Nihon Dempa Kogyo Co., Ltd.

Other

Saga University

Masayoshi Aikawa

Takeo Oita

Fumio Asamura

Eisuke Nishiyama

Takayuki Tanaka

Manabu Ito

Minoru Fukuda

Hiroyuki Mitome

Yuichi Sato

Akihiro Nakamura

Kozo Ono

Hiroaki Mizumura

Kenji Kawahata

Takehito Ishii

Katsuaki Sakamoto

Yoshifumi Kawamura

Takaaki Ishikawa

Kozo Egashira

Nobuyuki Kanazawa

Yoshinori Ishito

The present invention relates to an oven controlled crystal oscillator that can obtain stable oscillation frequency by reducing a temperature change in an oscillation element. The oven controlled crystal oscillator comprises; a heat-conducting plate mounted on one surface of a circuit board, a crystal resonator mounted on a surface of the heat-conducting plate opposite to the surface of the circuit board, an oscillation element constituting an oscillation circuit together with the crystal resonator, and a thermistor that detects temperature of the crystal resonator, a heating resistance which heats the crystal resonator, and a temperature control element including at least a power transistor, to constitute a temperature control circuit together with the thermistor and the heating resistance. In the oven controlled crystal oscillator, two or more open areas communicating with the heat-conducting plate at least in the thickness direction thereof are formed on the periphery of the heat-conducting plate at positions point-symmetric with respect to the crystal resonator, and one or more of each of the power transistor and the heating resistance are arranged in the same number in all of the open areas.

Oven controlled crystal oscillator

A temperature controlled oscillator is provided with a circuit substrate having a crystal resonator, an oscillating circuit, and a temperature control circuit, arranged on one or both principal surfaces, and a container main body that accommodates the circuit substrate and has mount terminals on an outer bottom surface thereof. The temperature control circuit includes at least a first temperature sensor that detects an operating temperature of the crystal resonator, a second temperature sensor that detects a surrounding temperature of the container main body, and a heating resistor that applies heat to the crystal resonator, and lead wires extend from the circuit substrate and are connected electrically to the mount terminals. An insulation groove that passes through the circuit substrate in a thickness direction is formed between: a first lead wire closest to the second temperature sensor, and the second temperature sensor; and the heating resistor.

Temperature controlled crystal oscillator

In a concentration sensor using a piezoelectric piece, for instance, a quartz piece in which the natural frequency is varied by adsorption of a sensing target, the object of the present invention is to make the concentration sensor applicable to various fluids to be measured different in viscosity while restricting consumption of the oscillation energy due to interelectrode capacitance, and to be able to cope with plural types of concentration sensors while using a common oscillation circuit. As a concrete means for solving the problem, an inductor is connected in parallel to the piezoelectric piece, and its inductance value is determined based on the relation between inductance values and oscillation loop gains in a gap between the inductance value Lmax canceling the interelectrode capacitance in a resonance frequency of the piezoelectric piece and the inductance value Lmin evaluated as the minimum value among the inductance values with which the piezoelectric piece can oscillate in a state of being immersed in a measuring fluid.

Concentration sensor and concentration detector

A crystal oscillator in which a temperature characteristic of an oscillation frequency is improved to omit a measurement operation of the temperature characteristic of the oscillator, and manufacturing is facilitated to reduce a manufacturing time. In the crystal oscillator, a power voltage is applied to a collector of a transistor via series connection of an inductor for resonance and a resistance, a crystal unit is disposed in a loop which returns to an emitter of the transistor from a point between the inductor Land the resistance, and further, in the loop, a first parallel circuit in which a stationary capacitor having a negative temperature coefficient and a stationary capacitor having a zero temperature coefficient are connected in parallel with each other is inserted between an oscillation output taking point and the collector.

Crystal oscillator

The crystal oscillator device for simultaneously generating oscillator signals with a plurality of oscillation modes of a crystal unit, comprising: a primary resonator unit filtering the oscillator signal with a primary oscillation mode, which is one of the oscillation modes, from the output of the crystal unit, a secondary resonator unit filtering the oscillation signal, bearing a different resonance frequency from that of the primary resonator unit, with the primary oscillation mode from the output of the crystal unit, a primary phase synthesis unit, synthesizing the phases of the output signal of the primary resonator unit and the output signal of the secondary resonator unit, a tertiary resonator unit, a quaternary resonator unit, and a secondary phase synthesis unit.

Crystal oscillator device, oscillation method and heater

A crystal oscillation circuit can correctly suppress the resonance of a B mode, thereby correctly excite the resonance of a C mode. Since the crystal oscillation circuit uses a quartz oscillator of an SC cut or an IC cut, the B mode (unnecessary mode) frequency is close to the C mode (main mode) frequency. Therefore, a C mode resonance circuit (main mode resonance circuit) for passing a C mode frequency and a trap circuit for suppressing the oscillation at an unnecessary mode frequency are provided in the feedback loop of the crystal oscillation circuit.

Crystal oscillation circuit

A synchronous signal generator according to the present invention outputs a pulse with low jitter by setting the sine wave output of a crystal oscillator close to an ideal sine wave, and converting it into a pulse signal. By passing the sine wave output from the crystal oscillator of an oscillation frequency f through a filter unit having an equal center frequency f, inputting output of a filter unit into a pulse converter, and converting the result into a pulse of a rectangular waveform, thereby obtaining an output signal. By configuring the filter unit by the crystal filter and setting it equal to the crystal oscillator in frequency-temperature characteristic, an output signal can be obtained with low jitter although the temperature changes.

Synchronous signal generator using a crystal oscillator and filter

A slot-line planar antenna has a substrate, an outer conductor disposed on one principal surface of the substrate and having an opening defined therein, an inner conductor disposed on the one principal surface of the substrate and positioned within the opening, the outer conductor and the inner conductor jointly defining a looped aperture line therebetween, and an electronic device electrically interconnecting the outer conductor and the inner conductor for controlling an electromagnetic wave field of a slot line provided by the aperture line.

Planar antenna with slot line

A push-push high frequency oscillator comprises a pair of amplifiers for oscillation, a loop-shaped microstrip line for connecting inputs of the pair of amplifiers to each other and connecting outputs of the pair of amplifiers to each other, a slot line disposed between the inputs and the outputs of the pair of amplifiers for electromagnetically coupling with the microstrip line, a nonlinear circuit for enhancing the level of harmonic components in an applied synchronization signal, a coupler circuit for electromagnetically coupling the output of the nonlinear circuit to the microstrip line, and a filter circuit disposed at the output of the nonlinear circuit. The filter circuit filters harmonic components of the synchronization signal such that the two oscillation systems are injected with the same frequency components as the fundamental wave or frequency components twice as high as the fundamental wave to increase frequency stability.

Injection locked high frequency oscillator

A planar harmonic high frequency oscillator comprises a pair of amplifiers for oscillation, a micro-strip line for connecting between inputs of the pair of amplifiers and between outputs of the amplifiers, a slot line disposed between the inputs and the outputs of the pair of the amplifiers for electromagnetically coupling with the micro-strip line, an output line connected to the micro-strip line at a position at which the micro-strip line traverses the slot line between the inputs or outputs of the pair of amplifiers, and an electronic device for connecting conductors on both sides of the slot line, and for controlling an electromagnetic wave field of the slot line in response to a control signal applied thereto. Two oscillation systems which oscillate in opposite phases with respect to the fundamental wave of oscillation are formed to generate an even-order harmonic of the fundamental wave.

Planar high frequency oscillator

A high frequency oscillator comprises a transmission line resonator having a midpoint which serves as a null potential point, a pair of active devices for oscillation respectively connected to a pair of mutually opposite-phase resonance wave points for the transmission line resonator, and a plurality of output lines each having one end connected to the transmission line resonator at a point symmetric to the midpoint, and the other end commonly connected to a connection. The pair of active devices share the resonator and oscillate in opposite phases to each other. The plurality of output lines are coupled to the transmission line resonator respectively at maximum displacement distribution points for a standing wave of an 2n-th harmonic in the transmission line resonator, where n is an integer equal to or larger than two. Even-order harmonic components of 2(n&#x2212;1)-th or lower are suppressed at the connection.

High frequency oscillator using transmission line resonator

A planar array antenna using a multi-layer substrate having an intermediate layer conductor in a laminated face comprises: four pieces of planar antenna elements disposed at each of geometrically square shaped apexes; first and second slot lines formed in the intermediate layer conductor, and intersecting each other; first to fourth microstrip lines formed along each side of geometrical squares so as to be coupled to each antenna element, and at the same time, electromagnetically coupled to first and second slot lines at both ends of these slot lines; and fifth and sixth microstrip lines, the top end sides thereof traversing the first and second slot lines, respectively, so as to be electromagnetically coupled to the first and second slot lines.

Planar array antenna

A crystal oscillator of the present invention includes: a substrate provided in a package; a heating device arranged as surrounding an internal area of the substrate on at least one of the surfaces of the substrate; a crystal resonator or a crystal element and an oscillation circuit unit provided in an area enclosed by the heating device; a thermosensitive element which detects a temperature in an area enclosed by the heating device; and a control unit for controlling a heating value applied to the heating device based on a detection result of the thermosensitive element.

A high frequency oscillator which obtains an oscillation output by combining the outputs of two oscillators has a substrate, first and second amplifiers for oscillation so disposed that their output ends be opposite each other, first and second signal lines each configuring a closed oscillation loop by connecting the input ends and the output ends of the first and second amplifiers, respectively, these being disposed on a first principal surface of the substrate, and a grounding conductor disposed on a second principal surface of the substrate and configuring a strip line together with each of the signal lines. An opening, where the grounding conductor is removed, is bored in the second principal surface and a coplanar line structure is configured by arranging the first and second signal lines close to each other in the area of the opening.

High frequency oscillator

A high frequency oscillator has a substrate, a resonator circuit which is disposed on one principal surface of the substrate and consists of a closed loop-shaped slot line including an inner conductor and an outer conductor, an electric boundary point set on the slot line, a two-port negative resistance element for connecting between the inner conductor and outer conductor, and an output line electrically connected to the slot line. The electric boundary point is set by connecting, for example, a stub to the resonator circuit. The stub functions as an electrically short-circuited end or an electrically open end. A Gunn diode is preferably used for the negative resistance element, and inserted at a position of the slot line resonator circuit at which impedance matching is achieved.

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Saitama, Japan

Takeo Oita