摘要:
A frequency calibration apparatus and method are provided. A frequency calibration method includes determining a frequency band according to results of frequency comparisons between a synchronized reference signal whose phase is synchronized to a phase of a prescale signal and a divided signal, and performing a Phase Locked Loop (PLL) operation on a reference signal and the divided signal at the determined frequency band to lock the divided signal.
摘要:
A receiver includes first switches for applying either differential signals of an oscillator or a data signal of a transmitter to down-converting mixers; a frequency conversion unit for mixing and applying to the down-converting mixers quadrature signals generated from an arbitrary clock signal generator and the oscillator, and having a PPF for changing a phase difference of I/Q signals according to a control voltage externally applied; a phase difference detection part for checking a phase difference between the I/Q signals and generating the control voltage to be applied to the PPF according to the phase difference so as to correct the phase difference; third switches for applying the data signal processed through the down-converting mixers, filters, and amplifiers to A/D converters and applying the I/Q signals having a predetermined frequency to the phase difference detection part; and a control unit for switching the first and third switches.
摘要:
A ring oscillator and a phase error calibration method are provided. The ring oscillator may include a first voltage-current converter for controlling and outputting an amount of tail current Itail according to a magnitude of a first control voltage applied in feedback in a PLL circuit; a second voltage-current converter for controlling and outputting an amount of shift current according to a magnitude of a second control voltage applied from a system phase error detector; and differential amplifiers for controlling, for output signals, a delay time of signals based on the applied tail current amount and a shift time of the signals based on the shift current amount. Thus, a phase relation between in-phase and quadrature-phase signals outputted from the ring oscillator may be controlled.
摘要:
A frequency calibration apparatus and method are provided. A frequency calibration method includes determining a frequency band according to results of frequency comparisons between a synchronized reference signal whose phase is synchronized to a phase of a prescale signal and a divided signal, and performing a Phase Locked Loop (PLL) operation on a reference signal and the divided signal at the determined frequency band to lock the divided signal.
摘要:
A receiver includes first switches for applying either differential signals of an oscillator or a data signal of a transmitter to down-converting mixers; a frequency conversion unit for mixing and applying to the down-converting mixers quadrature signals generated from an arbitrary clock signal generator and the oscillator, and having a PPF for changing a phase difference of I/Q signals according to a control voltage externally applied; a phase difference detection part for checking a phase difference between the I/Q signals and generating the control voltage to be applied to the PPF according to the phase difference so as to correct the phase difference; third switches for applying the data signal processed through the down-converting mixers, filters, and amplifiers to A/D converters and applying the I/Q signals having a predetermined frequency to the phase difference detection part; and a control unit for switching the first and third switches.
摘要:
A ring oscillator and a phase error calibration method are provided. The ring oscillator may include a first voltage-current converter for controlling and outputting an amount of tail current Itail according to a magnitude of a first control voltage applied in feedback in a PLL circuit; a second voltage-current converter for controlling and outputting an amount of shift current according to a magnitude of a second control voltage applied from a system phase error detector; and differential amplifiers for controlling, for output signals, a delay time of signals based on the applied tail current amount and a shift time of the signals based on the shift current amount. Thus, a phase relation between in-phase and quadrature-phase signals outputted from the ring oscillator may be controlled.