Abstract: A quartz oscillator for quadrature modulation has a quartz oscillating circuit including a transistor, a quartz oscillator, a capacitor, and a resistor, a double-mode quartz filter, a reactance element, and an amplifier. The quartz oscillator is constituted so that an output of the quartz oscillating circuit is a first output, and its output is connected to one terminal of the double-mode quartz filter where a common electrode is grounded. The reactance element is connected in parallel between the other terminal and the ground, and a second output is obtained from a connected point via the amplifier.

Abstract: In the case where an ultraminiature piezoelectric substrate, which has a resonating portion formed by making a concavity by etching in the surface of the piezoelectric substrate made of an anisotropic crystal material, is mass-produced by batch operation using a large-area piezoelectric substrate wafer, an annular portion surrounding each concavity is formed sufficiently thick to prevent cracking from occurring when the wafer is severed.

Abstract: In a piezoelectric oscillator a non-inverted output terminal (3) of an ECL circuit (10) is grounded via a capacitor (C3) and is connected to a non-inverting input terminal (5) of the ECL circuit (10) via a series connection of capacitors (C4) and (C5). The non-inverting input (5) is connected via a resistor R1 to an inverting input terminal (4) of the ECL circuit (10) and is grounded via a capacitor (C2). The connection point of the series connection of the capacitors (C4) and (C5) is grounded via a crystal oscillator (X'tal) and a frequency control capacitor (C1). The output from the ECL circuit (10) is provided at its inverted output terminal 2.

Abstract: As a ½ wave plate constituted by laminating two wave plates, a wave plate where temperature dependence of a phase difference is reduced is provided. In a wave plate constituted by laminating a first wave plate having a phase difference ?1 (deg.) and an optical axis azimuth ?1 (deg.), and a second wave plate having a phase difference ?2 (deg.) and an optical axis azimuth ?2 (deg.), the phase difference ?1 (deg.) of the first wave plate and the phase difference ?2 (deg.) of the second wave plate are set to 360n+180 (n=0, 1, 2 . . . ), and an angle formed by polarization planes of incident light and emitted light is ? (deg.). In this case, the first wave plate and the second wave plate are laminated so as to satisfy ?1=(90+?/2)/2 and ?2=?1+90+?/2.

Abstract: 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.

Abstract: To provide a high quality SAW device with enhanced productivity, wherein an outer face of a SAW chip mounted on a mounting substrate is covered with a heat-softened resin sheet and resin is filled on the SAW chip to form an airtight space below an IDT in the SAW device.

Abstract: With a surface mount SAW device constituted so that an outer surface of a SAW chip is covered with a heated and softened sheet resin, a resin is filled into skirts of the SAW chip, and so that an airtight space is thereby formed below IDT electrode on a lower surface of the SAW chip, it is possible to dispense with negative pressure suction from through holes formed in a mounting substrate so as to ensure a filling amount of the resin into gaps, and dispense with strict management of heating temperature and suction profiles.

Abstract: 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° 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.

Abstract: In a Colpitts quartz oscillation circuit, large negative resistance values are obtained in a high frequency band, and in the GHz band in particular. In a piezoelectric oscillator having a Colpitts oscillator, a voltage control circuit, and a coupling capacitor that couples the Colpitts oscillator and the voltage control circuit, an output of the voltage control circuit is feed back to a collector of the Colpitts oscillator via the coupling capacitor.

Abstract: In the case where an ultraminiature piezoelectric substrate, which has a resonating portion formed by making a concavity by etching in the surface of the piezoelectric substrate made of an anisotropic crystal material, is mass-produced by batch operation using a large-area piezoelectric substrate wafer, an annular portion surrounding each concavity is formed sufficiently thick to prevent cracking from occurring when the wafer is severed.

Abstract: In an inverter oscillation circuit an output terminal 2 of an inverter 1 with its input and output interconnected via a high resistance R1 is grounded via a series connection of a capacitor C1 and parallel tuning circuit composed of a capacitor C2 and an inductor L1 connected in parallel, and the connection point of this series connection is grounded via a parallel circuit of diodes D1 and D2 connected in opposite polarities. The connection point of the series connection is connected to an input terminal 3 of the inverter 1 via series-connected capacitors C3 and C4, and the connection point of this series connection is grounded via a piezoelectric vibrator Xtal and a frequency adjusting capacitor C7. The inverter oscillation circuit is configured to provide its output via a series circuit composed of a resistor R2 and a capacitor C6.

Abstract: To provide a high quality SAW device with enhanced productivity, wherein an outer face of a SAW chip mounted on a mounting substrate is covered with a heat-softened resin sheet and resin is filled on the SAW chip to form an airtight space below an IDT in the SAW device.

Abstract: 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.

Abstract: The present invention provides a method for making high-frequency piezoelectric resonators so that constants of the resonator can be measured precisely. A cavity is formed at a central section of an AT-cut crystal substrate. Two grooves are formed at predetermined distances from the left and right of the cavity, and two more grooves are formed at predetermined distances outward from these two grooves. Two more grooves perpendicular to the first set of grooves are formed. A pair of main electrodes and a pair of secondary electrodes shorted to ground and surrounding the main electrodes are disposed at roughly the center of the crystal substrate. One main electrode and one secondary electrode are used as inputs and the other main electrode and secondary electrode are used as outputs, with these two terminal pairs being used to measure and adjust a frequency.

Abstract: A piezoelectric oscillator comprising a piezoelectric vibrator with a piezoelectric vibrating element housed in a package and bottom terminals formed on the outer side of the bottom of the package, a circuit board with at least one electronic circuit component mounted and conductor patterns formed on the top side, and columnlike supports which mechanically and electrically connects the bottom terminals of the piezoelectric vibrator and the conductor patterns on the circuit board. The piezoelectric oscillator has a smaller board occupation area, and can be manufactured by quantity production using a batch process at a high productivity and a reduced cost.

Abstract: 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.

Abstract: With a surface mount SAW device constituted so that an outer surface of a SAW chip is covered with a heated and softened sheet resin, a resin is filled into skirts of the SAW chip, and so that an airtight space is thereby formed below IDT electrode on a lower surface of the SAW chip, it is possible to dispense with negative pressure suction from through holes formed in a mounting substrate so as to ensure a filling amount of the resin into gaps, and dispense with strict management of heating temperature and suction profiles.

Abstract: The present invention provides a method for making high-frequency piezoelectric resonators so that constants of the resonator can be measured precisely. A cavity is formed at a central section of an AT-cut crystal substrate. Two grooves are formed at predetermined distances from the left and right of the cavity, and two more grooves are formed at predetermined distances outward from these two grooves. Two more grooves perpendicular to the first set of grooves are formed. A pair of main electrodes and a pair of secondary electrodes shorted to ground and surrounding the main electrodes are disposed at roughly the center of the crystal substrate. One main electrode and one secondary electrode are used as inputs and the other main electrode and secondary electrode are used as outputs, with these two terminal pairs being used to measure and adjust a frequency.

Abstract: 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 TR1 and 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 TR1. Further, a base bias circuit composed of a resistor RB 1 and a resistor RB2 is connected to a base of the oscillation transistor TR1, has a piezoelectric element Xtal and a capacitor C1 inserted and connected in series between the base of the oscillation transistor TR1 and the ground, and further has a resistor Rc connected to a collector of the oscillation transistor TR1 together with the power supply voltage Vcc line, and has a capacitor Cce connected between the collector and the emitter.

Abstract: 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 circuit 12 including a crystal vibrator 11 having 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 circuit 13 that controls the current of the crystal vibrator, a temperature compensation voltage generation circuit 15 that compensates for temperature characteristics of the crystal vibrator 11, and an external variable capacitance diode 17 that changes the oscillation frequency of the oscillation circuit 12 using an external variable voltage controller 16. The vibrator current control circuit 13 comprises a variable capacitance diode 14 that controls the vibrator current, and capacitors 1 to 3.