Design of a Low Phase Noise and Fine-Tunable VCO for Wideband Application

A voltage-controlled oscillator based on the negative resistance principle with oscillation frequency coverage of 3098 MHz to 3642 MHz at 0–10 V adjustable voltage in low phase noise (PN) is presented in this paper. This circuit consists of three parts, including a resonant circuit for the frequency controller, a transistor part for the instability of the circuit, and a load part for output power. The results using ADS momentum simulation show that the VCO stabilised at 0-5.9 dBm, the PN of less than -83.7 dBc/Hz at 10KHz in the centre frequency of 3.417 GHz, meanwhile, the second harmonic suppression is greater than 35 dBc.