Alps Electric Co., Ltd.

Takeshi Tanemura

Yasuhiro Ikarashi

Takehiko Sone

Kouta Iijima

An electronic circuit unit includes a substrate on which a wiring pattern is provided; electronic parts, including a semiconductor bare chip disposed on a surface of the substrate; and a soft sealing resin provided on the substrate so as to cover the electronic parts. A wire of the semiconductor bare chip is connected to the wiring pattern and is covered with the soft sealing resin and a protection member made of a resin harder than the sealing resin having an upper wall having a flat external surface and leg parts extending from the upper wall to the substrate. Since the leg parts are secured to the substrate while the protection member covers the sealing resin, the protection member can protect the sealing resin without being cracked even when external force is applied to the protection member, thereby preventing the wire from breaking.

Electronic circuit unit that is easy to manufacture and method of manufacturing the same

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.

Oscillating apparatus including two-band resonance circuit

A gain-control-type transistor power amplifier is provided which performs gain control in a state in which there is satisfactory linearity by extending the varying range of a gain control voltage capable of controlling the output level of an RF signal. The gain-control-type transistor power amplifier includes an amplifying transistor, to the base of which a bias voltage and an amplification signal are supplied, and a control transistor, to the base of which a gain control voltage is supplied. The gain control voltage output from the emitter of the control transistor is supplied to the base of the amplifying transistor in such a manner as to be superposed onto the base bias, and the base bias voltage is varied by the supplied gain control voltage, controlling the gain of the amplifying transistor and the output level of the RF signal.

Gain-control-type transistor power amplifier

A transmission control circuit for use in a TDMA communication device controls the rise and fall characteristics of driving voltages applied to high-frequency amplifier circuits in such a way that the generation of unnecessary waves at the time of transmission can be restrained to a minimum, wherein a driving voltage ON/OFF circuit B1 outputs first and second driving voltages S1 and S2 having different rise and fall time constants, the first driving voltage S1 being supplied to a first high-frequency amplifier circuit A1, and the second driving voltage S2 to a second high-frequency amplifier circuit. The requisite rise time for the driving voltage S1, which is supplied to the first high-frequency amplifier circuit A1, is longer than the requisite rise time for the ON/OFF switching signal S2, supplied to the second high-frequency amplifier circuit A2, and the requisite fall time for the driving voltage S1 is shorter than the requisite fall time for the second ON/OFF switching signal S2, which is supplied to the second high-frequency amplifier circuit A2.

Transmission control circuit for use in TDMA communication devices

A voltage controlled oscillator includes a resonant circuit formed of an impedance in series with a voltage variable capacitance. The impedance consists of a surface acoustic wave resonator in parallel with either an inductance coil or another acoustic wave resonator.

Voltage controlled oscillator including a saw resonator

A high frequency oscillator having an oscillation transistor connected to a resonant strip line unit consisting of a main strip line member and an auxiliary strip line member. The auxiliary strip line member is connected in parallel with or isolated from the main strip line member by a switch diode for switching the characteristic impedance of the strip line unit so as to generate a reception or transmission carrier wave output. A varactor diode connected to the strip line unit has its capacitance changed through an applied control voltage for channel switching. A modulating signal input terminal is directly connected to a portion of the auxiliary strip line member for modulating an FM transmission signal independently of the value of the control voltage applied to the varactor diode.

Growing community of inventors

Fukushima-ken, Japan

Takeshi Tanemura