Automatic control of frequency or phase Synchronisation

HELECTRICITY H03Electronic circuits H03LAUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES

H03L7/00Automatic control of frequency or phase Synchronisation

H03L7/02using a frequency discriminator comprising a passive frequency-determining element H03L7/04wherein the frequency-determining element comprises distributed inductance and capacitance H03L7/06using a reference signal applied to a frequency- or phase-locked loop H03L7/07using several loops H03L7/08Details of the phase-locked loop H03L7/0802the loop being adapted for reducing power consumption H03L7/0805the loop being adapted to provide an additional control signal for use outside the loop H03L7/0807concerning mainly a recovery circuit for the reference signal H03L7/081provided with an additional controlled phase shifter H03L7/0812and where no voltage or current controlled oscillator is used H03L7/0814the phase shifting device being digitally controlled H03L7/0816the controlled phase shifter and the frequency- or phase-detection arrangement being connected to a common input H03L7/0818the controlled phase shifter comprising coarse and fine delay or phase-shifting means H03L7/083the reference signal being additionally directly applied to the generator H03L7/085concerning mainly the frequency- or phase-detection arrangement including the filtering or amplification of its output signal H03L7/087using at least two phase detectors or a frequency and phase detector in the loop H03L7/089the phase or frequency detector generating up-down pulses H03L7/0891the up-down pulses controlling source and sink current generators H03L7/0893the up-down pulses controlling at least two source current generators or at least two sink current generators connected to different points in the loop H03L7/0895Details of the current generators H03L7/0896the current generators being controlled by differential up-down pulses H03L7/0898the source or sink current values being variable H03L7/091the phase or frequency detector using a sampling device H03L7/093using special filtering or amplification characteristics in the loop H03L7/095using a lock detector H03L7/097using a comparator for comparing the voltages obtained from two frequency to voltage converters H03L7/099concerning mainly the controlled oscillator of the loop H03L7/0991the oscillator being a digital oscillator H03L7/0992comprising a counter or a frequency divider H03L7/0993and a circuit for adding and deleting pulses H03L7/0994comprising an accumulator H03L7/0995the oscillator comprising a ring oscillator H03L7/0996Selecting a signal among the plurality of phase-shifted signals produced by the ring oscillator H03L7/0997Controlling the number of delay elements connected in series in the ring oscillator H03L7/0998using phase interpolation H03L7/10for assuring initial synchronisation or for broadening the capture range H03L7/101using an additional control signal to the controlled loop oscillator derived from a signal generated in the loop H03L7/102the additional signal being directly applied to the controlled loop oscillator H03L7/103the additional signal being a digital signal H03L7/104using an additional signal from outside the loop for setting or controlling a parameter in the loop H03L7/105Resetting the controlled oscillator when its frequency is outside a predetermined limit H03L7/107using a variable transfer function for the loop H03L7/1072by changing characteristics of the charge pump H03L7/1075by changing characteristics of the loop filter H03L7/1077by changing characteristics of the phase or frequency detection means H03L7/113using frequency discriminator H03L7/12using a scanning signal H03L7/14for assuring constant frequency when supply or correction voltages fail or are interrupted H03L7/141the phase-locked loop controlling several oscillators in turn H03L7/143by switching the reference signal of the phase-locked loop H03L7/145the switched reference signal being derived from the controlled oscillator output signal H03L7/146by using digital means for generating the oscillator control signal H03L7/148said digital means comprising a counter or a divider H03L7/16Indirect frequency synthesis H03L7/18using a frequency divider or counter in the loop H03L7/1803the counter or frequency divider being connected to a cycle or pulse swallowing circuit H03L7/1806the frequency divider comprising a phase accumulator generating the frequency divided signal H03L7/181a numerical count result being used for locking the loop, the counter counting during fixed time intervals H03L7/183a time difference being used for locking the loop, the counter counting between fixed numbers or the frequency divider dividing by a fixed number H03L7/185using a mixer in the loop H03L7/187using means for coarse tuning the voltage controlled oscillator of the loop H03L7/189comprising a D/A converter for generating a coarse tuning voltage H03L7/191using at least two different signals from the frequency divider or the counter for determining the time difference H03L7/193the frequency divider/counter comprising a commutable pre-divider H03L7/195in which the counter of the loop counts between two different non zero numbers H03L7/197a time difference being used for locking the loop, the counter counting between numbers which are variable in time or the frequency divider dividing by a factor variable in time H03L7/1972for reducing the locking time interval H03L7/1974for fractional frequency division H03L7/1976using a phase accumulator for controlling the counter or frequency divider H03L7/1978using a cycle or pulse removing circuit H03L7/199with reset of the frequency divider or the counter H03L7/20using a harmonic phase-locked loop H03L7/22using more than one loop H03L7/23with pulse counters or frequency dividers H03L7/235Nested phase locked loops H03L7/24using a reference signal directly applied to the generator H03L7/26using energy levels of molecules, atoms, or subatomic particles as a frequency reference