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US 6,269,135 B1Granted
Digital phase discriminations based on frequency sampling
AssigneeTropian, Inc.
InventorWendell Sander
Life of this patent
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AssigneeTropian, Inc.
InventorWendell Sander
Estimating the term…
The present invention, generally speaking, provides a simple, all-digital method and apparatus for determining the phase of a first clock signal relative to a second clock signal. The first clock signal may be a digital approximation of a periodic analog signal such as an RF signal. A sampling technique is employed that produces a stream of digital bits containing relative phase information. From the stream of digital bits is formed a digital word indicative of the relative phase. The digital word may be formed using a digital filter. Advantageously, an extensive body of digital filtering techniques applicable to Sigma-Delta (sometimes referred to as Delta-Sigma) A/D converters may be applied directly to the digital stream. By using an appropriately-chosen weighting function, high accuracy may be obtained.
A method of determining the phase of a first clock signal using a second clock signal, comprising:
An apparatus for determent the phase of a first clock signal using a second clock signal, comprising:
A method of producing a data stream indicative of the phase of a first clock signal using a second clock signal, comprising sampling the first clock signal in accordance with the second clock signal to form a first stream of digital bits or symbols wherein a frequency ratio of the first clock signal and the second clock signal is variable throughout a range including non-integer values, each digital bit or symbol of a sequence of consecutive digital bit or symbols representing a number of transitions n of a predetermined polarity of the first clock signal that occurred during a corresponding period in a sequence of consecutive periods of the second clock signal, such that processing of the first stream of digital bits or symbols yields as the phase a digital word.
A circuit for producing a data stream indicative of the phase of a first clock signal using a second clock signal, comprising a first input terminal to which the first clock signal is applied, a second input terminal to which the second clock signal is applied, wherein a frequency ratio of the first clock signal and the second clock signal is variable throughout a range including non-integer values, and producing as an output signal a stream of digital bits or symbols, each digital bit or symbol of a sequence of consecutive digital bits or symbols representing a number of transitions n of a predetermined polarity of the first clock signal that occurred during a corresponding period in a sequence of consecutive periods of the second clock signal, such that processing of the stream of digital bits or symbols yields as the phase a digital word.
Dependencies are inferred from the claim text.