Alps Electric Co., Ltd.

Toshio Aota

Toshiki Baba

A voltage-controlled-oscillator with a modulator, comprising a first variable capacitance diode, a second variable capacitance diode, and a third variable capacitance diode. The second variable capacitance diode is connected in series with the third variable capacitance diode to form a serial connection member. The first variable capacitance diode is connected in parallel to the serial connection member to form a resonance device, wherein capacitance of the first variable capacitance diode is controlled by applying an oscillation frequency control voltage to the first variable capacitance diode, and capacitance of the second variable capacitance diode is controlled by applying a modulation signal to the second variable capacitance diode, and capacitance of the third variable capacitance diode is controlled in a reverse direction to changes in the capacitance of the first variable capacitance diode by applying a reverse bias voltage and the oscillation frequency control voltage to the third variable capacitance diode to thereby provide a frequency modulated wave.

Voltage-controlled-oscillator with modulator

A voltage-controlled-oscillator with a modulator, comprising a first variable capacitance diode and a second variable capacitance diode. The first variable capacitance diode is connected in series with the second variable capacitance diode to form a resonance device, wherein capacitance of the first variable capacitance diode is controlled by applying a reverse bias voltage and an oscillation frequency control voltage to both ends of the first variable capacitance diode, and capacitance of the second variable capacitance diode is controlled in a reverse direction to changes in the capacitance of the first variable capacitance diode with respect to the oscillation frequency control voltage by applying the oscillation frequency control voltage and a modulation signal to both ends of the second variable capacitance diode to thereby provide a frequency modulated wave.

A crystal oscillator circuit that is temperature compensated over a broad temperature range has a crystal oscillator, a reactance compensation circuit for providing temperature compensation at low temperatures, and a control voltage-generating circuit for providing temperature compensation at high temperatures. The reactance compensation circuit includes the parallel combination of a thermistor and a variable-capacitance diode, and this parallel combination is connected in series with the crystal oscillator. The control voltage-generating circuit includes a thermistor and transistors and applies a voltage corresponding to the ambient temperature to the variable-capacitance diode of the reactance compensation circuit.

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Soma, Japan

Toshio Aota