| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage controlled oscillator which selectively increases attenuation in a higher harmonic signal band without deteriorating signal level and its flat characteristics in the oscillating frequency band. SOLUTION: The voltage controlled oscillator is composed of a oscillating circuit part A which decides oscillating frequency based on a control voltage Vt, a negative resistance circuit part B which is connected to the circuit part A and includes a transistor for oscillation Q2 and a amplifier circuit part C which includes a transistor for the amplifier Q1, of which emitter is connected to the collector of the transistor for the oscillator Q2. A capacitor C9 is connected between the connection point of transistor for the amplifier Q1 and transistor for the oscillator Q2 and ground potential. The voltage controlled oscillator is characterized in having a second capacitor C91 which has capacitance for the above frequency of higher harmonic signal of oscillating frequency becomes self resonant frequency is connected between the above connection point and ground potential in parallel with the above capacitor C9.
|
