Murata Manufacturing Co., Ltd.

Tatsuo Bizen

Atsushi Inoue

Shinji Goma

You Funada

Hiroyuki Yamamoto

Masao Uno

Toshio Hata

Takashi Hiroshima

Kouichi Kongo

A resonance inductor of a resonant circuit is formed of a chip inductor and an inductance fine adjustment pattern. A resonance capacitor is formed of a plurality of chip layered capacitors connected in parallel to each other via connection patterns formed on a substrate. The connection patterns are sequentially disconnected to adjust the capacitance of the resonance capacitor. Then, the inductance fine adjustment pattern is partially removed to adjust the inductance of the resonance inductor.

Method of adjusting the variable range of oscillation frequency of a

In a voltage-controlled oscillation circuit, a parallel resonance circuit which is formed by connecting a coil (an inductive element) and a capacitor (a capacitive element) in parallel with each other is provided between a control terminal and a resonance circuit. A control voltage is inputted at the control terminal and is supplied to the resonance circuit through the parallel resonance circuit, so that the resonance frequency of the resonance circuit is responsive to the control voltage; an oscillation stage of the voltage-controlled oscillation circuit oscillates at that resonance frequency. The oscillation output of the oscillation stage is outputted at an output terminal from a buffer stage through an output matching stage.

Volage-controlled oscillation circuit with an impedance element for

A voltage-controlled oscillation circuit includes a power supply terminal for supplying power to an oscillation stage, a buffer stage, and an output matching stage. Connected between the power supply terminal and ground is a high frequency bypass capacitor for bypassing electrical noise superimposed on the power supply to the side of ground, a voltage feedback resistor is connected in series in a power supply line connected to the power supply terminal, the high frequency bypass capacitor and the voltage feedback resistor constitute a low-pass filter, and the capacitance value of the high frequency bypass capacitor and the resistance value of the voltage feedback resistor are determined so that the cut off frequency of the low-pass filter is at most the frequency f0 of noise.

VCO and buffer having noise filter on power supply line

The size precision of a surface mountable electronic part is improved and a production thereof is simplified. The surface mountable electronic part is constructed such that a circuit substrate is housed in a shield case of which an end side is open, and the shield case is a resin case having a shield film. A connection pattern is formed on the inner surface of the case, with one end of the connection pattern being disposed so as to correspond to an external connection land of the circuit substrate, and with the other end of the connection pattern extending to the open end of the case.

Surface mountable electronic part

In a voltage controlled oscillator, a dielectric resonator is mounted on a circuit board and a metal case is mounted on the circuit board to shield the dielectric resonator. The dielectric resonator comprises a C-shaped first electrode which is provided in a dielectric body, second and third electrodes which are arranged on upper and lower sides of the first electrode, a signal connecting pattern which is extended from the first electrode toward a side surface of the dielectric body, and earth connecting patterns which are extended from the first, second and third electrodes toward the side surface of the dielectric body, to provide predetermined impedance between the earth connecting pattern and the signal connecting pattern. The dielectric resonator is arranged with the second and third electrodes in parallel with a major surface of the circuit board, and the second electrode is upwardly exposed. A portion of the second electrode portion at a predetermined position is adapted to be trimmed so as to regulate the resonance frequency of the dielectric resonator, so as to regulate the oscillator frequency of the voltage controlled oscillator. The dielectric resonator can be miniaturized with no reduction of its Q-value.

Voltage controlled oscillator including a dielectric resonator provided

A selected inductance can be provided by a three-layer structural spiral inductor having an inductor conductive part disposed between two ground electrodes within an electric insulating substrate. This is carried out by eliminating a particular portion of one of those ground electrodes formed on the outer surface of the substrate until a desired inductance is obtained, beginning at a portion of such electrode corresponding to an exposed part of a through hole joint which is electrically connected to an inner peripheral end of a spiral inductor conductive part.

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Kyoto, Japan

Tatsuo Bizen