1. Field of the Invention
The present invention relates to the field of connectors, more specifically to connectors suitable for use in high-speed data communication.
2. Description of Related Art
High-speed connectors are known and while a number of configurations exist, they typically include multiple high-speed data paths that allow two components to communicate together. One version of a high-speed connector is a plug connector and a receptacle connector that mate together. While different version are possible, one plug connectors that is known and has been used in standard connector designs is the SFP plug connector design compatible with the SFF Committee INF-8074i specification for SFP (Small Form factor Pluggable) Transceiver. While the overall shape of the connector has proven satisfactory for a number of uses, changes in technology have created a demand for a connector with improved performance. One method of addressing this demand is to make the connector wider, thus increasing the number of data channels. Unfortunately, the additional width takes up more space and inhibits the ability to make the components (and the resulting products) more compact. Therefore, increasing the effective speed of the data channels becomes more desirable. In general, increasing the data rate requires using either more complex signaling encoding (e.g., going from NRZ to PAM-5 encoding) or using higher frequencies to increase the effective data rate. It has been determined that existing connector designs are not well suited to provide these higher level performance levels, therefore improvements in the connector design would be appreciated.
A connector includes a first and second housing that are configured to be coupled together. The first housing may include a first slot extending along a first edge and the second housing may include a first shoulder configured to be inserted into the first slot. The first slot includes one or more spaced apart ribs that are configured to be deformed upon insertion of the first elongated shoulder into the slot. The connector may include a second edge on one of the first and the second housing with a corresponding shoulder on the other of the first and second housing. The connector may include one or more circuit cards positioned within an internal cavity defined by the first and second housing.
The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which:
a illustrates a partial elevated top view of the connector depicted in
Conductive housings for connectors are known and have been used to shield the internal components of the connectors. As the frequency has increased, the associated wavelengths of interest have decreased. Unfortunately, at high frequencies the wavelengths are so short that even the relatively flat sections of two mating portions of a housing will have sufficient gaps so as to fail to prevent electromagnetic interference (EMI) from entering. Therefore, it has become more problematic to couple two housings together in a manner that provides effective EMI shielding. While the use of a conductive gasket is possible, gaskets increase the piece count of the component, as well as the complexity of assembly. It has been determined that the use of period crush ribs, as will be discussed below, can help improve the EMI shielding in a manner not previously attempted.
Looking first at
The first and second housing 120, 140 cooperate to form a plug portion 160 that includes an opening 161 that leads to a channel 162. As depicted, within the plug portion 160 a first circuit card 240 and a second circuit card 260 are positioned and may be supported by card support 230. A pull latch 180 is mounted to the second housing 140 in a latch groove 142 and is secured in place via a retaining member 200. A wire set 190 is coupled to the first and second housing 120, 140 and the pull latch 180 may be secured to the wire set 190 via a retention band 110. A conductive gasket 220 may be positioned around the plug portion 160 to assist in forming a conductive seal with a corresponding receptacle (not shown).
The wire set 190 may comprise one or more cables with an insulation layer 191 surrounding a shield 192, which in turn surrounds a bundle of conductive elements 194 (typically a number small gauge, insulated wires but shown as a single member for ease of illustration). The first and second housing 120, 140 include a shield support 320 and an insulation support 324 to respectively support and secure the shield 192 and the insulation 191. If desired, the shield support 320, which may comprise two spaced apart curved retaining fingers 122 on the first housing 120 opposing two curved fingers 150 on the second housing 140, can be configured to grip the shield 192 securely. In an embodiment, the curved retaining fingers can be two spaced apart parallel curved members. To avoid excessive compression of the wire set 190, a ferrule 193 maybe inserted under the shield 192 so that when the first and second housing 120, 140 are coupled together, the shield support 320 grips the shield 192 and pinches the shield 192 between the shield support 320 and the ferrule 193. Similarly, gripping portions 130, 152 can be used to retain the insulation layer 191 (although the gripping portions 130, 152 can be configured to provide less compression as the ferrule typically isn't inserted that far into the cable). As can be appreciated, this allows the connector 100 to retain the wire set 190 by gripping the shield(s), which typically is the portion of the cable that is most desirable to and therefore are most suitable for use in retaining the cable in the event a force is exerted on the cable that acts to pull the cable out of the connector.
As depicted, the wire set 190 can comprise three cables, each with a plurality of conductive elements bundled inside if there is desire to split the signal channels (discussed below) into three groups. In an alternative embodiment, some other number of cables, such as 1 or two or four or more cables, may be used if all the data channels are to be directed to differently (e.g., to different receptacles) or if greater flexibility is desired. An advantage of the depicted configuration is that it allows three cables to be coupled in a housing while still allowing the connector to be inserted into a ganged or stacked or ganged and stacked receptacle array. Without such a configuration, the connector size would likely grow and consequentially cause the size of the corresponding receptacle array to also grow.
As can be appreciated from
The retaining member 200 is depicted as being secured to the housing 140 by fasteners 202 that secure wing 208 to the second housing 140. As discussed below, however, other methods of securing the retaining member 200 are contemplated and may provide certain advantages.
As noted above, circuit cards 240, 260 may be supported within the plug portion 160 by the card support 230. In an alternative embodiment (not shown) the first and second housing can include support structure that is integral to the housing. For example, the first and second housing may have retaining features formed in the location where the notches are provided in
The first housing 120 includes a first edge 127 that is configured to mate with a second edge 148 on the second housing 140. To provide superior shielding, the first edge includes an elongated slot 128 configured to mate with an elongated shoulder 146. As pictured, the elongated slot 128 extends a substantial portion of the housing between the plug portion and the opposite end. Furthermore, the elongated slot 128 extends substantially along the entire first edge 127.
The elongated slot and elongated shoulder help seal the first and second housing together. However, as the frequency of signal being transfer over the connector increases, the wavelengths of interest have decreased. Consequentially, it has become difficult to provide a surface that is sufficiently flat so as to electrically seal the first and second housing 120, 140 together for the frequencies of interest. It has been determined if ribs 129 are included at periodic spaces such as space 129a or space 129b in the elongated slot 128, the insertion of the elongated shoulder 146 into the elongated slot 128 will cause the elongated shoulder 146 to engage the ribs 129 and deform them (or crush them). This forced displacement helps ensure that a reliable electrical connection occurs at a predetermined spacing—thus allowing the first and second housing to provide the desired EMI shielding. This also has the advantage of allowing the frequency of ribs (e.g., the spacing between adjacent ribs) to be set so as to control the insertion force required to insert the elongated shoulder 146 into the elongated slot 128. In an embodiment, the spacing between ribs (whether on the same or opposite sides) may be between about 2-3 mm. If a reduced engagement force is desired, the ribs may be spaced between 4-6 mm (although this will naturally allow longer wavelengths to pass through the section between the ribs).
In an embodiment, the ribs 129 may be placed on both sides of the elongated slot 128 in an alternating pattern, as depicted in
In an alternative embodiment, the ribs 129 on the inside or the outside may be omitted so that ribs 129 are only provided on one side of the elongated slot 128 (such as on the outside or the inside of both elongated slots 128). As can be appreciated, including ribs on only one side of the slot can allow for larger ribs and thus allow for more deformation of individual ribs.
It should be noted that in another embodiment, ribs 429 may be placed on the elongated shoulder 446 and inserted into an elongated slot 428 (
The spacing (129a, 129b) between ribs 129 (whether ribs 129 are on one side or on both sides of the elongated slot 128) can be set small enough so that insertion of the shoulder 146 crushes the ribs 129 often enough to create an conductive shield that block spurious signals in the frequency range of interest. In an embodiment, the ribs may have a uniform spacing that is equivalent to a wavelength for a signal at 3/2 the frequency of the Nyquist frequency (which for NRZ signaling is about X/2 GHz for X Gbps performance).
The single wire connector version may be coupled together with clips and crimping steps so as to avoid the use of additional fasteners, as depicted in
Looking again at
In certain configurations it may be desirable to control the orientation of the circuit cards with respect to each other (e.g., it may be desirable to control where each circuit card is positioned). Therefore, positioning elements 232a and 232b can be used. As can be appreciated, if the position elements 232a are spaced apart differently than positioning elements 232b and circuit card 240 and 260 are configured to only be inserted in one of the channels, the orientation of the circuit cards can be controlled. Similarly, positioning elements 332a, 332b and 332c can be arranged so as to ensure a particular circuit card can be positioned in the respective channels 334a, 334b, 334c.
It should be noted that the positioning elements 232a and 232b may be different so as to provide further polarizing functionality. In other words, circuit cards and the corresponding positioning elements may be configured so that a circuit card can be position only in one channel only in particular orientation and location. Furthermore, each circuit card can be configured the same (so that two or more circuit cards can be positioned interchangeably) or each circuit card can be configured differently so that there is only one possible configuration for the positioning two or more circuit cards in the card support. Thus, a high degree of flexibility can be permitted if desired while allowing for careful control of the position and orientation of each circuit card if desired. In addition, a further polarizing feature 231 may be provided on the card support 230 so that it can only be installed in one orientation (and potentially only on one side of the connector). Thus, the desired orientation of the circuit cards can be carefully controlled with respect to each other (e.g., skew can be controlled so the circuit cards are in planes that are substantially parallel) and the orientation of the circuit cards can be readily predetermined.
As can be appreciated from
The present invention has been described in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.
This application claims priority to Provisional Application Ser. No. 61/116,885, filed Nov. 21, 2008, which is incorporated by reference in its entirety herein.
Number | Name | Date | Kind |
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6210178 | DeForest, Jr. | Apr 2001 | B1 |
6549426 | Lawlyes et al. | Apr 2003 | B1 |
6729897 | Lai | May 2004 | B2 |
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Number | Date | Country | |
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20100130063 A1 | May 2010 | US |
Number | Date | Country | |
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61116885 | Nov 2008 | US |