High bandwidth connector

Male or female connector having at least one pair of pins for a two-wire, high-speed link. The connector comprises two parallel pins, an insulating insert, a metal casing and a connection printed circuit.

This is a 371 national phase application of PCT/FR2007/051144 filed 20 Apr. 2007, which claims priority to French Patent Application No. FR 06/51397 filed 21 Apr. 2006, the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a connector capable of being used in cable links that are high speed and designed to apply a minimum of interference to the signals transferred. The invention also relates to a pair of connectors, respectively of the male and female type, capable of interacting in a satisfactory manner in a high speed link.

BACKGROUND OF THE INVENTION

When it is desired to produce digital links comprising cables capable of carrying digital information at high speed (typically more than 100 Mbits/s) there is the problem of connecting such a cable, either to another similar cable, or to an electronic processing system, with the aid of powerful connectors designed not to adversely affect the quality of the transmitted signals. A shielded, two-wire transmission line, usually recommended for such signals, requires specific, high-performance connectors. They must for example provide good protection against external electromagnetic interference. They must also interfere as little as possible with the predetermined constant impedance of the transmission lines. It should be noted that shielded, two-wire cables used for these high speed links have a constant, characteristic impedance, for example of 100 ohms. The connector must be designed so that this impedance does not vary significantly at the coupling. The cables must notably be coupled, for example by soldering, in a sufficiently simple, reliable and repetitive manner, without requiring a particular skill of the technician responsible for assembling the cable and the connector, typically by solders.

SUMMARY OF THE INVENTION

The invention makes it possible to achieve these objectives, notably the coupling at constant impedance.

More particularly, the invention relates to a connector suitable for at least one two-wire, high-speed, shielded transmission line with a predetermined constant impedance, characterized in that it comprises in combination:two parallel pins,an insulating insert in which said pins are mounted,a metal casing comprising a sleeve open at one of its ends, said sleeve housing said insert and said pins, anda connection printed circuit installed in said casing, coupled to said pins and configured to control the connection geometry of said two-wire line in said casing.

The type of connector defined above may advantageously be obtained by an appropriate modification of a connector satisfying the MIL standard DTL 83513. This standard defines a type of connector known in the prior art as a “micro-D” connector.

Notably, the polarization is obtained by the D-shape of the metal sleeve of the casing of the connector, housing the pins.

The printed circuit mentioned above makes it possible to couple the shielded cables while complying with the impedance-matching, particularly the separation of the two wires and making the soldered connections easy.

Advantageously, said printed circuit included in the casing comprises two parallel tracks, substantially in the extension of the two pins. The latter are respectively coupled to first ends of these two tracks while the ends of the two-wire line (the cores of the two shielded wires) are designed to be soldered to second ends of these two tracks, respectively.

According to another advantageous feature, said printed circuit comprises a third track perpendicular to said two parallel tracks and in the vicinity of said second ends of the latter, for the coupling of the or each sheath for shielding said shielded two-wire line.

A ground plane may advantageously be provided on the other face of the printed circuit to obtain the designed impedance between the two parallel tracks.

The invention also relates to a pair of connectors, each according to the preceding description, one comprising at least one pair of male pins and the other comprising at least one pair of female pins.

Advantageously, and in a manner known per se, one of the connectors comprises an aforementioned metal sleeve called “outer sleeve”, of larger section than that of the corresponding metal sleeve of the other connector called the “inner sleeve”, so as to slide along the latter, when the two connectors are coupled.

According to another advantageous feature, said outer sleeve is sufficiently long for its free end to come into electrical contact with a socket of the connector comprising said inner sleeve. This considerably enhances the quality and continuity of the protective shielding against the external electromagnetic fields, obtained by assembling the two casings. The quality of the electrical contact is ensured by a mechanical locking between the two casings, after electrical coupling, preferably by means of screws and nuts.

DETAILED DESCRIPTION

FIG. 1represents a connector11making it possible to couple two high-speed, two-wire transmission lines13,14. This connector is capable of being coupled either to a similar connector, for example in order to extend said lines, or to a fixed connector, installed in an electronic apparatus processing data carried by these lines.

According to the example, each transmission line13,14consists of a conventional cylindrical shielded cable enclosing two insulated conductor wires16,17mounted in a twisted manner in a common braided metal sheath20. The sheath is itself surrounded by an insulating sleeve21. The drawings illustrate the connectors already coupled to the transmission lines.

The two shielded cables are themselves surrounded by a metal braid22electrically connected to the metal casing23of the connector by means of a metal tube24comprising a shoulder24aengaged in a recess of the casing. The braid is swaged onto this tube.

Each shielded, two-wire transmission line13,14described above has a predetermined constant impedance, for example of 100 ohms.

As can be see inFIG. 1, the metal casing23consists of two assembled portions, a first portion23asupporting the interconnection components and a second portion23bforming a cover.

For each two-wire line, the connector comprises:two parallel pins (which may be male pins25aor female pins25b)an insulating insert26aor26bin which said pins are mounted,a metal sleeve30aor30b(forming part of said first portion of the casing) open at one of its ends and housing said insert and said pins.

These elements are clearly visible inFIGS. 2 and 3.

In addition, the casing23houses (for each two-wire line) a connection printed circuit32placed between said pins25aor25binstalled in a sleeve30aor30band said corresponding shielded, two-wire transmission line.

The structure of this connection printed circuit32makes it easier to couple the shielded cable. It also makes it possible to control the geometry of the two-wire line through said casing, that is to say between the cable and the two corresponding parallel pins.

Each sleeve30aor30bhouses an insert26aor26bwhich comprises only two parallel pins.

In the example ofFIG. 1in which the connector is designed for the coupling of two two-wire lines, the casing comprises two sleeves30aand consequently houses two inserts26a(situated in the sleeves) and two printed circuits32. Each printed circuit comprises two parallel tracks34arranged substantially in the extension of the two pins25aand said pins are respectively coupled to first ends35of these two tracks. The ends of the two-wire line13or14may therefore be soldered to second ends36of these two tracks, respectively. In addition, the printed circuit comprises a third track39perpendicular to said two parallel tracks and in the vicinity of said second ends36of the latter. This third track makes it possible to connect the shielding sheath20, by a simple solder.

The arrangement of the two parallel tracks34and of said third track39perpendicular to the latter makes the cabling of the two-wire line easier, as shown. In addition, the printed circuit is mounted in a housing defined in said first portion of the casing23a, immediately next to the rear ends of said pins25aor25band the latter are directly soldered to said parallel tracks. The dielectric characteristics of the insert26aor26band of the insulating support of the printed circuit32and the distance separating the pins and the two parallel tracks influence as small as possible a characteristic impedance variation in the connector.

The outer shielding formed both by the braid22and by the structure of the metal casing23protects the two-wire transmission lines from the external electromagnetic radiation and from the possible interference due to these lines. The two portions23aand23bcomprise grooves27making it possible to install seals (not shown). These elastomer seals may be filled with conductive material to increase the effectiveness of the shielding.

In the example shown, each printed circuit32is of the two-sided type so that it comprises a ground plane42extending substantially over the whole of its surface. This ground plane is defined on the other side of the printed circuit; it therefore extends parallel to said tracks34,39.

Said third track39is connected to the ground plane42, for example via a join43or a plated through-hole extending through the insulation of the printed circuit. The ground plane is, in this example, connected to the metal casing23.

At least one and preferably each metal sleeve30aor30bdefined in said first portion of the casing has a polarizing contour. In the example specifically described, said contour is D-shaped, known per se. If the connector comprises several sleeves in line, two adjacent sleeves have their contours inverted (seeFIGS. 4 and 5) which makes it possible to reduce the width of the connector.

In a connector according to the invention, the two pins may be of the male or female type and, naturally, the invention also relates to a pair of connectors, each according to the foregoing description, in which one connector comprises a pair of male pins25aarranged in the or each sleeve30aof the corresponding metal casing and the other connector comprises a pair of female pins25barranged in the or each sleeve30bof the other metal casing (FIGS. 2 and 3).

Advantageously, one of the connectors comprises at least one aforementioned metal sleeve called the outer sleeve, (the sleeve30bin this instance) with a larger section than that of the or each sleeve, called the inner sleeve (the sleeve30ain this instance), of the other connector, so as to slide along the latter when the two connectors are coupled. This is more particularly illustrated inFIGS. 2 and 3.

In addition, according to an advantageous feature of the invention, the outer sleeve30bis sufficiently long for its free end44to come into electrical contact with a socket46of the connector comprising the inner sleeve30a(FIGS. 2 and 3).

It should be noted that, with reference to the MIL standard DTL 83513 defining the general architecture of a “micro D” connector, the latter does not promote this end electrical contact.

Said end electrical contact, made possible and consolidated by screws for assembling the two connectors, considerably enhances the electromagnetic compatibility (EMC or “RFI/EMI protection”) of the high-speed connection.

In this embodiment, the female pins25bprotrude from the corresponding insert26binto an open cavity45delimited by the sleeve30bwhich surrounds them. The latter is the outer sleeve.

In addition, the male pins25aare fully integrated into the corresponding insert26aof the sleeve30aand the latter is the inner sleeve. As can be seen inFIG. 2, each male pin25aextends axially into a hole47of the insert26aand the diameter of this hole is just sufficient to accommodate the corresponding female pin25aof the other connector.

This arrangement is advantageous, but it is perfectly possible to design a converse structure in which the male pins protrude from the corresponding insert and the female pins are fully incorporated into their own insert.

Naturally, the male pins could be housed in an “outer” sleeve and the female pins could be housed in an “inner” sleeve.

The connector shown inFIG. 1is of the two-channel type, that is to say that it is suitable for simultaneously connecting two two-wire transmission lines. Naturally, the connector according to the invention may be designed for a single channel; it then comprises only one sleeve housing one insert and one pair of pins.

Conversely, one and the same connector may comprise a larger number of sleeves, for the simultaneous coupling of a corresponding number of lines. Each sleeve forming part of the same metal casing23then houses one insert26band two pins25b. In the example ofFIG. 4, the sleeves are arranged side by side and in a single row.

Outer sleeves30bform only one elongated block. Corresponding inner sleeves, on the other connector not shown, are separate.

This connector provides for the simultaneous connection of four two-wire transmission lines. In the embodiment ofFIG. 5, the sleeves are placed side by side and on (at least) two parallel rows. In the example more specifically described with four channels, the sleeves are therefore placed “in a square”.