US5818315A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal trace impedance control using a grid-like ground plane
Assignee: Nokia of America Corp
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Filing: 1996-12-31
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Granted: 1998-10-06
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Expires: 2016-12-31
Abstract
Abstract Methods and apparatus for controlling signal line impedance in an electronic circuit board by altering the characteristics of a grid-like ground plane. The ground plane is arranged adjacent and parallel to a signal plane of the circuit board, and includes a grid-like pattern of conductors. The grid-like pattern of conductors forms a large number of grid elements. The size of the grid elements in a portion of the ground plane varies along at least a portion of the length of a corresponding signal trace of the signal plane in order to provide a desired impedance for the signal trace. The grid element size variation may be in accordance with a ramp function, a staircase function, a square wave function, as well as suitable combinations of these and other functions. This variation of grid element size in a grid-like ground plane provides cost-effective and flexible control of signal trace impedance, without requiring any alteration in signal trace or dielectric material characteristics.
Inventors
- 👤 Dheena Dayalan Moongilan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:10
CPC Classifications
H; H05; H05K; H05K9/00; H05K1/00; H05K1/02; H05K1/0213; H05K1/0237; H05K1/025; H05K1/0253; H01; H01P; H01P3/00; H01P3/02; H01P3/08; H05K1/0216; H05K1/0218; H05K1/0224; H05K1/03; H05K1/0393; H05K2201/00; H05K2201/07; H05K2201/0707; H05K2201/0715; H05K2201/09; H05K2201/09209; H05K2201/09654; H05K2201/09681
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
90 words
A circuit board comprising: a signal trace plane; and a conductive plane arranged substantially parallel to the signal trace plane and separated therefrom by a dielectric material, wherein a portion of the conductive plane corresponding to a signal trace of the signal trace plane has a grid-like pattern of conductors forming grid elements which vary in size along at least a portion of a length of the signal trace to provide a signal trace impedance which varies along the length of the signal trace in accordance with a predetermined function.
Claim 2
Dependent Claim
90 words
A circuit board comprising: a signal trace plane; and a conductive plane arranged substantially parallel to the signal trace plane and separated therefrom by a dielectric material, wherein a portion of the conductive plane corresponding to a signal trace of the signal trace plane has a grid-like pattern of conductors forming grid elements which vary in size along at least a portion of a length of the signal trace to provide a signal trace impedance which varies along the length of the signal trace in accordance with a predetermined function.
Claim 3
Dependent Claim
14 words
The circuit board of claim 1 wherein the conductive plane comprises a ground plane.
Claim 4
Dependent Claim
44 words
The circuit board of claim 1 wherein the grid elements vary in size along the length of the signal trace from a first size providing a first impedance for the signal trace to a larger size providing a higher impedance for the signal trace.
Claim 5
Dependent Claim
46 words
The circuit board of claim 1 wherein the conductors of the grid-like pattern of conductors vary in at least one of width and thickness along the length of the signal trace such that the grid elements vary in size along the length of the signal trace.
Claim 6
Dependent Claim
37 words
The circuit board of claim 1 wherein the grid elements of the conductive plane vary in size such that the signal trace impedance varies in accordance with a ramp function along the length of the signal trace.
Claim 7
Dependent Claim
37 words
The circuit board of claim 1 wherein the grid elements of the conductive plane vary in size such that the signal trace impedance varies in accordance with a staircase function along the length of the signal trace.
Claim 8
Dependent Claim
38 words
The circuit board of claim 1 wherein the grid elements of the conductive plane vary in size such that the signal trace impedance varies in accordance with a square wave function along the length of the signal trace.
Claim 9
Dependent Claim
21 words
The circuit board of claim 1 wherein the predetermined function is selected to compensate for capacitive loading on the signal trace.
Claim 10
Independent Claim
86 words
A method of controlling an impedance of a signal trace on a circuit board including a conductive plane separated from a plane of the signal trace by a dielectric material, the method comprising the steps of: arranging the signal trace to overlay a portion of the conductive plane; and adjusting an impedance of a portion of the conductive plane below the signal trace in order to provide a signal trace impedance which varies along the length of the signal trace in accordance with a predetermined function.
Claim 11
Independent Claim
86 words
A method of controlling an impedance of a signal trace on a circuit board including a conductive plane separated from a plane of the signal trace by a dielectric material, the method comprising the steps of: arranging the signal trace to overlay a portion of the conductive plane; and adjusting an impedance of a portion of the conductive plane below the signal trace in order to provide a signal trace impedance which varies along the length of the signal trace in accordance with a predetermined function.
Claim 12
Dependent Claim
13 words
The method of claim 9 wherein the conductive plane is a ground plane.
Claim 13
Dependent Claim
57 words
The method of claim 9 wherein the portion of the conductive plane is arranged in a grid-like pattern of conductors and the step of adjusting an impedance of the conductive plane to control the impedance of the signal trace further includes the step of adjusting the size of grid elements formed by the grid-like pattern of conductors.
Claim 14
Dependent Claim
64 words
The method of claim 11 wherein the step of adjusting the size of the grid elements further includes adjusting the size of the grid elements such that the grid elements vary in size along a length of the signal trace from a first size providing a first impedance for the signal trace to a larger size providing a higher impedance for the signal trace.
Claim 15
Dependent Claim
49 words
The method of claim 11 wherein the step of adjusting the size of the grid elements further includes adjusting at least one of the width and thickness of the conductors forming the grid elements such that the grid elements vary in size along a length of the signal trace.
Claim 16
Dependent Claim
47 words
The method of claim 11 wherein the step of adjusting the size of the grid elements to control the signal trace impedance further includes the step of adjusting the size of the grid elements such that the signal trace impedance varies in accordance with a ramp function.
Claim 17
Dependent Claim
47 words
The method of claim 11 wherein the step of adjusting the size of the grid elements to control the signal trace impedance further includes the step of adjusting the size of the grid elements such that the signal trace impedance varies in accordance with a staircase function.
Claim 18
Dependent Claim
48 words
The method of claim 11 wherein the step of adjusting the size of the grid elements to control the signal trace impedance further includes the step of adjusting the size of the grid elements such that the signal trace impedance varies in accordance with a square wave function.
Claim 19
Dependent Claim
27 words
The method of claim 9 wherein the adjusting step further includes the step of selecting the predetermined function to compensate for capacitive loading on the signal trace.
Claim 20
Dependent Claim
91 words
A conductive plane for use in an electronic circuit board including a signal trace, the conductive plane comprising: a grid-like pattern of conductors arranged adjacent and parallel to a signal trace plane of the circuit board and separated from the signal trace plane by a dielectric material, the grid-like pattern of conductors forming grid elements varying in size along at least a portion of a length of the signal trace to provide a signal trace impedance which varies along the length of the signal trace in accordance with a predetermined function.
Claim 21
Dependent Claim
91 words
A conductive plane for use in an electronic circuit board including a signal trace, the conductive plane comprising: a grid-like pattern of conductors arranged adjacent and parallel to a signal trace plane of the circuit board and separated from the signal trace plane by a dielectric material, the grid-like pattern of conductors forming grid elements varying in size along at least a portion of a length of the signal trace to provide a signal trace impedance which varies along the length of the signal trace in accordance with a predetermined function.
Claim 22
Dependent Claim
19 words
The conductive plane of claim 18 wherein the conductive plane serves as a ground plane in the circuit board.
Claim 23
Dependent Claim
44 words
The conductive plane of claim 18 wherein the grid elements vary in size along the length of the signal trace from a first size providing a first impedance for the signal trace to a larger size providing a higher impedance for the signal trace.
Claim 24
Dependent Claim
46 words
The conductive plane of claim 18 wherein the conductors of the grid-like pattern of conductors vary in at least one of width and thickness along the length of the signal trace such that the grid elements vary in size along the length of the signal trace.
Claim 25
Dependent Claim
37 words
The conductive plane of claim 18 wherein the grid elements of the conductive plane vary in size such that the signal trace impedance varies in accordance with a ramp function along the length of the signal trace.
Claim 26
Dependent Claim
37 words
The conductive plane of claim 18 wherein the grid elements of the conductive plane vary in size such that the signal trace impedance varies in accordance with a staircase function along the length of the signal trace.
Claim 27
Dependent Claim
38 words
The conductive plane of claim 18 wherein the grid elements of the conductive plane vary in size such that the signal trace impedance varies in accordance with a square wave function along the length of the signal trace.
Claim 28
Dependent Claim
21 words
The conductive plane of claim 18 wherein the predetermined function is selected to compensate for capacitive loading on the signal trace.
Claim 29
Dependent Claim
114 words
An electronic circuit board comprising: a signal trace plane; a plurality of integrated circuits affixed to the circuit board and having pins connected to a signal trace of the signal trace plane; and a conductive plane arranged substantially parallel to the signal trace plane and separated therefrom by a dielectric material, wherein a portion of the conductive plane corresponding to the signal trace of the signal trace plane has a grid-like pattern of conductors forming grid elements which vary in size along at least a portion of a length of the signal trace to provide a signal trace impedance which varies along the length of the signal trace in accordance with a predetermined function.
Claim 30
Dependent Claim
114 words
An electronic circuit board comprising: a signal trace plane; a plurality of integrated circuits affixed to the circuit board and having pins connected to a signal trace of the signal trace plane; and a conductive plane arranged substantially parallel to the signal trace plane and separated therefrom by a dielectric material, wherein a portion of the conductive plane corresponding to the signal trace of the signal trace plane has a grid-like pattern of conductors forming grid elements which vary in size along at least a portion of a length of the signal trace to provide a signal trace impedance which varies along the length of the signal trace in accordance with a predetermined function.
Claim 31
Dependent Claim
14 words
The circuit board of claim 26 wherein the conductive plane comprises a ground plane.
Claim 32
Dependent Claim
44 words
The circuit board of claim 26 wherein the grid elements vary in size along the length of the signal trace from a first size providing a first impedance for the signal trace to a larger size providing a higher impedance for the signal trace.
Claim 33
Dependent Claim
21 words
The circuit board of claim 26 wherein the predetermined function is selected to compensate for capacitive loading on the signal trace.
Claim 34
Dependent Claim
29 words
The circuit board of claim 29 wherein the capacitive loading on the signal trace includes capacitive loading effects of the integrated circuits having pins connected to the signal trace.
Claim 35
Dependent Claim
28 words
The circuit board of claim 29 wherein the capacitive loading on the signal trace includes capacitive loading produced by an interconnection with another element of the circuit board.
Claim 36
Dependent Claim
29 words
The circuit board of claim 29 wherein the capacitive loading on the signal trace includes capacitive loading produced by an interconnection with an element external to the circuit board.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-05 | 2002-04-06 | 2002-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-05 | 2006-04-06 | 2006-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-05 | 2010-04-06 | 2010-10-06 | $7700.00 | Window Closed / Lapsed |