Toyo Communication Equipment Co., Ltd.

Tomio Satoh

Tsuyoshi Ohshima

Jun Matsuoka

Tetsuya Abe

In a piezoelectric oscillator a non-inverted output terminal () of an ECL circuit () is grounded via a capacitor (C) and is connected to a non-inverting input terminal () of the ECL circuit () via a series connection of capacitors (C) and (C). The non-inverting input () is connected via a resistor Rto an inverting input terminal () of the ECL circuit () and is grounded via a capacitor (C). The connection point of the series connection of the capacitors (C) and (C) is grounded via a crystal oscillator (X'tal) and a frequency control capacitor (C). The output from the ECL circuit () is provided at its inverted output terminal

Emitter coupled logic oscillator circuit

A piezoelectric oscillator including a piezoelectric vibrator that vibrate at desired frequency; a first transistor for exciting the piezoelectric vibrator; a second transistor whose collector connects to an emitter of the first transistor, the second transistor being a base grounded type; a first capacitor connected between the emitter of the first transistor and ground; a series circuit comprising the piezoelectric vibrator and a second capacitor being connected between a base of the first transistor and an emitter of the second transistor, in which the first capacitor and a composition capacitance between base and emitter of the first transistor functions as a split capacitor for a feedback circuit of the Colpitts oscillator.

Piezoelectric oscillator

Design means is provided to prevent electronic parts used in a high-stability piezoelectric oscillator from deterioration due to aging by heat when the high-temperature side of the working temperature range is as high as 85&#xb0; C. A high-stability piezoelectric oscillator, which is provided with a first constant temperature oven having housed therein a piezoelectric resonator and electronic parts for oscillation, a second constant temperature oven having housed herein said first constant temperature oven, and temperature control means for controlling the temperature of each constant temperature oven, and in which the temperature of said first constant temperature oven is set lower than the temperature of said second constant temperature oven, is characterized in that a heat source is disposed near said piezoelectric resonator.

High-stability piezoelectric oscillator

In an inverter oscillation circuit an output terminalof an inverterwith its input and output interconnected via a high resistance Ris grounded via a series connection of a capacitor Cand parallel tuning circuit composed of a capacitor Cand an inductor Lconnected in parallel, and the connection point of this series connection is grounded via a parallel circuit of diodes Dand Dconnected in opposite polarities. The connection point of the series connection is connected to an input terminalof the invertervia series-connected capacitors Cand C, and the connection point of this series connection is grounded via a piezoelectric vibrator Xtal and a frequency adjusting capacitor C. The inverter oscillation circuit is configured to provide its output via a series circuit composed of a resistor Rand a capacitor C

Inverter oscillator circuit

A thin and highly stable piezoelectric oscillator is provided with a piezoelectric vibrator, a mother printed board which supports a piezoelectric vibrator main body on its one face and connects lead terminals to a wiring pattern, oscillating circuit parts which are mounted on one face of the mother printed board to be disposed in close contact with one face of the piezoelectric vibrator main body, adjusting circuit parts which are mounted on the other face of the mother printed board, an internal printed board which is provided in contact with the other face of the piezoelectric vibrator main body, and heater resistors which are mounted on the internal printed board to be disposed in close contact with the other face of the piezoelectric vibrator main body. Thus, since such a configuration is employed that, while the oscillating circuit parts mounted on the mother printed board are brought in close contact with the one face of a metal case of the piezoelectric vibrator, the heater resistors mounted on the flexible printed board are brought in close contact with the other face of the metal case for the piezoelectric vibrator, not only the heater resistors heat the piezoelectric vibrator but also it indirectly heats the oscillating circuit parts efficiently.

Thin and highly stable piezoelectric oscillator, and thin and surface-mounting type highly stable piezoelectric oscillator

A piezoelectric oscillation circuit has a series circuit composed of a capacitor Cbe as a part of a load capacitance and a capacitor Ce inserted and connected between a base of an oscillation transistor TRand the ground, and has an emitter resistor Re connected to a connection midpoint A of the series circuit and an emitter of the oscillation transistor TR. Further, a base bias circuit composed of a resistor RBand a resistor RBis connected to a base of the oscillation transistor TR, has a piezoelectric element Xtal and a capacitor Cinserted and connected in series between the base of the oscillation transistor TRand the ground, and further has a resistor Rc connected to a collector of the oscillation transistor TRtogether with the power supply voltage Vcc line, and has a capacitor Cce connected between the collector and the emitter.

Piezoelectric oscillator having a non-inductive load with a collector-emitter capacitor

The invention provides a temperature compensated crystal oscillator that can obtain a large variable range and that can obtain high temperature stability. This temperature compensation system employs a configuration comprising a oscillation circuitincluding a crystal vibratorhaving a piezoelectric element excited in a given frequency and an oscillation amplifier that excites the piezoelectric element by flowing a current to the piezoelectric element, a vibrator current control circuitthat controls the current of the crystal vibrator, a temperature compensation voltage generation circuitthat compensates for temperature characteristics of the crystal vibrator, and an external variable capacitance diodethat changes the oscillation frequency of the oscillation circuitusing an external variable voltage controller. The vibrator current control circuitcomprises a variable capacitance diodethat controls the vibrator current, and capacitorsto

Crystal oscillator with temperature compensated through a vibrator current control circuit

The present invention has for its object to provide a piezoelectric oscillator that has improved secular variation characteristics and excels in suppressing undesired resonance. The piezoelectric oscillator has a piezoelectric vibrator and an oscillation transistor, and since a collector load resistance, a capacitance, a parallel circuit of a resistance and a capacitance, and said piezoelectric vibrator are connected between the collector of the transistor and an AC-wise grounded power supply, between the emitter and collector of the transistor, between the emitter of the transistor and the ground, and between the base of the transistor and the ground, respectively, it is possible to sharply reduce a current flow through the crystal vibrator, permitting suppression of frequency variations by the secular change characteristics of the oscillator; furthermore, the reduction of the current flow through the piezoelectric vibrator improves C/N and prevents undesired vibration and oscillation as well as decreases secular changes.

In the high-frequency piezoelectric oscillator, capacitors C, Cas a part of a load capacitor are connected between a base of a transistor TRand the ground. The connection point of the capacitors C, Cis connected to an emitter of the transistor TR, and is grounded via an emitter resistor R. A base bias circuit consisting of resistors RBand RBis connected to the base of the transistor TR. A piezoelectric vibrator, an inductor, and a resistor are connected in parallel, and connected between the base of the transistor TR. A capacitor is connected to the parallel circuit and grounded. A collector of the transistor and a power supply line are connected together.

High-frequency piezoelectric oscillator

[Object of the invention] To provide designing means that prevents deterioration through thermal aging of an electronic part used in high-stability piezoelectric oscillators and the like when the high end of the usage temperature is 85 deg C. [Means for solving the problem] In a high-stability piezoelectric oscillator equipped with: a first isothermic oven housing a piezoelectric vibrator and an electronic part; a second isothermic oven; a case; and the like, a high-stability piezoelectric oscillator wherein a temperature of the first isothermic oven is set to be lower than a temperature of a second isothermic oven using a Peltier element or the like.

The piezoelectric oscillator is a Colpitts circuit including a piezoelectric vibrator and a load capacitance in the oscillating loop and a limiter circuit. The excitation signal from the piezoelectic vibrator is supplied to the limiter circuit, and the limiter circuit controls the inter-terminal impedance of the capacitor which is connected to the limiter based on variations in the excitation signal and thus clips the level of the excitation signal.

To obtain means for suppressing a jump phenomenon to a B mode in a Colpitts oscillator using an SC-cut crystal unit. In a Colpitts oscillator including a piezoelectric resonator and an amplifier circuit, a series resonance circuit and a parallel resonance circuit consisting of an inductance and a capacitance are inserted into an oscillation loop, and the frequency of the series resonance circuit is set in the vicinity of the oscillation frequency of the oscillator, and the frequency of the parallel resonance circuit is set in the vicinity of an unwanted oscillation frequency of the oscillator, thereby to suppress the unwanted oscillation.

A piezoelectric oscillator which is excellent in noise characteristic and aging characteristic is implemented by a piezoelectric oscillator comprising: a Colpitts oscillator including a piezoelectric resonator and an oscillation transistor; amplification means for amplifying an output of the Colpitts oscillator; and rectification means for rectifying an output of the amplification means, an output of the rectification means being fed back to base of the oscillation transistor to keep an oscillation output level constant, in which a base bias is set so as to provide the oscillation transistor with an operation point located in the vicinity of a saturation region, and in which a feedback current from the rectification means is supplied to the base of the oscillation resistor so as to make the operation point approach to the saturation region when the saturation output level has become high and so as to make the operation point go away from the saturation region when the oscillation output level has become low. As a result, a piezoelectric oscillator, which is excellent in both noise characteristic and aging characteristic, is realized.

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Kouza-gun, Japan

Tomio Satoh