This paper introduces a voltage-controlled oscillator (VCO) with low phase noise and low power consumption, implemented using a 65-nm CMOS technology. The design features a resonator with dual cross-coupled PMOS transistors and an AC-coupled variable capacitor, reducing VCO gain and significantly improving phase noise. Moreover, the design incorporates six sets of switchable capacitors to broaden the tuning range of the oscillator, resulting in a wide frequency spectrum while preserving low phase noise. Post-simulation results show that at a supply voltage of 1.2 V, the VCO consumes 3.49 mW and has an oscillation frequency range from 4.78 to 5.24 GHz. At an output frequency of 4.90 GHz, the phase noise measures −128.66 dBc/Hz at a 1 MHz offset, and the root mean square jitter is 425.85 fs. This low-noise, low-power, wide-bandwidth VCO is ideal for high-precision clocks, wireless systems, and high-speed data converters requiring quality clock signals.