Arrangement of contact pairs for compensating near-end...

Details Arrangement of contact pairs for compensating near-end... Arrangement of contact pairs for compensating near-end...

2000-04-26

2001-11-20

Sircus, Brian (Department: 2839)

Electrical connectors

With insulation other than conductor sheath

Plural-contact coupling part

C439S941000

Reexamination Certificate

active

06319069

ABSTRACT:

FIELD OF THE INVENTION
The present invention pertains to an arrangement of contact pairs for compensating the near-end crosstalk for an electric patch plug.
BACKGROUND OF THE INVENTION
Due to a magnetic and electric coupling between two contact pairs, a contact pair induces a current or influences electric charges in adjacent contact pairs, so that side-to-side crosstalk occurs. To avoid the near-end crosstalk, the contact pairs may be arranged at very widely spaced locations from one another, or a shielding may be arranged between the contact pairs. However, if the contact pairs must be arranged very close to one another for design reasons, the above-described measures cannot be carried out, and the near-end crosstalk must be compensated.
The electric patch plug used most widely for symmetric data cables is the RJ-45 patch plug, which is known in various embodiments, depending on the technical requirement. Prior-art RJ-45 patch plugs of category 5 have, e.g., a side-to-side crosstalk attenuation of >40 dB at a transmission frequency 100 MHz between all four contact pairs. Based on the unfavorable contact configuration in RJ-45, increased side-to-side crosstalk occurs due to the design. This occurs especially in the case of the plug between the two pairs
3
,
6
and
4
,
5
because of the interlaced arrangement (e.g. EIA/TIA
568
A and
568
B). This increased side-to-side crosstalk limits the use at high transmission frequencies. However, the contact assignment cannot be changed for reasons of compatibility with the prior-art plugs. Due to this unfavorable design arrangement, special measures are needed even to reach a near-end crosstalk of >40 dB at 100 MHz of category 5. All prior-art measures leave the plug unaffected and bring about the improvement in near-end crosstalk by compensatory measures in the socket (jack).
The crossing of a pairs (pairs of conductive paths) has been used. As a result of this side-to-side crosstalk, an antiphase is generated behind the crossed area. This is also described as balancing the circuits. The conductive path of each transmission line connecting to the jack/plug (e.g. two conductive paths per transmission line—a pair) that is furthest from the adjacent pair in the jack/plug is brought together with the conductive path of that adjacent pair which is closest (a twist of the initial position). This use of conductive paths (e.g. in a circuit board) balances the reactive effect of pair interaction at the jack/plug. Crossing of the two lines
4
and
5
is described in this connection in EP 0 525 703 A1, and the crossing of the two lines
3
and
6
in WP 94/06216. The twisting of leads of different pairs has also been known from EP 0 601 829 A2. The compensation by direct auxiliary capacitances to the contact after next can be found in EP 0 692 884 A1. A solution for compensation by extended and multiply bent contacts to their crossing is described in EP 0 598 192 A1, where the compensation is generated behind the crossing by the continued contacts and insulation displacement terminals.
Compensation measures in the socket (jack) are a common feature of all the prior-art solutions, but the distance between the side-to-side crosstalk area and the effective compensation area is too great. To achieve the spring forces of the jack/socket and to securely lead the mobile contacts in the socket these contacts are made relatively long. This entails a compensation region—a crossing on a printed circuit board, on the extended stationary contacts or twisted terminal leads—used at far too great a distance. The gain from these prior-art compensation measures is therefore limited, so that patch plugs for 200 MHz cannot be prepared according to these prior-art solutions, because the near-end crosstalk cannot be sufficiently compensated at higher frequencies.
SUMMARY AND OBJECTS OF THE INVENTION
The basic technical problem to be solved by the present invention is therefore to provide an arrangement of contact pairs for an electric patch plug (jack/plug) with at least two contact pairs interlaced with one another, especially for an RJ-45 patch plug, for higher transmission frequencies with sufficient side-to-side crosstalk attenuation. Another technical problem to be solved is to provide an electric patch plug for high transmission frequencies, which is downward compatible with the prior-art category 5 patch plugs.
According to the invention, an arrangement of contact pairs for a socket (jack) of an electric patch plug is provided with at least two contact pairs interlaced with one another. This is particularly an RJ-45 patch plug, wherein the contacts can be arranged partially in a fixed manner toward the terminal area and elastically in a socket body toward the contact area. At least two contacts of the contact pairs which are interlaced with one another are crossed (the initial position is changed). The crossing point of the contacts is located in the elastically mounted partial area of the said contacts.
Due to the crossing point being arranged in the elastically mounted part of the contact of the socket, the site of the physical location of the compensation is displaced into the vicinity of the site where the near-end crosstalk is generated, namely, the contact area, so that considerably higher cutoff frequencies can be reached. The tolerances occurring due to the assembly of the wires is reduced due to the decoupled position of the contacts in the terminal area of the plug to the extent that higher transmission frequencies can be reached in conjunction with the arrangement of the contacts for the socket, but the arrangement is still also compatible with category 5. In another preferred embodiment, the crossing point is placed directly behind the contact area, which brings about a minimal distance between the side-to-side crosstalk zone and the compensation zone, so that phase shifts due to run times are negligible.
In another preferred embodiment, the contacts of the contact pairs interlaced with one another are led in parallel in the contact area, wherein the inner contacts are directed in opposite directions to the outer contacts, which brings about a decoupling of the current-carrying partial areas of the inner contacts. Adjoining this area, the inner contacts are crossed and bent by 180° and are again led in parallel to the first partial area. This causes the side-to-side crosstalk generated to change its sign directly behind the crossing point and compensation of the side-to-side crosstalk from the contact area to take place.
To generate the sufficient spring forces, the contacts of the contact pairs interlaced with one another are bent at an acute angle in the adjoining area and are led in parallel to a terminal area. For decoupling and consequently for limiting the compensation area, the inner contacts are once again bent away from the outer contacts before the terminal area and are again led in parallel to the outer contacts.
To reduce the side-to-side crosstalk from the outer contacts of the contact pairs interlaced with one another to the non-interlaced contact pairs, the latter are led in opposite directions in parallel to the inner contacts in the contact area bent into a decoupled position, and are subsequently led in parallel to the contacts of the contact pairs interlaced with one another to the terminal area.
To improve the compensation gain, the side-to-side crosstalk is deliberately selected to be greater in the plug and is subsequently again compensated, and the compensation zone is divided into two partial areas, namely, a compensation zone in the socket and a compensation zone at the terminal area of the plug, for which purpose the inner contacts are likewise crossed.
In another preferred embodiment, the inner contacts are made with a lower line impedance in the compensation zone of the plug than in the side-to-side crosstalk zone, so that a predominantly capacitive coupling, which compensates the predominant component of the capacitive coupling in the area of the plug/socket transition, where the non-current-carrying contact

Affiliated with

Also associated with

Rating

Arrangement of contact pairs for compensating near-end... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Arrangement of contact pairs for compensating near-end..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Arrangement of contact pairs for compensating near-end... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2593831