Sanyo Electric Co., Ltd.

Masao Nishida

Tetsuro Sawai

Hisanori Uda

Yasoo Harada

Takayoshi Higashino

Toshikazu Imaoka

Toshikazu Hirai

Shigeyuki Murai

Keiichi Honda

A chip capacitor is arranged on a microstrip conductor forming a microstrip line. The chip capacitor has a dielectric material and electrodes provided on both ends thereof. The electrodes of the chip capacitor are connected to the microstrip conductor. A resonance frequency is decided by the length of the microstrip conductor between the electrodes of the chip capacitor, the dielectric constant and the thickness of the dielectric substrate and the capacitance value of the chip capacitor.

Integrated circuit and resonance circuit

Integrated resonance circuit consisting of a parallel connection of a microstrip line and a capacitor

In a distributed constant circuit, a first line is connected between a first node and a second node. The first node is grounded through a series connection between a first capacitor and a second line, and the second node is grounded through a series connection between a second capacitor and a third line. The parameters of the first, second and third lines and the first and second capacitors satisfy a predetermined relational expression such that characteristics equivalent to a &lgr;/4 line are obtained with respect to the frequency of a fundamental wave, and the second and third lines and the first and second capacitors respectively resonate with respect to an arbitrary frequency.

Distributed constant circuit in an amplifier

A feedback circuit is connected between a drain electrode and a gate electrode of an FET. The feedback circuit is constituted by a series connection of a feedback amount adjusting resistor and an LC series resonance circuit. The LC series resonance circuit is constituted by a series connection of a capacitor and an inductor. The capacitance of the capacitor and the inductance of the inductor are set such that the LC series resonance circuit enters a short-circuited state with respect to an m-th harmonic by resonating at the frequency of the m-th harmonic, and the LC series resonance circuit enters an opened state with respect to a fundamental wave.

Feedback circuit and amplifier and mixer comprising the same

In a distributed constant circuit, a first line is connected between a first node and a second node. The first node is grounded through a series connection between a first capacitor and a second line, and the second node is grounded through a series connection between a second capacitor and a third line. The parameters of the first, second and third lines and the first and second capacitors satisfy a predetermined relational expression such that characteristics equivalent to a .lambda./4 line are obtained with respect to the frequency of a fundamental wave, and the second and third lines and the first and second capacitors respectively resonate with respect to an arbitrary frequency.

Distributed constant circuit

A capacitor is connected between the gate of an FET and an input node, and a resistor is connected between the input node and a ground terminal, thereby preventing the FET from oscillating in a low-frequency domain. A capacitor is connected between the drain of the FET and a ground terminal, or a line and a capacitor are connected in series between the drain of the FET and a ground terminal, thereby preventing the FET from oscillating in a high-frequency domain or at a specific frequency in the high-frequency domain.

Stabilizing circuit and amplifier

A negative voltage generating circuit includes an oscillating unit constructed of a ring oscillator for outputting a pulse signal with a high frequency and a polarity inverting unit in which the pulse signal is inputted to charge negative voltage. This negative voltage generating circuit is miniaturized and outputs a stable negative voltage. Further, the negative voltage to be outputted can be controlled by varying a resistance value through a control of an FET in a voltage controlling unit.

Negative voltage genarating circuit

A communication apparatus for use in a portable telephone is disclosed which has a transmit-receive common amplifier for amplifying a transmitted signal or received signal, and a mixer for frequency-mixing the transmitted signal or the received signal with a local oscillator output, wherein connection between the mixer and an input side of the amplifier and connection between the mixer and an output side of the amplifier are made by means of respective signal-path selector switches. During reception, a deep bias is applied to an FET of the transmit-receive common amplifier to reduce current consumption, and during transmission, a shallow bias is applied to the FET of the transmit-receive common amplifier for increased output.

Communication apparatus using common amplifier for transmission and

A field-effect transistor including a first channel layer, formed in contacting relationship with a gate electrode, and a second channel layer, formed on one side or both sides of the first channel layer in non-contacting relationship with the gate electrode, the carrier concentration in the second channel layer being higher than that in the first channel layer but lower than that in high-impurity concentration active layers forming drain and source regions. The field-effect transistor employs an offset gate configuration in which the gate electrode is formed in contacting relationship with the first channel layer at a position nearer to the high-impurity concentration active layer forming the source region than to the high-impurity concentration active layer forming the drain region. A dummy gate is formed and ion implantation is performed from two different angles using the dummy gate as a mask, thereby efficiently forming the source region, drain region, and second channel layer in a sequence of successive processing steps. By combining the suitably patterned first and second ion shielding layers, the gate to source electrode spacing and the gate to drain electrode spacing are controlled by the accuracy to which the second ion shielding layer can be formed.

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Sakai, Japan

Masao Nishida