Enhanced jack with plug engaging printed circuit board

An electrical connector includes a housing, a printed circuit board (PCB), and a plurality of contacts. The housing includes a mating end and a wire receiving end. The PCB is mounted within the housing and has an opening formed therethrough. The plurality of contacts is configured to extend from the PCB. The opening is configured to receive a second electrical connector configured to mate with the electrical connector.

BACKGROUND OF THE INVENTION

The invention relates generally to electrical connectors, and more particularly, to a connector that minimizes crosstalk among signal conductors in the connector.

In electrical systems, there is increasing concern for preserving signal integrity as signal speed and bandwidth increase. One source of signal degradation is crosstalk between multiple signal paths. In the case of an electrical connector carrying multiple signals, crosstalk occurs when signals conducted over a first signal path are partly transferred by inductive or capacitive coupling into a second signal path. This is sometimes referred to as negative coupling. The transferred signals produce crosstalk in the second path that degrades the signal routed over the second path.

For example, a typical industry standard type RJ-45 communication connector includes contacts that are planar in the mating region and physically long. The RJ-45 plug design is dictated by industry standards and is inherently susceptible to crosstalk. In conventional RJ-45 plug and jack connectors, all conductors extend closely parallel to one another over a length of the connector body. One pair of conductors is also split around another conductor pair. Thus, signal crosstalk may be induced between and among different pairs of connector conductors. The amplitude of the crosstalk, or the degree of signal degradation, generally increases as the frequency increases. More crosstalk can be created by the contacts in the jack that interface with the contacts in the plug. As signal speed and density increase, alien crosstalk (e.g., crosstalk between neighboring contacts and/or conductors) must also be addressed in preserving signal integrity at both the current Category 6 transmission frequency standard of up to 250 MHz, and at future (higher) transmission frequency standards.

At least some RJ-45 jacks include features separate from the signal contacts that are intended to suppress or compensate for crosstalk inherent to signals within a mating plug. However, the shortcomings that are inherent in jacks such as the RJ-45 can be expected to become more problematic as system demands (e.g., transmission frequencies) continue to increase. A connector that minimizes crosstalk as close as possible to the mating point of the plug contacts and jack contacts is needed rather than another connector that corrects for crosstalk after the signals have passed through the signal contacts.

Physical stability in the mechanical connection between a plug and jack can also be improved. In current configurations, the plug fits almost entirely within the jack. Contacts within one or more of the plug and jack are biased towards one another in an attempt to maintain good electrical contact between the respective plug and jack contacts. However, the housings for the jack and plug are typically configured for easy insertion and removal from one another, rather than for providing stability to the connection therebetween. Housings that improve the stability of the mechanical interconnection between a plug and jack are also needed.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, an electrical connector is provided. The electrical connector comprises a housing comprising a mating end and a wire receiving end, and a printed circuit board (PCB) mounted within the housing, the PCB comprising an opening formed therethrough. The electrical connector further comprises a plurality of contacts configured to extend from the PCB. The opening is configured to receive a second electrical connector configured to mate with the electrical connector.

In another aspect, a printed circuit board (PCB) configured for placement within a housing of an electrical connector is provided. The PCB comprises an opening formed therethrough and dimensioned for insertion of a portion of a second electrical connector, a plurality of contacts attached to the PCB and configured to extend into the opening, a plurality of circuit traces formed therein, and a plurality of wire receiving holes formed therein. The circuit traces extend from a respective contact to a respective said wire receiving hole.

In a further aspect, a method for reducing crosstalk between contacts in an electrical connector for signals above 250 MHz is provided. The method comprises providing a printed circuit board (PCB), having an opening therethrough, the opening dimensioned to accept insertion of at least a portion of a mating electrical connector, and configuring the PCB with a plurality of contacts that extend into the opening, each said contact configured to make non-linear physical contact with respective contacts of the mating electrical connector.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a perspective view of an electrical connector10formed in accordance with an exemplary embodiment of the present invention. In the embodiment, electrical connector10is configured as a jack12. The jack12may be mounted on a wall or panel, or, alternatively, may be mounted in an electrical device or apparatus having a communications port through which the device may communicate with other external networked devices. In addition, the jack12may be configured as an in-line device, where jack12and plug14(shown inFIG. 2) are utilized to connect two cables. The electrical connector (e.g., jack12) will be described in terms of an assembly having eight discrete contacts20within that are accessible from a mating end22to provide contact with wires (not shown) from a wire receiving end24of a housing26of the jack12. In at least one embodiment, the eight discrete contacts are to be configured as four differential pairs. The contacts20are accessed through an opening28in the mating end22of the housing26. A locking mechanism30extends into opening28that is configured to engage a portion of the plug14to retain the plug14within the jack12.

It is to be understood that the benefits described herein are also applicable to other connectors carrying fewer or greater numbers of contacts in alternative embodiments. The following description is therefore provided for illustrative purposes only and is but one potential application of the inventive concepts herein. As further described herein, contacts20are mounted on a printed circuit board (PCB) that is fixed in position with respect to the housing26. The contacts may includes one or more pairs of contacts20configured as differential pairs.

FIG. 2is a perspective view of the plug14that is configured to mate with the jack12. As can be ascertained fromFIG. 2, plug14has a substantially similar cross section as opening28of the jack12as it engages the opening28. The plug14includes a plurality of channels40formed therein with one contact42located in each of the channels40. Each contact42is configured to make electrical contact with one of contacts20when the plug14is inserted into the jack12. The plug14is configured with a connector latch lever44for latching the plug14to the jack12, utilizing the locking mechanism30within the jack12as will be described. The connector latch lever44extends from a connector latch molding46that is formed as part of the body of plug14.

FIG. 3is a mating end view of the jack12. As viewed through opening28, a printed circuit board (PCB)100is substantially vertically mounted, with respect to opening28, within the housing26. An outline of PCB100is illustrated, partially in phantom view, and in one embodiment, housing26is molded to retain PCB100in such a position. The contacts20of jack12are shown as being mounted on PCB100and are further explained below.

FIG. 4is a frontal view of PCB100configured to be installed within the housing26of the jack12. As illustrated, PCB100is configured with a plug opening102therethrough which allows at least a portion of plug14to pass through. The plug opening102also includes a latch molding engaging portion104which is configured to allow at least a portion of the connector latch molding46of plug14to pass through. Insertion of the plug14into the PCB100, along with the engagement of latch molding engaging portion104and connector latch molding46and the engagement of the connector latch lever44with jack12provides improved stability to the physical connection between jack12and plug14as compared to previously known plug and jack configurations, at least in part because the plug14engages both the PCB100, as described herein, and the housing26of the jack12.

The PCB100further includes a plurality of contact receiving holes110configured for the insertion of an electrical conductor, for example, a compliant pin or other solder contact. In one embodiment, contact receiving holes110are plated through and configured for the connection of a compliant pin contact. In one embodiment, the PCB100is a multiple layer circuit board and, though not shown inFIG. 3, the PCB100is configured with a plurality of conductive traces that extend from a respective one of the contacts20, to a respective contact receiving hole110. In an embodiment, these conductive traces are sized and routed in a configuration to reduce or eliminate any crosstalk that might occur between the contacts20as a result of engagement of those contacts20with a respective contact42of plug14. More specifically, the conductive traces may be oriented within the PCB100to limit an amount of crosstalk between signals conducted through the traces.

FIG. 5is a perspective view of PCB100. In the view ofFIG. 5it is shown that there are two contacts20attached to PCB100for each contact42of plug14. However, in alternative embodiments, there may be a single contact20for each contact42. In the embodiment shown inFIG. 5, to distinguish, contacts20are sometimes referred to herein as forward contacts120and rearward contacts130. A single forward contact120and single rearward contact130are sometimes referred to as a contact set. For each contact set, one of the contacts120,130is configured to operate as a signal contact and the other contact120,130of the contact set is configured to operate as a compensation contact. Multiple configurations of signal contacts and compensation contacts are possible. In one embodiment, all forward contacts are configured as signal contacts and in another, all rearward contacts are configured as the signal contacts. In further embodiments, combinations of forward contacts and rearward contacts as signal contacts are contemplated as long as each contact set includes both a signal contact and a compensation contact. Those contacts configured as signal contacts are the contacts from which the above described conductive traces extend, extending to the respective contact receiving hole110as above described.

Some or all of the compensation contacts will electrically connect to one or more compensation elements (not shown) located on PCB100. The compensation elements are selected to provide a desired noise compensation to the respective signal contacts. Additional conductive traces (not shown) may extend from the contacts configured as compensation contacts. These additional conductive traces are configured to provide one or more of a reactance, a ground plane, and shielding to PCB100as further described below in order to improve the integrity of the signals passing to the respective signal contact. These conductive traces are generally referred to herein as compensation elements.

More specifically, the compensation elements are selected to provide a desired crosstalk compensation to counteract crosstalk at the contacts42in the plug14through direct contact of the compensation contacts with the plug contacts42. From the perspective of the jack12, the plug contacts42and the wires (not shown) extending through plug14are considered to be a noise source, or more specifically, a source of crosstalk. Thus, in applying compensation directly to the plug contacts42, the crosstalk compensation is applied to the source of the crosstalk.

In one embodiment, the compensation elements include a conductive element that provides a reactance that is configured to counteract the crosstalk that may be present within the plug14. In an exemplary embodiment, the reactance primarily includes a capacitance. The compensation elements may be formed using techniques well known in the art, for example, capacitive coupling, for such purposes. For example, two or more compensation contacts may be placed in close proximity to each other so as to create the reactance to counteract the crosstalk. Another method may include placing conductors on the PCB100in close proximity to one another, such as interlaced or aligned copper pours. A third method may include placing discrete chips such as a capacitor on the PCB100in contact with the conductive traces. The compensation elements may also include other circuit components that create a coupling to counteract the crosstalk within the plug14.

In alternative embodiments, contacts120and130are attached to PCB100using at least one of a compliant pin process, a solder process and a clip-on process. As described above, contacts120and130are configured to engage (e.g., make electrical contact), with the contacts42of plug14upon its insertion into jack12. However, a shape, location, and orientation of contacts120and contacts130is believed to be different than that of contacts utilized in known jacks, and, as further explained, results in a reduced electrical path length for the signals traveling between contacts42and contacts120and130. In known jack and plug configurations, the contacts are substantially rectangular and elongated, and result in a comparatively long electrical path for the signals through the contacts of the plug and jack before any signal compensation can be applied. In the embodiments described herein, the electrical path length for signals traveling through contacts42and20, from contact to PCB100is greatly reduced at compared to known plug and jack configurations. As such, electrical delays are reduced and the variations in impedance that occur with the longer electrical path lengths in known jack and plug configurations are avoided. In a preferred embodiment, contact between plug contacts42and contact20of the jack occur in the plane of PCB100. As used herein, the phrase “within the plane of the PCB” refers to an area that is bounded by the dimensions of opening102, and the front and back surfaces of the PCB100.

FIG. 6is a side view of forward contact120. Contact120includes a PCB engaging member150that engages the PCB100, for example, by soldering or other attaching methods. As the plug14is inserted into the jack12, the contacts42of plug14engage a plug contact engaging member152of contact120. The engagement causes the plug contact engaging member152to flex downward, as indicated by the arrows. A flexing portion154between the plug contact engaging member152and the PCB engaging member150allows the downward movement of the top portion and further allows the plug contact engaging member152to spring back to an original position when the plug14is removed from the jack12. Together, the PCB engaging member150, the plug contact engaging member152, and the flexing portion154result in a “V” shaped contact with one end of the “V” attached to the PCB100. The configuration of forward contact120is such that area156of the forward contact120, which is within the plane formed by PCB100, makes physical contact with the contact42of plug14. This configuration, as above described, reduces the electrical path length between the mating point of forward contact120and plug contact42and the compensation available within PCB100. Such a configuration reduces the possibilities for crosstalk to occur between adjacent signal contacts, at least as compared to known plug and jack contact configurations.

FIG. 7is a side view of rearward contact130. Contact130includes a PCB engaging member160that engages the PCB100, for example, by soldering or other attaching methods. As the plug14is inserted into the jack12, the contacts42of plug14engage a top portion162of contact130. The engagement causes the plug contact engaging member162to flex downward and bend slightly, as indicated by the arrows. A first flexing portion164between the plug contact engaging member162and the PCB engaging member160allows the downward movement of the plug contact engaging member162and further allows the plug contact engaging member162to spring back to an original position when the plug14is removed from the jack12. The plug contact engaging member162also includes a second flexing member166that allows the above described slight bending. Overall the rearward contact130has an “S” shape as above described which allows the flexure at the first flexing member164and the second flexing member166. The configuration of rearward contact130is such that area168of the plug contact engaging member162of the contact130makes physical contact with the contact42of plug14also within the plane formed by PCB100resulting in the benefits (e.g., reduced crosstalk) of reduced electrical path lengths as described above.

FIG. 8is a side view illustrating contact between the forward contact120and the rearward contact130with contact42of plug14. For reference, a portion of PCB100is shown along with a portion of plug14. As described above, the contact within the plane formed by PCB100(e.g., at area156of contact120and area168of contact130respectively) reduces crosstalk between the multiple contacts120and also between the multiple contacts130as the signals are quickly routed to the PCB100for compensation. Known Category 6 contact interfaces are only required to be operable (e.g., maintain signal integrity) to about 250 MHz. However, by utilization of jack12and14and the contacts120and130therein, the contact engagement within the plane of PCB100, resulting in the described reduction in electrical path length for the signals, is operable at frequencies above 250 MHz. (e.g, 500 MHz and beyond). In addition, some contact configurations in known jack and plug configurations, specifically RJ-45 jack and plug configurations are in excess of ½ inch and up to 1 inch in length before any compensation is encountered which adds to the problems associated with crosstalk. Utilization of PCB100and contacts120and130, in one embodiment, reduce the length between the contact mating area and the compensation available within PCB100to about 0.25 inch to about 0.35 inch. This reduction in electrical path length results in a reduced time delay and reduction in impedance variations before compensation techniques are applied to the signals to and from plug14. PCB100may also include circuitry and shielding that can affect electromagnetic performance of the signals passing through as plug14is configured to at least partially pass through the PCB100.

Such a configuration also allows an overall length of jack12to be reduced from known jack and plug embodiments. Utilization of PCB100also provides a physically stronger and more stable interconnection between jack12and plug14than is accomplished in previous configurations, in part because the plug14engages both the PCB100and the housing26of the jack12. In one embodiment, housing26is formed, typically molded with a PCB carrier therein. The PCB carrier is typically a channel formed around an interior perimeter of housing26to retain PCB100. In a typical embodiment, housing26is formed in two pieces which allows for the easy insertion of PCB100into housing26.