Alps Electric Co., Ltd.

Akiyuki Yoshisato

Kazuhiko Ueda

Akihiko Inoue

Hiroshi Sakuma

Yasuhiro Ikarashi

Katsumi Tobita

Sadao Igarashi

Hiroyuki Ishiwata

Takashi Tanemura

Yasuhio Ikarashi

Kohta Iijima

Masami Miyazaki

Hiroaki Kukita

A diplexer contains a common terminal connected to an antenna, a first input/output terminal for inputting/outputting signals of a plurality of high frequency bands higher than a predetermined frequency, and a second input/output terminal for inputting/outputting signals of low frequency bands lower than the predetermined frequency. Between the common terminal and the first input/output terminal, a high pass filter and low trap circuits for attenuating the low frequency bands respectively are interposed in series, and, between the common terminal and the second input/output terminal, a low pass filter and high trap circuits for attenuating the high frequency bands respectively are interposed in series.

Diplexer

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

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

In a surface-mounting-type electronic-circuit unit, circuit elements, including capacitors, resistors, and inductive devices, and electrically conductive patterns connected to the circuit elements are formed on an alumina board as thin films. Semiconductor bare chips for a diode and a transistor are wire-bonded to connection lands in electrically conductive patterns. And end-face electrodes connected to grounding electrodes, input electrodes, and output electrodes of electrically conductive patterns are formed at side faces of the alumina board.

Compact, surface-mounting-type, electronic-circuit unit

An oscillator includes an oscillation circuit unit and an amplification circuit unit of the common-base type. The oscillation circuit unit includes an oscillation transistor and a resonance circuit, the collector of the oscillation transistor being grounded via a first capacitor. The amplification circuit unit includes an amplification transistor, the emitter thereof being directly connected to the collector of the oscillation transistor and the base thereof being grounded via a second capacitor. The resonance circuit is connected between the base of the oscillation transistor and the ground. An oscillation signal output from the collector of the oscillation transistor is input to the emitter of the amplification transistor while partially being bypassed to the ground via the first capacitor. Negative feedback is provided to the amplification transistor in association with the second capacitor.

Oscillator with constant output level over oscillation frequency range

The invention provides an electronic circuit unit that is suitable for miniaturization and excellent in high frequency characteristic. Capacitors and a wiring pattern are formed on an alumina substrate by means of thin film forming technique, and a part of the wiring pattern is served as the connection land for mounting a bare chip of a transistor. Among the capacitors, the top electrode of the capacitor is served also as a part of the connection land, and the bottom side collector electrode of the bare chip is connected to the connection land by use of conductive adhesive. Top electrodes of the residual capacitors are served as the bonding pad, and the base electrode and the emitter electrode on the top side of the bare chip are connected to the top electrodes of the respective capacitors by a wire.

Electronic circuit unit that is suitable for miniaturization and excellent in high frequency characteristic

To provide a surface-mounting type electronic circuit unit suitable for miniaturization, circuit elements including capacitors, resistors and inductance elements and a conductive pattern connected to these circuit elements are thinly formed on an alumina substrate, semiconductor bare chips for a diode and a transistor are bonded on a connection land of the conductive pattern via wire, an inductance element composed of a pair of conductors opposite at a predetermined interval on the aluminum board is thinly formed and a unbalance/balance converter is formed by these conductors.

Surface-mounting type electronic circuit unit suitable for miniaturization

A video clamping correction circuit for connection with a video clamping circuit for removing an energy dispersal signal in a receiver in an energy dispersal satellite communication system, comprises: a clamping circuit including a clamping capacitor and a clamping diode for producing a video output signal; and a correction circuit including a detecting resistor for detecting a clamping current flowing through the clamping diode, a first amplifier for inverting and amplifying a signal developed across the detecting resistor in proportion with the clamping current, an integrating circuit connected to an output of the first amplifier for integrating an output signal from the first amplifier, an integration correcting circuit connected to the integrating circuit for processing an integrated waveform of the output signal into approximation with a distorted waveform in the video output signal from the clamping circuit, and a circuit for adding an output signal from the integrating circuit and integration correcting circuit to the video output signal from the clamping circuit for cancelling out the distorted waveform in the video output.

Video clamping correction circuit

Improved AFC performance is achieved in a satellite dish receiver by using an indoor unit having a first intermediate frequency (IF signal) which does not include an image frequency and by using a PLL-demodulator for controlling the AFC loop.

Indoor unit of receiver for broadcasting satellite

A video clamping circuit adapted for satellite communication includes an operational amplifier for detecting the current flowing into a diode connected to the input terminal of the buffer amplifier of the circuit. The circuit further includes rectifying and smoothing elements for deriving a DC voltage from the output from the operational amplifier and adding the DC voltage to the signal of the output stage of the buffer amplifier in an anti-phase relation, so that an energy dispersal signal superimposed on a video signal is removed and waveform distortion is minimized.

Video clamping circuit

A capacitance detector for detecting a capacitance variation from a video disk and demodulating the capacitance variation into an electric signal, comprises a first block which includes a fixed oscillator, and a coupling loop comprised of a coupling coil and a coupling capacitor, the inductance of the fixed oscillator being inductively coupled with the coupling loop; and a second block which includes a disk stylus resonator having its resonance frequency varied by the capacitance variation of the video disk. A shield plate separates the first block from the second block and a coupling window is provided which inductively couples the coupling loop with the resonant inductance of the disk stylus resonator.

Capacitance detector for video disk

In an FM demodulation circuit which demodulates an FM signal by the use of a phase-lock loop constructed of a phase comparator, a loop filter and a voltage-controlled oscillator, the loop filter is a variable loop filter whose loop band width is varied in correspondence with the modulation band width and the carrier/noise ratio of the input signal by a base band processing circuit.

Phase locked loop FM demodulator with variable bandwidth loop filter

A phase-locked loop oscillator circuit having a reference signal generator, a voltage-controlled oscillator and a phase comparator comprises a second phase comparator. The first phase comparator is supplied with an output of the reference signal generator whose frequency has been lowered and also an output of the voltage-controlled oscillator whose frequency has been lowered. The second phase comparator is supplied with a signal which has been derived from an intermediate position of a higher-frequency path extending from the reference signal generator to the first phase comparator and also a higher-frequency signal which has been derived from an intermediate position of a path extending from the voltage-controlled oscillator to the first phase comparator. Outputs of the first and second phase comparators are added and applied to the voltage-controlled oscillator to reduce residual FM noise.

Phase-locked loop oscillator circuit utilizing a sub-loop with a second

In a video signal processing circuit for removing an energy diffusion signal from a broadcasting satellite signal superposed with the energy diffusion signal, a video clamp circuit including a switching circuit for pedestal clamp for the purpose of maintaining a pedestal level as the basis of the black level of a video signal and a noise detection circuit for detecting the noise contained in the video signal, whereby the output from the noise detection circuit is applied to the switching circuit for pedestal clamp so that the clamp performance of the switching circuit for pedestal clamp is reduced by means of the output of the noise detection circuit when an S/N ratio applied to the noise detection circuit is not good, thereby improving the quality of the reception picture.

Video clamp circuit

A Colpitts type quartz crystal oscillator comprises a resonant circuit consisting of two capacitors connected in series across a quartz crystal, the latter serving as an inductive element. The resonant circuit is connected between the base and collector of a transistor, with the junction of the capacitors being connected to the emitter of the transistor to provide feedback. Means are provided to increase the gain of the transistor and thereby the driving excitation of the crystal above a normal value for a brief length of time after the oscillator is initially energized.

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Soma, Japan

Akiyuki Yoshisato