Patent ID: 8283989

Claim:
A voltage controlled oscillator, comprising: a substrate comprising quartz; a resonance part including a variable capacitance element and an inductance element, the variable capacitance element having a capacitance which changes according to control voltage for frequency control inputted from an external part, in which a series resonance frequency is adjusted according to the capacitance; a transistor for amplification having a base connected to the resonance part; and a first feedback capacitance element and a second feedback capacitance element, which are connected between a base of the transistor and ground and connected in series with each other, the emitter of the transistor being connected therebetween; wherein the first feedback capacitance element is connected between a base terminal on the substrate on which a pin that extends from the base of the transmitter is mounted, and an emitter terminal on the substrate, on which a pin that extends from the emitter of the transmitter is mounted, the first feedback capacitance element formed by a comb electrode comprising a first and a second common electrode that are formed parallel to each other so as to intersect a line that joins said first and second common electrodes, a first group of electrode fingers extending from the first common electrode in a comb shape, and a second group of electrode fingers extending from the second common electrode in another comb shape, the comb shape of the first group being interdigitated with the another comb shape of the second group; wherein the distance between the base terminal and the emitter terminal is no greater than 120 μm; and wherein the series resonance frequency is no less than 5 GHz.