Low-noise voltage controlled oscillator

A low-noise voltage controlled oscillator provided with an oscillation element that oscillates an oscillatory frequency;

• and a transistor that keeps the oscillatory frequency and has a negative resistance, the low-noise voltage controlled oscillator having a frequency variable range, comprising:
• a first capacity and a second capacity connected in series between a collector and an emitter of the transistor;
• a third capacity connected in series between the collector and the emitter to be in parallel with the first and the second capacities connected in series, an electrical potential between the first and the second capacities being applied to a base of the transistor;
• a one-port circuit provided between the collector and the first capacity;
• and
• a capacity for correction connected in parallel with the first and the second capacities connected in series,
• wherein the one-port circuit includes a tuned circuit including a variable capacitor capable of adjusting a capacity thereof smaller and an inductor capable of adjusting a value of inductance larger so as to increase a value of impedance.