摘要:
Ein durch Phasenvergleich eines Referenztaktsignals (rts) und eines in einem spannungsgesteuerten Oszillator (VCO) gebildeten Oszillatortaktsignals (ts) ermitteltes Vergleichssignal (vs) beeinflußt die Zählrichtung eines m-stufigen Vorwärts-Rückwärts-Zählers (VRZ1,2). Die Zählergebnisse von n-höherwertigen Zählausgängen (ZA) des Vorwärts-Rückwärts-Zählers (VRZ1,2) sowie die Zählergebnisse von n-Zählerausgängen (ZA) eines die Impulse des Oszillatortaktsignals (ts) kontinuierlich zählenden Zählers (Z) werden verglichen und in Abhängigkeit vom Vergleichsergebnis ein pulsdauer- bzw. pulspausenmoduliertes Ansteuersignal (as) erzeugt.
摘要:
A radio frequency identification (RFID) interrogator sends parameters and return link configuration information to an RFID tag. The tag uses the parameters to determine whether or not to respond with a reply signal. The tag uses the return link configuration information to select a modulation type from amongst a plurality of modulation types to modulate the reply signal.
摘要:
A dual-tracking phase-locked loop circuit is provided for moving with minimum disruption from conventional PLL operation to processor-controlled tracking of another closely related clock. In addition to conventional PLL components the circuit comprises a processor-controlled up/down counter which may operate alternatively as a link in the loop or as providing the base-line frequency determining value at the time of transition from PLL to processor-controlled tracking operation, thereby ensuring none disruptive transition.
摘要:
The subject invention is a precision controlled frequency synthesizer which is capable of precisely adjusting the frequency of an output signal to maintain a desired frequency difference between an inputand outputsignal regardless of the stability of the frequency of an input signal. The synthesizer comprises the basic elements of a phase locked loop (PLL) type circuit. The PLL circuit portion detects the actual frequency difference, a value A, between the input and output signals. One reference source provides a desired frequency difference, a value D, which represents the frequency difference between a stable input frequency and a desired output frequency. The difference between the frequency difference values A and D serves as the amount of adjustment to the frequency of the output signal. This adjustment represents the amount of compensation necessary to maintain a specified frequency relationship between the input and output signals.
摘要:
A radio frequency identification device includes an integrated circuit (16) including a receiver (30), a transmitter (32), and a microprocessor (34). The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.
摘要:
A phase-locked loop (PLL) 100, particularly useful for ADSL frequency locking applications, uses inexpensive external components in combination with versatile logic that can be implemented in a programmable logic device 102 or an application specific integrated circuit. The PLL 100 has the ability to revert to center-frequency operation in the absence of a timing reference 110 and to adapt to a variety of reference frequencies through logic selection.
摘要:
A dual-tracking phase-locked loop circuit is provided for moving with minimum disruption from conventional PLL operation to processor-controlled tracking of another closely related clock. In addition to conventional PLL components the circuit comprises a processor-controlled up/down counter which may operate alternatively as a link in the loop or as providing the base-line frequency determining value at the time of transition from PLL to processor-controlled tracking operation, thereby ensuring none disruptive transition.
摘要:
Synthétiseur de fréquence à régulation précise, capable de régler avec précision la fréquence d'un signal de sortie pour maintenir une différence de fréquence désirée entre un signal d'entrée et un signal de sortie, sans tenir compte de la stabilité de la fréquence d'un signal d'entrée. Le synthétiseur comporte les éléments de base d'un circuit du type à boucle d'asservissement de phase (PLL). La partie de circuit PLL détecte la différence de fréquence effective, une valeur A, entre les signaux d'entrée et de sortie. Une source de référence fournit une différence de fréquence désirée, une valeur D, représentant la différence de fréquence entre une fréquence d'entrée stable et une fréquence de sortie désirée. La différence entre les valeurs de différence de fréquence A et D sert d'étalon pour le réglage de la fréquence du signal de sortie. Ce réglage représente l'importance de la compensation nécessaire pour maintenir une relation de fréquence spécifiée entre les signaux d'entrée et de sortie.
摘要:
A phase-locked loop (PLL) 100, particularly useful for ADSL frequency locking applications, uses inexpensive external components in combination with versatile logic that can be implemented in a programmable logic device 102 or an application specific integrated circuit. The PLL 100 has the ability to revert to center-frequency operation in the absence of a timing reference 110 and to adapt to a variety of reference frequencies through logic selection.