Abstract: Based on the 90nm CMOS process, a low noise wide tuning range LC voltage controlled oscillator with a resonant frequency of 26 GHz is designed. The parasitic capacitance between adjacent MOM capacitors is analyzed and included in the overall capacitor array, which improves the quality factor of the resonant network and reduces the area. The phase noise of the voltage controlled oscillator is analyzed, and it was optimized by using a large-sized tail current transistor and covering a large area bias filter network structure. The test results showed that the oscillation frequency covered 24.2~29.6 GHz, the phase noise reached -97.4 dBc/Hz at 1 MHz offset from a 26 GHz carrier with a power consumption of 9.6 mW, and the FOMT value of -182.5 dBc/Hz.