Abstract: In order to improve the performance of wireless communication systems and meet the growing demand for high transmission rates and large capacity, a low-power consumption voltage-controlled oscillator with low phase noise and high tuning gain based on the principle of negative resistance was designed and implemented. The VCO mainly consists of three parts: tuning network, transistor network and load network, including core devices such as silicon-based low-noise transistors and varactor. According to actual measurement, under the condition of supplying a 3 V power supply voltage and an adjustable voltage of 0 V~2.5 V, the frequency tuning range of the VCO is 3 348 MHz~3 523 MHz, the tuning gain is 70 MHz/V, the power consumption is 54 mW and the second harmonic suppression is approximately -35 dBc. When the output frequency is 3 416 MHz, the phase noise at the 10 kHz frequency offset is -83.85 dBc/Hz.