EP0429217A2
Expired / Lapsed
EP
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Frequency synthesiser
Assignee: NORTEL NETWORKS Corp
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Filing: 1990-11-07
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Granted: —
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Expires: 2010-11-07
Abstract
Abstract A fractional-N frequency synthesiser having a programmable divider and control means therefor, wherein said control means incorporates a digital delta-sigma modulator operating as an interpolator.
Inventors
- 👤 Philip Stuart Gaskell
- 👤 Eric Breakenridge
- 👤 Nigel Jonathan Richard King
- 👤 Michael John Ball
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 02:29
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/18; H03L7/197; H03L7/1974; H03L7/1976
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
27 words
A fractional-N frequency synthesiser having a programmable divider and control means therefor, characterised in that said control means incorporates a digital delta-sigma modulator operating as an interpolator.
Claim 2
Dependent Claim
27 words
A fractional-N frequency synthesiser having a programmable divider and control means therefor, characterised in that said control means incorporates a digital delta-sigma modulator operating as an interpolator.
Claim 3
Dependent Claim
17 words
A synthesiser according to claim 1 characterised in that said delta-sigma modulator is a second-order feedback modulator.
Claim 4
Dependent Claim
24 words
A synthesiser according to claim 2 including at least one additional first or higher order loop(s) to the modulator configured in a feed-forward arrangement.
Claim 5
Dependent Claim
32 words
A synthesiser according to any preceding claim wherein the interpolator sampling frequency is a multiple of the synthesiser reference frequency, the synthesiser including means for sub-sampling the interpolator at the reference frequency.
Claim 6
Dependent Claim
47 words
A synthesiser according to any preceding claim including means for extracting an error signal from the interpolator output, means for filtering the error signal, means for converting the filtered error signal to an analogue signal and means for adding the analogue to the synthesiser phase comparator output.
Claim 7
Dependent Claim
14 words
A synthesiser according to any preceding claim wherein the synthesiser is a multiple-loop synthesiser.
References Cited (Backward Citations)
No citation records indexed.
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