Abstract: The present invention relates to a resonance type voltage control oscillator. The voltage control oscillator includes an inductor unit including two inductances serially coupled to each other, a variable capacitance unit coupled to the inductor unit in parallel, a negative resistance unit coupled to the inductor unit in parallel, a first variable resistor having a resistance value corresponding to an input first control signal, a second variable resistor having a resistance value corresponding to an input second control signal, and a variable resistor control circuit unit generating the first and second control signals and controlling respective resistance values of the first and second variable resistors. The variable resistor control circuit unit controls the respective resistance values of the first and second variable resistors to set current flowing in the inductor unit, the variable capacitance unit and the negative resistance unit to a desired current value.

Abstract: The present invention relates to a resonance type voltage control oscillator. The voltage control oscillator includes an inductor unit including two inductances serially coupled to each other, a variable capacitance unit coupled to the inductor unit in parallel, a negative resistance unit coupled to the inductor unit in parallel, a first variable resistor having a resistance value corresponding to an input first control signal, a second variable resistor having a resistance value corresponding to an input second control signal, and a variable resistor control circuit unit generating the first and second control signals and controlling respective resistance values of the first and second variable resistors. The variable resistor control circuit unit controls the respective resistance values of the first and second variable resistors to set current flowing in the inductor unit, the variable capacitance unit and the negative resistance unit to a desired current value.

Abstract: A phase difference detection circuit that is formed by digital circuits having a small circuit area. In the phase difference detection circuit, the circuits for generating a tracking error signal are structured by digital circuits, and a digital tracking error signal TE is generated from digital signals output from comparators. The latest previous phase difference data are stored in a phase difference memory, and a phase difference window PW is defined from the average phase difference calculated from the stored phase differences.

Abstract: A phase difference detection circuit is disclosed that is formed by digital circuits having a small circuit area. In the phase difference detection circuit, the circuits for generating a tracking error signal are structured by digital circuits, and a digital tracking error signal TE is generated from digital signals output from comparators. The latest previous phase difference data are stored in a phase difference memory, and a phase difference window PW is defined from the average phase difference calculated from the stored phase differences.