Telecommunications – Receiver or analog modulated signal frequency converter – Local control of receiver operation
Reexamination Certificate
2006-04-04
2006-04-04
Vo, Nguyen T. (Department: 2685)
Telecommunications
Receiver or analog modulated signal frequency converter
Local control of receiver operation
C455S076000, C455S112000, C455S216000, C375S375000, C375S373000
Reexamination Certificate
active
07024171
ABSTRACT:
Frequency synthesizer utilizing fractional-N synthesis includes a phase detector having an input receivable of a reference frequency, a loop filter arranged to receive the signal from the phase detector, a tunable oscillator arranged to receive a tuning signal generated by the loop filter and provide an output frequency and an integer divider arranged to receive the output frequency of the oscillator, divide it by a division control number (N+F) and provide the divided output frequency to the phase detector. The division control number is made up of an integer (N) and a fraction portion (F) separated into at least two different fractions. The fraction portion is generated by at least two sigma-delta converters, each processing a respective fraction with the sigma-delta converter processing a smaller fraction being driven at a lower clock rate than a sigma-delta converter processing the largest fraction. By driving the sigma-delta converter which processes a smaller fraction at a reduced clock rate, the sigma-delta converter can consume less power and be manufactured at reduced cost.
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Chow Charles
Frishauf Holtz Goodman & Chick P.C.
ICOM America, Incorporated
Vo Nguyen T.
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