In this paper, we present a wide frequency tuning fundamental voltage-controlled oscillator (VCO). The frequency is tuned by the method of magnetic-tuning, which avoids extra power consumption and obtains a larger frequency tuning range. The output adopts the method of differential to single-ended, and also uses the source degeneration to improves the output power. The design is implemented in 40-nm CMOS 1p6m process, occupying a core area of 0.081 µm². Based on the post-layout simulation results, the proposed VCO exhibits a wide frequency tuning range from 293-to-303-GHz with -4 dBm peak output power, and -99 dBc/Hz phase noise (at 10-MHz offset) while consuming 10.2 mW form 1-V supply (3.9% DC-to-RF efficiency).