Alps Electric Co., Ltd.

Yasuhiro Ikarashi

Akiyuki Yoshisato

Kazuhiko Ueda

Hiroki Noumi

Senichiro Yatsuda

Yutaka Chiba

Akihiko Inoue

Hiroki Kobayashi

Takeshi Tanemura

Hiroshi Sakuma

Yoshitaka Hirose

The voltage controlled oscillator includes an oscillating transistor, and first and second inductance elements which are connected in series and provided between an output terminal of the oscillating transistor and a high frequency ground point Vcc. Oscillating signals are output from the output terminal of the oscillating transistor and a connecting point between the first inductance element and the second inductance element, respectively. The output terminal of the oscillating transistor outputs a fundamental wave having a high level, and the connecting point between two inductance elements outputs the harmonic wave, suppressing the fundamental wave.

Voltage controlled oscillator for frequency synthesizer

The voltage controlled oscillator contains a circuit board having a laminate of a plurality of insulating plates, a wiring pattern formed on a surface of the circuit board, an electronic part mounted on the surface of the circuit board, a resonance strip line provided on an inner layer of the circuit board, and a ground pattern formed on an inner layer of the circuit board which is disposed between the wiring pattern and the strip line. Further, a conductor-deleted portion of the ground pattern faces the vicinity including a portion having a high current density in the strip line. Thus, reductions of inductance and Q are small. In addition, a portion of the strip line is shielded by means of the ground pattern with respect to the wiring pattern.

Voltage controlled oscillator small in reduction of inductance and Q

The invention provides a surface mounting type electronic circuit unit that is suitable for miniaturization. Thin film circuit elements including capacitors, resistors, and inductance elements are formed on an alumina substrate, a semiconductor bare chip of a diode and a transistor is fixed by means of wire bonding, and part of the capacitors is formed non-rectangular having rectangles projected from one side of another rectangle.

Electronic circuit unit suitable for miniaturization

A computer of the present invention contains: a CPU; plural peripheral devices controlled by the CPU; a data transmission bus between the CPU and the peripheral devices and between the peripheral devices; and a clock signal source for supplying clock signals for CPU operation and data transmission. The clock signal source contains a PLL synthesizer, and two clock signals (one for the CPU and the other for the bus) are outputted from the PLL synthesizer to stop unnecessary signals (other than the clock signals) from being produced.

Computer containing clock source using a PLL synthesizer

A clock signal supply circuit includes a sine wave oscillator and a circuit operating with an oscillation signal, as a clock signal, outputted from the sine wave oscillator, a waveform shaping circuit is provided correspondingly to the circuit, the circuit and the waveform shaping circuit are constructed in the same circuit unit, and the oscillation signal is converted into a rectangular wave by the waveform shaping circuit in the circuit unit and is supplied to the circuit.

Clock signal supply circuit with odd harmonic leakage prevention feature

A buffer amplifier is provided which includes an amplifying transistor, an inductance element for feeding power to the collector of the amplifying transistor from a power supply, a resistance attenuator having an input end, an output end, and a ground end, and an output terminal connected to the resistance attenuator. The input end of the resistance attenuator is directly connected to the collector of the amplifying transistor. The ground end is connected to the power supply. The output end is connected to the output terminal through a coupling capacitor.

Miniaturized buffer amplifier and electronic circuit unit using same

The invention provides a surface mounting type electronic circuit unit that is suitable for miniaturization and is suitable for simple output adjustment. Circuit elements including capacitors, resistors, and inductance elements and a conducting pattern connected to the circuit elements are formed on an alumina substrate by means of thin film forming technique, and a diode D and a semiconductor chip of a transistor are fixed to a connection land of the conducting pattern by means of wire bonding, wherein only the emitter resistor out of the base bias voltage dividing resistors and the emitter resistor of the transistor is trimmed for output adjustment.

Electronic circuit unit that is suitable for miniaturization and suitable for simple output adjustment

A voltage controlled oscillator comprises an oscillation transistor, a varactor diode, a resonance circuit which is coupled to the oscillation transistor, and a switching diode which changes over a resonance frequency of the resonance circuit, wherein the resonance circuit includes a first strip conductor which is served for grounding a cathode of the varactor diode in terms of direct current and a second strip conductor which is served for coupling a cathode of the varactor diode with the oscillation transistor, the switching diode is connected to the first strip conductor in parallel in terms of high frequency and has a cathode thereof grounded, and a control voltage which is served for changing a capacitive value of the varactor diode is applied to a connection point between the cathode of the varactor diode and the second strip conductor through a choke inductor.

Voltage controlled oscillator with enhanced sensitivity of change of oscillation frequency

A dual-band oscillator includes a first oscillation circuit and a second oscillation circuit. A first emitter bias resistor for setting the emitter current of a first oscillation transistor in the first oscillation circuit is provided between the emitter of the first oscillation transistor and a second inductance element in the second oscillation circuit. A second emitter bias resistor for setting the emitter current of a second oscillation circuit in the second oscillation circuit is provided between the emitter of the second oscillation transistor and a first inductance element in the first oscillation circuit.

Dual-band oscillator for preventing reduction in oscillation power caused by bias resistor

A voltage controlled oscillator includes an oscillating transistor having a collector coupled to ground at high frequencies. A first end of a microstrip is coupled to a base of the oscillating transistor by a first varactor diode. A second end of the microstrip is coupled to a second varactor diode. The length of the microstrip is about &frac12; to about &frac34; of the wavelength of an oscillation frequency.

Voltage controlled oscillator for oscillating signals with high C/N ratio

In a voltage controlled oscillator for switching oscillation frequency bands by supplying a band switching signal to an LC resonator circuit that is connected in a phase locked loop having a phase comparator and a loop filter and sets oscillation frequencies, the LC resonator circuit includes at least two inductor elements the connection and non-connection of a part of which are switched in response to a band switching signal and a capacitor element in which a voltage variable capacitor element whose capacitance value is adjusted in response to the control voltage from the loop filter is connected in series to impedance elements acting as a composite element that exhibits a capacitance value in oscillation frequency ranges. With this arrangement, when an oscillation signal is selectively output in a high or low frequency band by switching the LC resonator circuit, the voltage controlled oscillator can increase the difference between the rates of change Kv in the high and low frequency bands.

Voltage controlled oscillator

There is provided a voltage-controlled oscillator which prevents generation of an irregular oscillation signal, reduces the number of parts including large size elements, realizes reduction in size of structure and easily adjusts output level of the oscillation signal. An oscillating transistor which operates in a grounded base system to output an oscillation signal, an amplifying transistor which operates in a grounded emitter system to amplify the oscillation signal and a resonance circuit connected to the collector of the oscillating transistor are provided. The resonance circuit is provided with a resonance micro-strip line with an intermediate tap connected in a DC circuit provided between the collector of the oscillating transistor and the emitter of the amplifying transistor and a resonance capacitor connected between the collector of the oscillating transistor and the ground point, and a coupling capacitance to transmit the oscillation signal is connected between the intermediate tap of the resonance micro-strip line and the base of the amplifying transistor.

Voltage-controlled oscillator preventing irregular oscillation

The two-band oscillating apparatus of the present invention comprises in one aspect a first oscillator for outputting an oscillation signal of a first frequency band, a second oscillator for outputting an oscillation signal of a second frequency band which is higher than the first frequency band, and a grounded-emitter type amplifier including an amplifying transistor to amplify the oscillation signal of the first frequency band or the oscillation signal of the second frequency band. In this structure, an emitter bias resistor is connected between the emitter of the amplifying transistor and the ground. A first series resonance device which resonates in almost the first frequency band, and a second series resonance device which resonates in almost second frequency band, are connected between the emitter and ground. Thereby, the number of parts can be reduced through simplified structure. The amplification degree may be increased within two oscillation frequency bands without changing the amplifying characteristic.

Growing community of inventors

Fukushima-ken, Japan

Yasuhiro Ikarashi