AU732218B3 - Multi-contact electrical connector - Google Patents

Description

Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT

(ORIGINAL)

NAME OF APPLICANT(S): ACTUAL INVENTOR(S): ADDRESS FOR SERVICE: INVENTION TITLE: Krone (Australia) Technique Pty. Limited George Georgevits DAVIES COLLISON CAVE, Patent Attorneys 1 Little Collins Street, Melbourne, 3000 "Multi-Contact Electrical Connector" Details of Associated Provisional Application(s): No(s): PQ0781/99 filed 4 June 1999 PQ0651/99 filed 28 May 1999 The following statement is a full description of this invention, including the best method of performing it known to me/us: -1- Q:\OPERXKATKRONEPE.FLE 28/4/0 Q:OPERRJCURN FOLDERS%22R8560XSOR rrp.do%-23)l/l0 -1A- MULTI-CONTACT ELECTRICAL CONNECTOR This invention relates to an electrical connector.

Crosstalk performance in an electrical connector may be improved by arranging conductive paths of the connector such that compensating impedances are introduced. For example, US patents 5,186,647 and 5,310,363 describe such arrangements.

In accordance with the invention there is provided, an electrical connector having a first set of contacts and a second set of contacts wherein each contact of the first set of contacts is connected to a corresponding contact in the second set of contacts by a conductive element, characterised in that the conductive elements are substantially arranged, over at least part of their lengths, side by side in a common general plane and the two contacts arranged immediately on either side of an innermost pair of contacts form a first pair of contacts, wherein at least one of the conductive elements of the first pair of conductive elements defines, over part of its length, a plurality of adjacent spaced conductive path portions coupled for parallel flow of signals and wherein the conductive path portions, in use, affect mutual inductance between the conductive elements.

Preferably, the first set of contacts and said second set of contacts each include 8 contacts and wherein for said innermost pair of conductive elements and each of the two outermost pairs of conductive elements arranged in said common general plane, the conductive elements in each pair are crossed.

Preferably, each plurality of adjacent spaced conductive elements are arranged on an end of a conductive element closest to the second set of contacts.

By applying the principles of the invention, the mutual inductance between the aforementioned signal path and another adjacent signal path may be effected. At least over

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intended frequency of operation, the impedance characteristics of the connector maybe 7For example, it maybe possible to better meet applicable transmission aij sted. For example, it maybe possible to better meet applicable transmission P:%OPER.KAT'KRONE6.PET 28.4 00 -2connector, so as to improve return loss or to provide crosstalk compensation. Crosstalk compensation may arise substantially solely from the presence of the mutual inductance, or from the inductance in conjunction with other compensatory mechanisms. For example, it may be used in conjunction with arrangements like those described in the above-mentioned US patents, where the layout of signal paths of-the connector is such that at least first and second ones of these which in use carry different signals define first and second pairs of sections, the sections comprising each pair being sections of the respective first and second signal paths which are in adjacent spaced generally parallel disposition, but the sections being arranged whereby the relative phase of signals in use arising as between the sections of the first pair is opposite to that in use arising in the sections of the second pair. These sections may provide compensatory capacitances. By providing the described aperture, capacitive coupling between signal paths may be reduced. This may further assist in improving crosstalk performance.

The invention is usefully applied in forming RJ type connectors having at least four conductive elements, and where signal paths presented by at least two of these have sections as last described, at least one of the conductive elements having a part defining the described plurality of adjacent spaced path portions. The at least two elements may cross over each other to configure these to define the mentioned sections. Particularly the sections may be defined by lengths of the elements which are generally in a common plane. More generally, they may be arranged such that in cross-section transverse to the directions of extent of these elements, they are disposed at locations which are in linear alignment, or at least at locations in a geometric pattern which is substantially maintained over the lepgths of the sections, the assignment of particular conductive elements to positions in the pat'.ern being varied along the lengths thereof to produce the described relative phase inversion.

In a particular embodiment, the invention provides an electrical connector having four conductive elements which each define at respective end portions thereof first and second contacts and between these an intermediate portion interconnecting the contacts, the first contacts being adjacent to form a first set and the second contacts adjacent to form a second set, sets of external conductors when connected to the sets of contacts being electrically PAPEAKAT3O2O4mfmpwdoc-15/ IM -3the plug is inserted into the socket. The contact elements define intermediate portions which extend between the respective contacts 28, The elements 12, 14, 16, 18, 20, 22, 24, 26 are arranged so that, viewed transversely to the directions of extent thereof, major parts thereof are disposed in a linear array. In Figure 2, these major parts comprise substantially all of each element, excepting only upstanding parts which define the contacts 28. Also, in Figure 2, the major parts extend more or less substantially in a common plane. It is possible to arrange the socket of a connector like that illustrated so that the portions of those major parts that define the contacts 30 extend directly into a socket like that illustrated in Figure 1, and for clarity of understanding the nature of the elements 12, 14, 16, 18, 20, 22, 24, 26 the elements are illustrated as being configured for this purpose. However, the socket 48 shown in Figure 1 is at right angles to the plane containing portions 40 of the elements 12, 14, 16, 18, 20, 22, 24, 26 adjacent to the contacts 28, and in this case, the elements 12, 14, 16, 18, 20, 22, 24, 26 are bent, approximately about the line A-A in Figure 2 through an angle of about 90 degrees so as to correctly position them in the socket. In that case, then, contacts 30 are contained in a plane correspondingly arranged at about 90 degrees to the plane containing the portions ,where these are adjacent the contacts 28.

The elements 12, 14, 16, 18, 20, 22, 24, 26 are, in usual use of the connector 8, connected to carry signals in four circuit paths 32, 34, 36, 38 as illustrated diagrammatically in Figure By this, the signal path 32 includes the two innermost elements 18, 20, the circuit path 34 the two outermost elements 12, 14 at one side of these, the circuit path 36 the two outermost elements 24, 26 at the other side thereof, and the circuit path 38 the elements 16 and 22 between, respectively, elements 14 and 18 and elements 20, 24. This arrangement is adopted according to convention in the communications industry, but is known to be troublesome in that the resultant splitting of the circuit path 38 so that it has signal carrying components (constituted by the portions 40 at least of the elements 16 and 22) which are relatively widely spaced from each other but respectively relatively close to signal carrying mponents of the other three signal paths (particularly as constituted by at least portions Q:\OPER\RJCURN FOLDERSU28MS60%SOR ,p.dc-2OIA)I -4of elements 14, 18, 20, and 24) causes, at least at relatively high signal frequencies, significant crosstalk between the circuit paths.

It is known that crosstalk arising in signals carried by circuit paths such as the signal paths 32, 34, 36, 38 which include significant adjacent spaced and parallel conductors such as is constituted by the elements 12, 14, 16, 18, 20, 22, 24, 26 may be reduced by crossing pairs of the conductors at a suitable point, such as midway therealong, or otherwise arranging these so as to present first and second pairs of sections of the circuit paths, before and after the crossover, in which cancelling signals are in use introduced by capacitive or inductive coupling. In the connector of Figure 2 this is effected by crossing the portions 40 of the inner elements 18, 20, at a crossing 60 about midway along the lengths of these elements, and by crossing the portions 40 of the elements 12, 14 and of the elements 24,26, towards ends of the portions 40 of elements 14, 24 at crossings 62, 64 positioned at locations along the lengths of the portions 40 of respective element pairs 12, 14; 24, 26, crossings 62, 64 are transversely aligned with the crossing 60 of the elements 18, There are thus defined to sides of the crossings 60, 62, 64, respectively closer to contacts S.28 and closer to contacts 30, several sets of first and second pairs of sections of the signal Spaths 32, 34, 36, 38. As between circuit path 34 and circuit path 38, a first pair of sections 34a, 38a is defined by respective adjacent sections of the element 14 of circuit path 34 and element 16 of circuit 38. A second pair of sections 34b, 38b of circuit paths 34, 38 is defined by respective adjacent sections of elements 12 and 16. Similarly, as between circuit paths 38, 32, there is defined a first pair of sections 38a, 32a, being parts of elements 16, 18, and a second pair of sections 38b, 32b being parts of elements 16, 20. As between circuit paths 32, 38 there are also defined another first pair of sections 32c, 38c, being parts of elements 20, 22, and a second pair of sections 32d, 38d, being parts of elements 18, 22. As between circuit paths 38, 36 there is defined a first pair of sections 38c, 36a, being parts of elements 22, 24 and a second pair of sections 38d, 36b, being parts of elements 22, 26. Thus, the sections of the paths comprising each pair are sections of the respective circuit paths which are in adjacent spaced generally parallel disposition, but being arranged whereby the relative phase of signals in use arising as between the sections p.PEXKA'UO205..001 pon doc- I 1 of the first pair is opposite to that in use arising in the sections of the second pair. This expedient will generally give rise to generation of anti-phase cross-talk signal components in the circuit paths and which tend to cancel, so reducing the level of crosstalk. This effect may be due to capacitive coupling between the circuit paths, although there may be relevant inductive coupling as well.

It has been found that further crosstalk compensation may be achieved by providing, in the elements 16, 22, elongate apertures 42, particularly at portions 44 thereof between the respective contacts 28 and portions 40. In particular, although the elements 14, 24 extend transversely only a short distance outwardly from the directions of extent of portions thereof, under portions 40 of elements 12, 26 as viewed in Figure 2, before reaching the respective contacts 28, the remaining elements have the mentioned portions 44 which extend between the portions 40 thereof to the respective contacts 28. Each aperture 42 is generally centrally positioned as between side edges of the respective portion 44, and occupies a substantial part of the length thereof. In an exemplary construction, where the elements 12, 14, 16, 18, 20, 22, 24, 26, were formed from electrically conductive material approximately 0.5mm thick it was found adequate to make these apertures about 5.8 mm long and about 0.8 mm in width. In this case the material of each element 16, 22 at either side of the respective aperture was thus caused to define spaced parallel signal path portions 50, 52 (Figures 3, 4) for signal flow past the aperture. In the exemplary construction mentioned, these path portions were about 5.8 mm in length and about 0.8 mm in width. The path portions were then approximately 0.4mm wide. Figure 3 shows the element 16, in the condition illustrated in Figure 2. Figure 4 shows the element 22, bent so that the contact 30 is at 900 to the portion 40, as explained previously.

The splitting of the signal paths around the apertures 42 alters the inductive coupling between circuits 32 and 38 described with reference to Figure 5. Generally, the path portions 50, 52 will be physically parallel, but this is not essential.

P: \OPERIKA13O2054ft"Mpo doe.I5/I L -6- Generally, the size of the apertures may be determined experimentally. An RJ45 connector formed as described and illustrated was found to exhibit good crosstalk performance up to 100 MHZ.

The described elements 12, 14, 16, 18, 20, 22, 24, 26 may be formed from strip material, such as by stamping, and then by bending. Particularly, blanks may be stamped out, portions of these to form the contacts 28 being bent out of the plane of the blanks, and other bending being effected as required to configure the elements. For example, the contacts 30 typically have arched portions for contacting the contact parts of a mating plug, and these may be formed by appropriate bending operations. Similarly, where the contacts are to be positioned in a plane at an angle to the plane containing the portions 40 of the elements 12, 14, 16, 18, 20, 22, 24, 26, this may likewise be effected by bending.

The blanks from which the elements 12, 14, 16, 18, 20, 22, 24, 26 are formed may be formed as a leadframe in which the blanks are substantially wholly defined but still interconnected, so that they can be handled collectively but easily separated by subsequent cutting or stamping.

While, in the described construction, the elements forming the circuits 32, 34 and 36 are crossed, an equivalent result could be achieved by having the elements in those circuits not crossed, while crossing the elements in circuit 38. Also, although each element 16, 22 has a single aperture 42, multiple apertures may be employed. They may be spaced lengthwise and/or transversely with respect to the respective element.

In embodiments of the invention, improved return loss may result from adoption of the described techniques of the invention.

The described connector is an RJ45 connector, but it will be appreciated that the invention can be applied to other types of connector, particularly to other connectors intended for use on balanced circuits. Also, although the introduced mutual inductance arising from the Z \apertures in the described elements 16,22, is for the purpose of improving the crosstalk PIPMucATW3O203ro5. A o1-/1 100 -7characteristics of the connector, such as for example to meet the requirements of the aforementioned "Category 5" standards, it may be employed generally where mutual inductance is to be introduced in a connector, for example to adjust the impedance characteristics of the connector to comply with a standard characteristic impedance, such as 100 ohms or 120 ohms.

The described arrangement has been advanced merely by way of explanation any many modifications may be made thereto without departing from the spirit and scope of the invention which includes every novel feature and combination of novel features herein disclosed.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Claims (3)

1. An electrical connector having a first set of contacts and a second set of contacts wherein each contact of the first set of contacts is connected to a corresponding contact in the second set of contacts by a conductive element, characterised in that the conductive elements are substantially arranged, over at least part of their lengths, side by side in a common general plane and the two contacts arranged immediately on either side of an innermost pair of contacts form a first pair of contacts, wherein at least one of the conductive elements of the first pair of conductive elements defines, over part of its length, a plurality of adjacent spaced conductive path portions coupled for parallel flow of signals and wherein the conductive path portions, in use, affect mutual inductance between the conductive elements.

2. The electrical connector box claimed in claim 1, wherein said first set of contacts and said second set of contacts each include 8 contacts and wherein for said innermost pair of conductive elements and each of the two outermost pairs of conductive elements arranged in said common general plane, the conductive elements in each pair are crossed.

3. The electrical connector claimed in claim 1 or claim 2, wherein each plurality of adjacent spaced conductive elements are arranged on an end of a conductive element closest to the second set of contacts. DATED this 25 January 2001 KRONE (AUSTRALIA) TECHNIQUE PTY LIMITED By its Patent Attorneys Davies Collison Cave