Oscillator and data processing equipment using the same and voltage control oscillator and data processing equipment using voltage control oscillator

An oscillator comprising a variable capacitor and an inductor,

• wherein the variable capacitor has a first variable capacitor including a first capacitor bank whose capacitance value changes according to a control signal and whose frequency conversion gain increases according to increase of the capacitance value of the first capacitor bank, and
• a second variable capacitor connected to the first variable capacitor in parallel and including a second capacitor bank whose capacitance value changes according to a control signal and whose frequency conversion gain decreases according to increase of the capacitance value of the second capacitor bank,
• wherein the first variable capacitor includes a parallel capacitor comprising the first capacitor bank and a first fine adjustable capacitor,
• the second variable capacitor includes a series capacitor comprising the second capacitor bank and a second fine adjustable capacitor, and
• a capacitance value changing rate of the series capacitor according to lowering of a resonant frequency becomes larger than a capacitance value changing rate of the parallel capacitor according to lowering of an oscillation frequency.

A data processing equipment comprising:

• an oscillator;
• a low noise amplifier that amplifies a reception signal received by an antenna;
• a modulator that modulates a baseband signal to be transmitted to output two signals orthogonal to each other;
• an orthogonal modulator that is inputted with the two orthogonal signals to output an orthogonal modulation signal using a local oscillation signal outputted from the oscillator;
• a power amplifier that amplifies the orthogonal modulation signal;
• and
• a switch that supplies the reception signal from the antenna to the low noise amplifier at a time of signal reception and supplies the orthogonal modulation signal outputted from the power amplifier to the antenna at a time of signal transmission,
• wherein the oscillator comprises:
• first and second power source voltage terminals of parallel capacitor;
• first and second power source voltage terminals of series capacitor;
• an inductor connected between the first power source voltage terminal of parallel capacitor and the second power source voltage terminal of parallel capacitor;
• a parallel capacitor composed of a first capacitor bank including variable capacitors which are connected in parallel and whose capacitor values vary from small to large value according to a first control signal group and a first fine adjustable capacitor whose capacitance value varies according to a second control signal, the first capacitor bank and the first fine adjustable capacitor being connected to each other in parallel between the first power source voltage terminal of parallel capacitor and the second power source voltage terminal of parallel capacitor;
• and
• a series capacitor composed of a second capacitor bank including variable capacitors which are connected in parallel and whose capacitor values vary from small to large value according to a third control signal group and a second fine adjustable capacitor whose capacitance value varies according to the second control signal, the second capacitor bank and the second fine adjustable capacitor being connected to each other in series between the first power source voltage terminal of series capacitor and the second power source voltage terminal of series capacitor.