Alps Electric Co., Ltd.

Kazuhiro Nakano

Isao Ishigaki

Hiroki Noumi

Isao Hasegawa

An oscillator includes an oscillator circuit which includes an oscillator transistor and a resonant circuit. The oscillator circuit can change an oscillation frequency. An amplifier circuit receives an oscillation signal output from the oscillator circuit and amplifies the oscillation signal. The resonant circuit is connected at high frequencies between the base and the collector of the oscillator transistor. The oscillation signal is output from the resonant circuit.

Oscillator for achieving stable oscillation

In a three-band switching oscillator, a switching circuit is provided to switch the operating conditions of a first and second voltage-controlled oscillator and to switch an oscillation frequency band of the first voltage-controlled oscillator. The switching circuit switches a first switch in accordance with a switching voltage inputted to a first switching terminal and switches an oscillation frequency band in accordance with a switching voltage inputted to a second switching terminal. Only when a high-level switching voltage is inputted to the second switching terminal, the second switch is placed into an open condition by a high-level switching voltage inputted to the first switching terminal and placed into a closed condition by a low-level switching voltage inputted thereto, and when a low-level switching voltage is inputted to the second switching terminal, the second switch is placed into the open condition irrespective of the switching voltage inputted to the first switching terminal.

Three-band switching oscillator suitable for size reduction

An oscillator with a buffer circuit comprises: an oscillation circuit having an oscillation transistor; and a buffer circuit which has an amplification transistor and amplifies an oscillation signal outputted from the oscillation circuit by the amplification transistor. A power supply voltage is applied to the collector of either the oscillation transistor or the amplification transistor, the emitter of the other transistor has a D.C. ground connection, and the emitter of the transistor to which the power supply voltage is applied is connected to the collector of the other transistor via a resistor.

Oscillator with buffer circuit in which deterioration in C/N ratio is lightened

An electronic unit is provided that effectively utilizes the upper surface of a circuit board as a wiring pattern and reduces the size of the electronic unit. Wiring patterns and grounding patterns are provided on the upper surface of a circuit board. The wiring patterns and grounding patterns are connected to wiring terminal electrode portions and grounding terminal electrode portions by connection conductors, respectively, provided in through-holes. This allows a cover, covering electronic parts on the circuit board, to be effectively mounted as the entire outer periphery of the first surface of the circuit board is covered.

Electronic unit effectively utilizing circuit board surface

The high frequency tuning amplifier for buffer has a tuning circuit consisting of a serial circuit of the first and second inductors connected between the output of transistor amplifying stage and the power source, a first capacitor connected in parallel to the serial circuit of first and second inductors, a serial circuit of the second and third capacitors connected in parallel to the second inductor and a switching element to which a band switch voltage is supplied, connected between the connecting point of the second and third capacitors and the reference voltage point. The tuning circuit is tuned to the high band frequency when the switching element is turned ON and to the low band frequency when the switching element is turned OFF.

High frequency tuning amplifier for buffer

An amplifier and a portable telephone apparatus using the same in which a resonance circuit is provided for each of different frequencies and bypass capacitors of the ground terminal of a transistor are properly switched according to the different frequencies. Two capacitors connected to each other in series for the parallel resonance circuits to be connected to the output terminal of the amplifying transistor are used for the resonance capacitors for the higher frequency. For the lower frequency, one of the tow capacitors that is on the ground side is used as a bypass capacitor that grounds the ground terminal of the transistor in a high frequency manner, the other capacitor being functioned as a resonance capacitor at that frequency.

Amplifier and portable telephone apparatus using the same

A laminated electronic component has a structure in which an micro-strip line (MSL) is formed in a first dielectric layer, and a first ground layer and an adjustment pattern layer are formed on the top surface and the base surface of the first dielectric layer, respectively. A second dielectric layer is formed between the adjustment pattern layer and a second ground layer, comb teeth-shaped parallel electrodes having an area larger than that of the MSL is formed at a position opposed to the MSL in the adjustment pattern layer. A slit is formed not to be opposed to the MSL in the second ground layer and to be opposed to the connection points of the parallel electrodes. By emitting a laser beam from the direction of the second ground layer through the slit and the second dielectric layer, and separating the connection points of the parallel electrodes, the capacitance between the MSL and the ground can be adjusted in steps, which increases the resonant frequency of the MSL.

Laminated electronic component with trimmable parallel electrodes

A tuning circuit is formed of inductors connected in series, voltage-controlled variable capacitance means connected in parallel to the inductors, switch means connected in parallel to one of the inductors and capacitance means connected in parallel to another of the inductors, and the resonance frequency of a resonant circuit of the inductor and the capacitance means is set higher than the resonance frequency of the tuning circuit. When the switch means is turned off to change the frequency of the -tuning circuit to the lower frequency band, the frequency variable ratio of the tuning circuit becomes large and when the switch means is turned on to change the frequency to the higher frequency band, such frequency variable ratio becomes small, and the frequency variable width of the lower frequency band can be set almost equal to the frequency variable width of the higher frequency band by adequately selecting the capacitance of the capacitance means.

Growing community of inventors

Fukushima-ken, Japan

Kazuhiro Nakano