Network interface connector with proximity compensation

DESCRIPTION

Network interface connector with proximity compensation

Background of the invention

Network interface connectors are components of active chain transmission equipment such as routers, switches, controllers, and network interface cards. Only the coupling interface geometry of these connectors is covered by the modular connector standards.

The transmission properties of these connectors usually vary depending on the impedance of the PCB and other components used in the printed wiring boards of active chain transmission equipment. For these reasons the transmission properties, while critical for the functionality of the equipment, are not covered by US or international standards, but are defined by each equipment manufacturer based on their own experimental evaluation.

Network interface connectors require designers to address and solve a combination of unique transmission parameters as well as other limitations common to modular connectors.

These include:

- Low profile

- Variable transmission parameters to be tuned from one application to another

The main transmission parameters are:

Cross Conversation Near the End (NEXT),

Return Loss, and

Common Mode Noise,

- Fully self-contained compensation for, for example, NEXT, loss of return and common mode noise, and

- Multiport or single port, protected or not protected with status indicator LEDs.

Network equipment vendors sell a wide variety of devices for 10/100 MbE, 1GbE and 10GbE. Network interface connectors are integral parts of these devices. The application market requires single port and multiport connectors. The connectors are soldered to multilayer motherboards together with other components such as PHY, resistors, magnetic circuits, capacitors, etc.

In addition, network applications require smaller and denser designs due in part to the fact that the motherboard PCBs are multilayer and expensive.

Conventional techniques to improve the transmission performance of the connectors on a motherboard PCB can be really expensive. A normal RJ45 connector is often the highest component on the PCB - so that its height above the PCB needs to be reduced without sacrificing normal dimensions.

While the contour and dimensions of modular connectors are subject to US and international standards such as the IEC 600603-7 and TIA 568 series, the internal designs of the connectors differ widely.

The desired transmission properties of these connectors usually vary depending on the input impedance of PHY and other components used in the printed wiring boards of active chain transmission equipment.

Typical transmission requirements commonly referred to as categories (category 5e is characterized up to 100 MHz, category 6 up to 250 MHz and category 6a up to 500 MHz) are only used as guides.

The chain transmission companies must have connectors of the same physical dimensions but being able to adapt to any of a variety of options in transmission response. In addition, the electrical response should be differentiated for the various transmission speeds. It is desirable for connectors of identical appearance and footprint, to provide a balanced electrical response for 10/100 Mbe, 1 GbE or 10 GbE microplate assemblies. Currently the connectors are designed for specific topics such as a common mode noise given at a given frequency for a specific PHY.

The performance of a connector is judged either by direct measurement of the transmitted signals or by controlling the main transmission parameters such as NEXT, loss of return and common mode noise and conversion from Common to Differential mode. These parameters are specified in the US in TIA 568-10 and internationally in the IEC 60603-7 series of standards.

RJ45 low profile connectors are known and are used as network interface connectors. Its interface geometry is still regulated by the TIA 568 and IEC / ISO 60603-7 series of standards. However, the network interface connectors are not parts of the channel defined by the standards.

As the situation of the PHY and / or other components in the channel, such as magnetic circuits (filters and isolation transformers) and discharge capacitors, deform the NEXT and Return Loss, the requirements for the compensation of NEXT and RL differ from application in application. In order to meet these requirements, connector manufacturers supply different connectors to work with specific PHYs.

The transmission performance of the RJ45 type network interface connectors is enhanced by internal compensation such as by providing compensation circuits on an internal PCB or on flexible circuits. The connector contacts are soldered to the internal PCBs. Document US2004 / 023563 A1 discloses a network interface connector according to the preamble of claim 1.

It is currently not feasible to improve or modify the transmission characteristics of such connectors after being welded to the motherboard.

Connector tests are performed using the exact network equipment and the application-specific PHY. In order to adjust the performance to a given application, the welding of the connectors must be eliminated and removed from the motherboards, reassembled or discarded and use new connectors. If a problem is found in the field, often the complete network installation has to be replaced or discarded.

It would be advantageous to be able to modify, update or change the transmission characteristics and performance of a network interface connector after it has been soldered to a motherboard.

Compendium of the invention

Accordingly, it is an object of the present invention to provide a new and improved network interface connector, whose electrical properties and transmission characteristics can be easily modified, updated or changed.

Another object of the invention is to provide such a new and improved network interface connector, whose electrical properties and transmission characteristics can be easily modified, updated or changed after it has been soldered to a motherboard.

A further object of the present invention is to provide such a new and improved network interface connector of the modular type whose coupling interface geometry conforms to the standards of the modular connectors.

A further object of the present invention is to provide such a new and improved network interface connector that has a single port or several ports.

A further object of the present invention is to provide such a new and improved network interface modular connector for applications for at least 1GbE.

A further object of the present invention is to provide such a new and improved network interface modular connector that has a low profile and that can be mounted on the middle board.

A further object of the present invention is to provide such a new and improved network interface modular connector whose components are easy to manufacture at a low cost using conventional methods and equipment.

A further object of the present invention is to provide such a new and improved network interface connector whose transmission improvements, such as compensation, are located within the connector.

A further object of the present invention is to provide such a new and improved network interface connector that meets the specified requirements selected when tested as specified in TIA 568A and IEC 60603-7.

A further object of the present invention is to provide such a new and improved network interface connector that can be customized to a high degree to differentiate from 1GbE to other limits specified by customers. A further object of the present invention is to provide such a new and improved network interface connector that can be protected or unprotected and can be provided with status indicating LEDs.

Briefly, these and other objects are obtained by providing a network interface connector according to the claim 1 comprising an outer housing and a set of contacts located in the outer housing. The contact set includes a mounting block, a first group of first elongated or upper contacts mounted in the mounting block and a second group of second elongated or lower contacts mounted in the mounting block. The first and second elongated contacts are configured so that the contact portions of the first and second contacts are coplanar and separated in accordance with US and international standards for modular connectors. The first and second elongated contacts have rear portions that are located in parallel planes separated first and second respectively to define a space of proximity between them. A proximity insert is removably located in the proximity space between the rear portions of the first and second elongated contacts. The proximity insert preferably extends between the rear portions of all first and second contacts.

The proximity insert arrangement is chosen in view of the desired transmission and the properties of the connector. For example, the proximity insert may consist of a printed circuit board that has conductors coupled to the elongated contacts. The proximity insert may be formed of a non-conductive material or a material that has a high dielectric constant such as BaTiO2 or a ceramic material. Alternatively, the proximity insert may be formed by a metallic material coated with an insulating material such as polyimide, PBT or an acrylic paint, or be formed by ferrite.

The contact portions of the first and second contacts preferably alternate with each other. The first and second groups of elongated contacts preferably include four first elongated contacts and four second elongated contacts. At least a couple of first and second elongated contacts cross each other. The connector has a single port or several ports. In a multi-port embodiment, a set of contacts is associated with each port. The contact sets are configured so that the proximity spaces of the contact sets are aligned with each other and the single proximity insert is configured to be located, preferably removably, in aligned proximity spaces.

Detailed description of the drawings

A more complete appreciation of the present invention and many of the concurrent advantages thereof will be quickly understood by reference to the accompanying drawings, which illustrate the preferred embodiments of the invention, wherein:

Figure 1A is an exploded perspective view showing the components of a set of contacts, that is the upper and lower contact arrays, a mounting block, a proximity insert and optional LEDs, of a preferred embodiment of a network interface connector according to the present invention;

Figure 1B is an exploded perspective view showing the set of contacts, the outer housing and the protection of a network interface connector according to the invention:

Figure 2 is a perspective view showing the operating positions of the elongated contacts of the upper and lower contact arrays of the contact assembly of Figure 1 (mounted on an accessory for illustrative purposes);

Figure 3 is a view similar to that of Figure 2 showing a proximity insert of the contact assembly located in a defined proximity space between the rear portions of the contacts of the upper and lower contact matrices respectively;

Figure 4 is a perspective view showing the components of the contact set shown in Figure 1 which includes a mounting block, the contacts of the lower contact array mounted on the mounting block and two proximity inserts that are alternately positioned for mounting in the mounting block on the rear portions of the contacts of the lower contact array;

Figure 5 is a perspective view showing the components of the contact set shown in Figure 1 that include a mounting block, the contacts of the lower contact array being mounted on the mounting block and a proximity insert mounted on the rear portions of the contacts of the lower contact array;

Figure 6 is a perspective view similar to that of Figure 5 showing the contacts of the upper contact array positioned to be mounted on the mounting block;

Figure 7 is a perspective view of the assembled contact assembly shown in Figure 1 showing the contacts of the upper contact array mounted on the mounting block, the rear portions of the contacts of the upper contact array being located on the proximity insert;

Figure 8 is a side section view of a modular network interface connector in accordance with the present invention;

Figure 9 is a perspective view showing a group of various embodiments of proximity inserts according to the present invention;

Figure 10 is a perspective view similar to that of Figure 6 showing a proximity insert comprising a printed circuit board;

Figures 11 (a) - (e) are plan views showing the proximity insert of Figure 10 and the various layers constituting the printed circuit board;

Figure 12 is a perspective view of a set of contacts of a preferred embodiment of a multiport network interface connector according to the present invention;

Figure 13 is a sectional perspective view of a multiport network interface connector according to the present invention;

Figure 14 is a perspective view of the multiport network interface connector shown in Figure 13 and showing a slot for receiving a proximity insert;

Figure 15 is a perspective view of the multiport network interface connector shown in Figures 13 and 14 and showing a proximity insert being received in the slot shown in Figure 14;

Figure 16 is a perspective view showing a group of various embodiments of proximity inserts for use in a multiport network interface connector according to the present invention;

Figure 17 is a perspective view of elongated contacts of a lower contact array showing a capacitive adjustment device; Y

Figures 18 (a) and (b) are graphs that plot electrical responses from the same connector incorporating different proximity inserts.

Description of preferred embodiments

Referring now to the drawings in which the same reference characters designate identical or corresponding parts along the various views and, more particularly to Figures 1a and 1b, the components of a modular network interface connector, generally designated 10 (shown coupled in Figure 9), are illustrated in exploded views. The components include an outer housing 1 and a set of contacts, generally designated 8. The contact set 8 includes an upper or first contact array 3 comprising four first elongated contacts 302, 304, 306 and 308 (Figure 2), a lower or second contact array 4 comprising four second elongated contacts 401, 403, 405 and 407 (Figure 2), a mounting block 5 on which the first and second contacts of the upper and lower contact matrices 3 and 4 are mounted and a proximity insert 6 located between the rear portions of the first and second contacts. According to the invention, a variety of different proximity inserts is possible for use in particular applications to achieve the desired electrical properties and improved transmission characteristics. As described below, the contact assembly 8 is mounted and located inside the outer housing 1. A metal shield 2 is optionally arranged around the housing 1 for use in a protected system as is conventional. A pair of status indicator LEDs 7a and 7b and cables are optionally arranged.

With reference to Figure 2, the configuration of the elongated contacts is illustrated when mounted on the mounting block 5 (not shown in Figure 2). An accessory F is shown for illustrative purposes and does not comprise a part of the connector. The first elongated contacts 302, 304, 306 and 308 of the upper contact matrix 3 each have a front contact portion a and a rear portion b, and the second elongated contacts 401, 403, 405 and 407 of the contact matrix 4 each one has a rear contact portion a and a rear portion c. The first and second elongated contacts are configured so that, when mounted on the mounting block 5 (not shown in Figure 2), the contact portions a of the first and second elongated contacts 401, 302, 403, 304, 405, 306, 407 and 308 are coplanar, the rear portions b of the first elongated contacts 302, 304, 306 and 308 are coplanar, located in the foreground 30 (Figure 3), and the rear portions c of the second elongated contacts 401, 403, 405 and 407 are coplanar, located in a second plane 40 (Figure 3) which is parallel to and separated from the foreground a distance g defining a proximity space 50 (Figure 3). A portion d of the pin extends downwardly from the rear end of each of the rear portions b and c of the first and second contacts of dies 3 and 4. The dimensions and separation of the a portions of the contacts of the first and second contacts are in accordance with US and international standards for modular connectors.

The proximity insert 6 preferably comprises a body that has the shape of a thin rectangular prism that has opposite parallel upper and lower faces 32, 42, although other shapes are possible. He thickness of the proximity insert 6, that is, the distance between the upper and lower surfaces 32 and 42 of the proximity insert 6, is substantially equal to or slightly less than the distance g of the proximity space 50 and is within the range of approximately 0.01 "and 0.2". The proximity insert 6 is located in the proximity space 50 as shown in Figure 3. The rear portions b and c of the first and second elongated contacts of the contact matrices 3 and 4 may be coupled or may be slightly separated from the opposite surfaces 32, 42 of the proximity insert 6 depending on the application.

With reference to Figures 4 and 5, the contact mounting block 5 is formed of an insulating material, for example plastic, and includes a rear frame 12 having a transverse vertical rear wall 14 and a pair of vertical side walls 16 which They extend longitudinally. An upper horizontal shelf 18 extends forward from the frame 12 and a lower horizontal shelf 20 extends forward from the upper shelf 18. Another pair of vertical side walls 22 extend upwardly from the transverse ends of the lower shelf 20. Four longitudinal recesses 24 are formed in the lower shelf 20, which open on the front vertical surface of a vertical transverse wall 26 hanging down from the front end of the lower shelf 20. A horizontal wall 28 extends forward of the lower end of the vertical transverse wall 26. Four transversely separated vertical through holes 34 open on the horizontal shelf 18 and four transversely separated vertical through holes 36 open on the lower horizontal shelf 20. The through holes 34 and 36 are located in alternating longitudinal alignment. Eight longitudinal guide recesses 38 are formed in the area of ​​the front end of the horizontal wall 28. The second elongated contacts 401, 403, 405 and 407 of the lower contact matrix 4 are mounted in the mounting block 5 by inserting their pin portions d through the holes 36 of the lower shelf 20. The rear portions c of the contacts they are received in the respective of the recesses 24 formed in the lower horizontal shelf 20. The contacts have rectangular cross sections and the upper surfaces of the rear portions c are substantially coplanar with, or slightly recessed from, the upper surface of the shelf 20. The contact portions of the second contacts 401, 403, 405 and 407 are they tip down from the front ends of the recesses 24 of the lower horizontal shelf 20 and are coplanar to each other. The front ends of the contact portions 401, 403, 405 and 407 are located in the first, third, fifth and seventh guide recesses 38 (seen from the right side of the contact mounting assembly 5 in Figure 4).

With reference to Figures 4 and 5, a proximity insert 6c, which has an arrangement designed to provide certain electrical characteristics described below, is located on the rear portions c of the elongated contacts 401, 403, 405 and 407 so that its lower surface rests contiguously on the portions c of rear contacts. (Two proximity inserts 6b and 6c are shown in Figure 4 to indicate that a particular proximity insert can be selected from different possible arrangements to provide particular electrical characteristics to achieve the desired transmission properties.) The proximity insert 6c is joined at its sides by the vertical side walls 22 of the mounting block 5. A pair of vertical projections 52 directed backwards and a vertical front wall 54 directed forward extend between the upper and lower horizontal shelves 18 and 20 joining the front and rear surfaces of the proximity insert 6c. As seen in Figure 5, the upper surface of the proximity insert 6c is substantially coplanar with the upper horizontal shelf 18. A notch 5b is formed on the rear surface of the proximity insert 6c closer to one of its sides than the other and a corresponding protrusion 58 extends from the forward facing wall 54 which ensures proper orientation of the proximity insert 6c in the mounting block 5.

The thickness of the proximity insert 6c is substantially equal to the size g of the proximity space 50 (Figure 3) which is substantially equal to the distance between the upper and lower horizontal shelves 18 and 20.

With reference to Figures 6 and 7, the first elongated contacts 302, 304, 306 and 308 of the upper contact array 3 are then mounted on the contact mounting block 5 (in which the second elongated contacts 401, 403 , 405 and 407 and the proximity insert 6c are already mounted) by inserting their pin portions through the holes 34 in the upper shelf 18. The rear portions b of the first elongated contacts rest contiguously on the upper surface of the proximity insert 6c. The contact portions a of the first contacts 302, 304, 306 and 308 are inclined downwardly from the upper horizontal shelf and are coplanar with each other and with the contact portions a of the second contacts 401, 403, 405 and 407. The front ends of the contact portions a of the first contacts 302, 304, 306 and 308 are located in the second, fourth, sixth and eighth guide recesses 38, ie alternating in position with the contact portions a of the second contacts 401, 403, 405 and 407.

As mentioned above, the rear portions b, c of the elongated contacts of the first and second contact matrices 3 and 4 may be coupled or may be slightly separated from the respective opposite surfaces of the proximity insert 6 depending on the application. Proximity insert 6 is not welded to any of the contacts. The set of the first and second contacts of the upper and lower contact matrices 3 and 4 and the proximity insert 6c in the mounting block 5 (as shown in Figure 7) constitutes the contact set 8.

An advantage of the arrangement of the present invention is that the proximity insert is removable from the space of proximity after the connector has been welded to a motherboard and is replaceable by another proximity insert that has different electrical characteristics to provide the connector with different transmission properties without having to remove the solder from the motherboard connector. With reference to Figure 7, in order to facilitate such replacement, the slots 9 (shown only in Figure 7) are formed in the side walls 22 aligned with the ends of the proximity insert 6c. When replacement with a different proximity insert is desired, the new insert is inserted through one of the slots 9 and inserted into the proximity space. At the same time the old insert is pushed out of the opposite slot 9. Appropriate openings are arranged in the outer housing and protection. In this way, the connector can be adjusted for a particular application in the field without the need to eliminate welding or replacement of the network installation.

With reference to Figure 8, the contact assembly 8 is inserted into the outer housing 1 through its open rear side to complete the network interface connector 10. The cables of the LEDs 7a and 7b are located in vertical passages 60 formed in the rear frame 12 of the mounting block and bent forward so that the LEDs are located at the front ends of the respective horizontal passages 62. The metal shield 2 is arranged around the outer housing 1 as is conventional. A single port 64 is arranged and opens on the front of the connector 10 to receive a modular plug connector having contacts located to engage the contact portions of the first and second elongated contacts. The outer housing 1 has a flange 66 formed along the bottom side of the front part of the port 64 to capture the free ends of the contact portions of the elongated contacts.

In Figure 9 five possible proximity inserts 6a-6e are illustrated which can alternatively be interchangeably incorporated as part of a single connector 10 of the port to achieve the desired electrical characteristics according to the invention.

The proximity insert 6a comprises a printed circuit board made of epoxy resin in which metal conductors are embedded. This embodiment is discussed in more detail below in connection with Figures 10 and 11.

The proximity insert 6b is formed of a non-conductive material having a low dielectric constant in a range between about 1.1 to 3.7, such as plastic or paper or PTFE. This type of proximity insert prevents the rear contact portions b and c from engaging each other when the proximity space is small and provides the necessary insulation for high voltages. Due to safety requirements, connectors 10 have to support 1,000 volts between contacts. A proximity insert formed by a high dielectric resistance has a better electrical behavior than air.

The proximity insert 6c is formed of a material that has a relatively high dielectric strength such as BaTiO2 or a ceramic material. The proximity insert 6c increases the coupling and correspondingly increases the differential neighboring crosstalk between the contacts 302 and 401 that can be of opposite phase to the crosstalk in a different part of a complete transmission line, that is to say in the modular connection socket. As a result, total crosstalk will be reduced.

The proximity insert 6d is formed of metal coated on its upper and lower surfaces with an insulating material such as polyimide or PBT or an acrylic paint. Such an arrangement reduces the impedance possibly to the characteristic impedance of the line in the immediate vicinity of the PHY resulting in a better balance and a corresponding better Return Loss.

The proximity insert 6e is formed of a ferrite material in order to comprise a low pass filter that attenuates the unwanted common and differential parasite noise as well as attenuating some of the high frequency portions of the signal spectra, resulting in High fidelity and improvements in signal noise ratios.

Figure 10 illustrates the assembly of the first upper contacts with the mounting block 5 after the assembly of the second lower contacts and a proximity insert 6a of the PCB type in the mounting block 5. The proximity insert 6a contains a pattern capacitive that provides compensation for neighboring crosstalk. The proximity insert 6a is formed by four layers that include an upper layer (Figure 11b), an upper middle layer (Figure 11c), a lower middle layer Figure 11d) and a lower layer (Figure 11e). The PCB connects or is located in close proximity to the rear portions b of the upper contacts 302, 306 and the rear portions c of the lower contacts 403 and 405. Additional conductor patterns of the PCB can be arranged to increase or reduce the characteristic impedance by providing a better conjunction with the dominant impedance of the PHY and thus reduce the reflections and thereby improve the Return Loss. While the illustrated embodiments of the proximity inserts fill the proximity space between the rear portions of all the contacts of the upper and lower dies, the length of the proximity inserts may be shorter and fill the proximity space between only a few of the contacts and also achieve improved transmission properties.

With reference to Figures 12-15, a multiport (four port) embodiment of a network interface connector according to the invention, designated 10 ', is shown. The set 80 of multiport contacts is shown in the Figure 12 and essentially constitutes a single mounting block 5 'of elongated contacts having four sets 8' of separate contacts, each basically identical to the arrangement of the contact set 8 of the single port embodiment. The proximity spaces 50 of the four sets 8 'of contacts are aligned with each other and a single elongated proximity insert 6' extends through the four proximity spaces. As shown in Figure 16, a variety of such elongated proximity inserts, such as inserts 6f-6l, are arranged having the same arrangements as the proximity inserts 6a-6e described above.

The multi-port contact assembly 80 is located in an appropriately formed multi-port outer housing 1 ', which can be covered by a 2' protection as seen in Figure 12.

As seen in Figures 12, 14 and 15, a slot 9 is disposed at opposite ends of the mounting block 5 'and of the outer housing in alignment with the proximity spaces 50. The proximity insert 6f may be located in the proximity spaces 50 inserting it through slot 9. When the proximity insert is inserted through a slot 9 at one end of the housing 1, any previously placed proximity insert will be pushed out of the contact assembly 8 by the new proximity insert through the slot at the other end of the accommodation. Such a procedure can be performed even after the connector 10 'is welded to the motherboard.

With reference to Figure 17, a capacitive extension 11 of the adjustment contact is arranged in a rear portion c of at least one of the lower elongated contacts of the lower contact matrix 4, for example the elongated contact 405. The extension 11 of the Contact is not in the path of the signal and works to allow alternative tuning of the transmission properties of the connector. The extension 11 is stamped using an optional die cutting tool. Several extensions 11 with varying lengths are possible. The extension cannot be seen by the user and does not affect the mechanical appearance or operation of the connector. However, it provides a fine adjustment of the transmission parameters.

Figure 18 is a graphic illustration showing the significant differences in electrical responses, that is in NEXT Front, when the same connector is used with inserts 6a and 6b.

Numerous modifications and variations of the preferred embodiments illustrated are possible in light of the above teachings within the scope of the appended claims.