85 dBc/Hz from 10.14 GHz.