A FET transistor voltage-controlled oscillator is provided that includes a crossed-coupled inductor capacitor tank (LC-Tank) transistor voltage-controlled circuit having a first transistor and a second transistor, as well as a transistor frequency multiplying circuit having a third transistor and a fourth transistor. In the design, the gate of the first transistor is connected to the drain of the second transistor, and the gate of the second transistor is connected to the drain of the first transistor. Then, the source of the third transistor is connected to the source of the first transistor, and the source of the fourth transistor is connected to the source of the second transistor. Last, the gate of the third transistor is connected to the gate of the fourth transistor, and the drain of the third transistor is connected to the drain of the fourth transistor. Therefore, the parasitic capacitance present in the first transistor and the parasitic capacitance present in the second transistor generate an effect similar to two capacitors connected in series, via the transistor frequency multiplying circuit. The effect reduces the total capacitance of the voltage-controlled oscillator, to increase the working frequency of the voltage-controlled circuit and allow a circuit having the voltage-controlled circuit to operate at a high frequency.