Miscellaneous active electrical nonlinear devices – circuits – and – Specific identifiable device – circuit – or system – Unwanted signal suppression
Patent
1997-11-25
1999-06-01
Le, Dinh
Miscellaneous active electrical nonlinear devices, circuits, and
Specific identifiable device, circuit, or system
Unwanted signal suppression
327552, 327113, 327117, 327100, 377 48, 36472401, 375200, H03D 104
Patent
active
059091444
ABSTRACT:
A clock reference frequency is digitally derived from a base signal, then digitally modulated by ramping the clock reference frequency up and down about a desired frequency. The modulation occurs in periodic fashion at a prescribed modulation frequency. Such modulation spreads the electromagnetic energy of the system signals over a band that is a portion of the desired clock frequency. As a result, energy in harmonics of the respective system signals also are spread. When the energy spreading of any system signal or harmonic of such signal occurs over a bandwidth greater than the 120 kHz bandwidth of conventional communication receivers, adverse EMI emissions are reduced.
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NE/SE564 Phase-Locked Loop Product Specification; Philips Semiconductors--Signetics Linear Products, 1992.
Brown Preston D.
Puckette Robert B. E.
Hewlett--Packard Company
Le Dinh
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