Murata Manufacturing Co., Ltd.

Osamu Oe

Tomohide Aramata

Teruhisa Tsuru

Toshio Hata

Satoru Muto

A voltage controlled oscillator includes a resonant circuit having a choke coil, a variable-capacitance diode, coupling capacitors, a resonant capacitor, a resonator, and a bypass capacitor. An amplifying circuit includes a buffer amplifying transistor, an oscillating transistor, bias resistors, Colpitts capacitors, bypass capacitors, a coupling capacitor, a choke coil, a resonant capacitor, and a resonant inductor which is an inductor element. A bias resistor has one end electrically connected to the base of the oscillating transistor and has the other end electrically connected to the ground via the resonant inductor having one end electrically grounded.

Voltage-controlled oscillator, composite module, and communication apparatus

A resonant circuit includes a choke coil, a variable-capacitance diode, coupling capacitors, a resonant capacitor, a resonator defining an inductor element, and a bypass capacitor. An amplifying circuit includes a buffer amplifying transistor, an oscillating transistor, bias resistors, Colpitts capacitors, bypass capacitors, a coupling capacitor, a choke coil, a resonant capacitor, and a resonant inductor. A bias resistor has one end electrically connected to the base of the oscillating transistor and has the other end electrically connected to the ground via the resonator having one end electrically grounded.

Voltage controlled oscillator, composite module, and communication apparatus

A voltage controlled oscillator is provided which oscillates in a stable manner at a high frequency and obtains a large variable range of frequency. The oscillator includes a transistor, and distributed-constant line connected to the base of the transistor. The distributed-constant line has substantially 1/4 wavelength at the oscillation frequency of the oscillator, and has one open end. An inductance element is provided comprising a capacitor having a self-resonance frequency which is lower than the oscillation frequency. This inductance element is connected to the collector of the transistor. A varactor diode is connected to the capacitor.

Voltage controlled oscillator and electronic apparatus using same

A small-sized oscillator which readily oscillates and an oscillation apparatus using same are described. In the oscillator, an oscillation transistor, such as a silicon bipolar transistor, is arranged on a dielectric substrate and a quarter-wave open-circuit terminal stub is connected to the base of the oscillation transistor. Also, the collector of the oscillation transistor is grounded through a capacitor. In addition, the emitter of the oscillation transistor is connected to the collector and base through feedback capacitors C,and C,respectively. In this case, the quarter-wave open-circuit terminal stub can be considered grounded from the standpoint of distributed constants, and accordingly, the oscillator is also grounded.

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Komatsu, Japan

Osamu Oe