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US5376904A Expired / Lapsed US ⏱️ 0.0 years remaining

Directional coupler for differentially driven twisted line

Assignee: Nortel Networks Ltd
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Filing: 1993-05-20
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Granted: 1994-12-27
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Expires: 2013-05-20
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Abstract

Abstract An interface for differentially driven twisted pair cable provides for inductive and capacitive coupling of a differential drive signal to respective conductors of the twisted pair. Two input tracks have a terminating resistor at a far end whose value equals the characteristic impedance of the respective track. An output track having two branches provides connection at the near end to the twisted pair cable, the far ends being connected by a terminating resistor whose value is equal to the impedance of the twisted pair cable. The output branches parallel the input tracks for a coupling length L C .

Inventors

  • 👤 Larry K. Wong

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 15:45
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/48

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 235 words
An interface for differentially driven twisted pair transmission comprising: a first track having an input at one end and a first termination resistor at the other; a second track having an input at one end and a second termination resistor at the other; a third track having a first branch substantially parallel to and adjacent the first track and a second branch substantially parallel to and adjacent the second track; a non-inverting driver connected to the input of the first track; an inverting driver connected to the input of the second track; the first branch having an output at a near end adjacent to the input of the first track; the second branch having an output at a near end adjacent to the input of the second track; first and second branches having far ends connected together via a third termination resistor; the first and second termination resistors have resistance values substantially equal to a characteristic impedance of the first and second track respectively; the third termination resistor has a resistance value substantially equal to a characteristic impedance of a twisted pair cable for connection to outputs of first and second branches of the third track; and outputs of first and second branches of the third track are connected to respective wires at a first end of a twisted pair cable, wherein the second end of the twisted pair cable is connected to a comparator.
Claim 2
Dependent Claim 235 words
An interface for differentially driven twisted pair transmission comprising: a first track having an input at one end and a first termination resistor at the other; a second track having an input at one end and a second termination resistor at the other; a third track having a first branch substantially parallel to and adjacent the first track and a second branch substantially parallel to and adjacent the second track; a non-inverting driver connected to the input of the first track; an inverting driver connected to the input of the second track; the first branch having an output at a near end adjacent to the input of the first track; the second branch having an output at a near end adjacent to the input of the second track; first and second branches having far ends connected together via a third termination resistor; the first and second termination resistors have resistance values substantially equal to a characteristic impedance of the first and second track respectively; the third termination resistor has a resistance value substantially equal to a characteristic impedance of a twisted pair cable for connection to outputs of first and second branches of the third track; and outputs of first and second branches of the third track are connected to respective wires at a first end of a twisted pair cable, wherein the second end of the twisted pair cable is connected to a comparator.
Claim 3
Dependent Claim 26 words
An interface as claimed in claim 1 wherein the first track and first branch and the second track and second branch are formed in a u-shape.
Claim 4
Dependent Claim 29 words
An interface as claimed in claim 2 wherein each track and branches are formed as a series of continuous u-shapes within a rectangular area of a printed circuit board.
Claim 5
Dependent Claim 23 words
An interface as claimed in claim 3 wherein the printed circuit board includes pads for connection of the third track to a connector.
Claim 6
Dependent Claim 32 words
An interface as claimed in claim 4 including a connector mounted on the circuit board with leads connected to the pads for connection to a twisted pair cable via a mating connector.

References Cited (Backward Citations)

US3619504A Cited
US3748601A Cited
JPS526058A Cited
US4423392A Cited
JPH03283701A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-12-26 1998-06-27 1998-12-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-12-26 2002-06-27 2002-12-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-12-26 2006-06-27 2006-12-27 $7700.00 Window Closed / Lapsed

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