COMMUNICATION CONNECTORS UTILIZING MULTIPLE CONTACT POINTS
1. A communications jack, comprising:
- a jack housing; and
a sled assembly positioned at least partially in the jack housing, the sled assembly comprising;
a printed circuit board (PCB), wherein the PCB is a rigid-flex PCB having a front rigid section, a rear rigid section, and a flexible section connecting the front rigid section to the rear rigid section; and
a plurality of plug interface contacts (PICs) secured within a front section of the PCB, the plurality of PICs comprising first, second, third, and fourth different rows of PICs.
Disclosed herein are various communications systems allowing for multiple contacts points between plug contacts in a communications plug and plug interface contacts (PICs) in a communications jack. In some disclosed implementations, a communications plug including a first and a second plug contact mated with a communications jack having a first and a second plug PIC may form a plurality of plug/jack interfaces. The plug/jack interfaces may form multiple current paths between the communications plug and the communications jack. When a signal propagates between the communications plug and the communications jack, it may be split in the communications plug between a first current path and a second current path, and recombined in the communications jack after traveling through the plurality of plug/jack interfaces.
- 1. A communications jack, comprising:
a jack housing; and a sled assembly positioned at least partially in the jack housing, the sled assembly comprising; a printed circuit board (PCB), wherein the PCB is a rigid-flex PCB having a front rigid section, a rear rigid section, and a flexible section connecting the front rigid section to the rear rigid section; and a plurality of plug interface contacts (PICs) secured within a front section of the PCB, the plurality of PICs comprising first, second, third, and fourth different rows of PICs.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
This application is a continuation of U.S. application Ser. No. 15/904,620, filed on Feb. 26, 2018 (now allowed), which claims the benefit of priority to U.S. Provisional Patent Application No. 62/465,984, filed on Mar. 2, 2017, both of which are hereby incorporated by reference in their entireties.
Network communications have come to rely heavily on twisted pair cables, and RJ45 plug and jacks which enable connectivity. RJ45 plug and jacks are designed to mate together by way of plug contacts within the plug and plug interface contacts (PICs) within the jack. When plug contacts of an RJ45 plug contact the PICs of an RJ45 jack, data can flow through the mated plug/jack combination.
The following detailed description references the drawings, wherein:
In accordance with various standards, RJ45 plugs and jacks in use today must meet certain electrical characteristics. These include the requirements for the plug to produce a predetermined amount of crosstalk and for the jack to cancel that predetermined amount of crosstalk. While the production and cancellation of crosstalk can be relatively straightforward at lower operating frequencies, as the frequencies increase, the required crosstalk cancellation (i.e., compensation) becomes more difficult. This difficulty generally stems from the physical distance between the point where crosstalk is generated and the point where crosstalk is cancelled.
Various designs have been proposed to address this issue by describing techniques to minimize the delay between the capacitive compensation in the jack and the crosstalk generation in the plug. In these cases, inductive compensation must be implemented in the jack to ensure compliance with the far-end crosstalk (FEXT) requirements of a mated connector. While the inductive compensation is required to ensure mated FEXT compliance, it also contributes to the mated near-end crosstalk (NEXT) performance. The distance between the crosstalk generation in the plug and the inductive compensation in the jack is detrimental to the mated NEXT performance as the frequency of operation is increased.
The present disclosure describes various communications systems that allow for multiple contacts points between the plug contacts in the plug and the PICs in the jack, and that allow for mating with these multiple contact points within plug contacts surface for both conventional plugs and a non-conventional plug. In some disclosed implementations, a communications system may include an RJ45 jack with at least some transmission paths having two separate plug interface contacts that allow for multiple contact points between the plug contacts in the plug and the PICs in the jack, which allows for mating with these multiple contacts points within plug contacts surface for both conventional plugs and non-conventional plugs. The communications system may also include a non-conventional plug in which at least some transmission paths having two separate plug contacts allowing for mating to the multiple plug interface contacts within the jack. Splitting the plug contacts into two separate entities compared to a standard/conventional RJ45 plug allows for a controlled delay between the two potential interface contacts between the plug and jack. The communications system may also include multiple signal paths through the plug jack mating region, which allows for more optimal positioning of capacitive and inductive compensation within the jack.
Reference will now be made to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar parts. It is to be expressly understood, however, that the drawings are for illustration and description purposes only. While several examples are described in this document, modifications, adaptations, and other implementations are possible. Accordingly, the following detailed description does not limit the disclosed examples. Instead, the proper scope of the disclosed examples may be defined by the appended claims.
During assembly of sled assembly 66, the first task is to secure the back sled holder 80 to rigid-flex PCB 84. Back sled holder 80 includes an alignment post 106, which aligns with an alignment hole 108 on front rigid section 100. Comb ribs 110 on back sled holder 80 act to keep rear odd PICs 72 and rear even PICs 74 in respective slots. PIC mandrels 112 on back sled holder 80 act to control the bend radius of rear odd PICs 72 and rear even PICs 74. Unlike typical mandrels for controlling bend radius control of PICs, PIC mandrels 112 extend within the RJ45 plug combs during the assembled state. Rear odd PICs 72 are secured to front rigid section 100 at a row of vias 115 and rear even PICs 74 are secured to front rigid section 100 at a row of vias 119 through the means of a soldered connection but other non-limiting means including a press fit connection may be used. Then to keep respective rear odd PICs 72 and rear even PICs 74 aligned rear PIC comb 82 is attached to back sled holder 80, which has alignment combs 114. This connection is made via snaps 116 on PIC comb 82 which align with pockets 118 on back sled holder 80.
The next step is to slide middle sled holder 78 over front rigid section 100 and connect middle sled holder 78 to back sled holder 80. Back sled holder 80 has latches 120 which align with receptive latch pockets 122 of middle sled holder 78. Comb ribs 126 on middle sled holder 78 act to keep front odd PICs 68 and front even PICs 70 in respective slots. PIC mandrels 128 on middle sled holder 78 act to control the bend radius of front odd PICs 68 and front even PICs 70. Unlike typical mandrels for controlling bend radius control of PICS, PIC mandrels 128 extends within the RJ45 plug combs during the assembled state. Front odd PICs 68 are secured to front rigid section 100 at vias 113 and front even PICs 70 are secured to front rigid section 100 at vias 117 through the means of a soldered connection but other non-limiting means including a press fit connection may be used. Rows of vias 113, 115, 117, and 119 may all be different rows on front rigid section 100.
Both middle sled holder 78 and rear sled holder 80 have respective flex support mandrels 132 and 134 that control the bend radius of middle flex section 102 as it transitions from front rigid section 100. Both front odd PICs 68 and front even PICs 70 have a respective secondary bend 135 and 137 that helps reduce the chance of front odd PICs 68 and front even PICs 70 snagging when the plug is withdrawn.
The next step is to slide front sled holder 76 over front rigid section 100 and connect front sled holder 76 to middle sled holder 78. Front sled holder 76 has latches 136 which align with receptive latch pockets 138 of middle sled holder 78, Front sled holder 76 has PCB pocket 142, which aligns with PCB notch 144 on front rigid section 100, which serves dual purposes of providing more PCB routing space and added alignment.
Rear sled holder 80 includes guide rails 146 which align with respective guide slots 148 of jack housing 64. Middle sled holder 78 includes guide rails 150 which align with respective guide slots 152 of jack housing 64.
Rear sled holder 80 includes spring post 154 for alignment of spring 87 during final assembly. PCB support 86 includes spring hole 156, which provides clearance for spring 87. Rear rigid section 104 also include a PCB spring hole 157 for clearance of spring 87. PCB support 86 includes a placement post 158 which aligns with placement hole 160 of rear rigid section 104. Bend radius control mandrel 162 of rear sled holder 80, controls the bend radius of middle flex section 102 as it transitions into rear rigid section 104. In order to back up PCB support 86 during termination of cable 58 to IDCs 88, multiple support features have been added. These support features include top support bar 164, middle support arms 166, and bottom support arms 168.
IDCs 88 are terminated to vias 170 of rear rigid section 104 though a compliant pin termination but other non-limiting means of termination may be used such as soldering. Clearance holes 172 on PCB support 86 act as clearance for IDCs 88. Clearance slits 174 of rear sled 90 act as clearance for IDCs 88. Positioning posts 176 of rear sled 90 align with positioning cutouts 178 of rear rigid section 104. Rear sled 90 includes spring post 180 for alignment of spring 87 during final assembly. Rear sled 90 includes flex spacer 182, which controls the spacing between middle flex section 102 and conductive shield 62. This controlled spacing is preferred for better impedance control within the middle flex section 102, as if there was inconsistent spacing between middle flex section 102 and conductive shield 62, electrical results would be more unpredictable. Rear sled 90 includes housing snaps 184 which align with snap pockets 186 of jack housing 64.
Rear sled 90 includes alignment slots 188, which align with grounding ribs 190 of conductive wire cap back 96. Alignment slots 188 help to ensure that when inserting wire cap assembly 92 into rear sled 90, proper alignment occurs before IDCs 88 engage with the conductors of cable 58. Grounding pockets 192 of rear sled 90 provide clearance for grounding flanges 194 of conductive shield 62, which during final assembly make an electromechanical connection with grounding ribs 190. Grounding flanges 195 of conductive shield 62 also makes an electromechanical connection with conductive wire cap back 96 but is not constrained by rear sled 90. Plug grounding flanges 196 and 197 make contact with the shield/conductive body of respective shielded RJ45 plug assemblies and provide an electrical bond. Reliably bonding all of the metal non-signal carrying components mitigates EMI susceptibility and enables shielding effectiveness that will meet the standards'"'"' requirements.
In conventional RJ45 shielded solutions there are only two contact regions between the external shield of the plug and that of the jack, as this is all that is defined in IEC 60603-7-1:2011 and IEC 60603-7-7:2010. This contact region is on the side of the plug and jack comparable to the contact of plug grounding flanges 196. However, as the operating frequency of the jack increases, complying with the shielding effectiveness requirements becomes more challenging. This is due to the fact that as the frequency of the signal increases, the impedance through any one shielding interface increases due to the inductance through the shielding contact. To ensure a low impedance shield connection through the connectivity, multiple contact locations between the plug and jack shield can be added to lower the overall inductance. In addition, higher frequency signals will pass through smaller and smaller openings, which in turn has a negative effect on the EMC performance of a cabling system. The addition of plug grounding flanges 197 creates a more comprehensive grounding connection around the port opening. In order to further reduce the opening size of conductive shield 62, shield icon slot 198 and shield front latching slot 200 were both reduced so that the outer interface is covered by conductive shield 62.
IDCs 88 of shielded RJ45 network jack 54 are arranged in a balanced manner to maintain acceptably low levels of internal pair-to-pair coupling. Additionally, IDCs 88 are spaced within each pair to maintain a predetermined impedance so as to not detrimentally affect return loss at the wire cap termination interface.
During the assembly operation of shielded RJ45 plug assembly 56 the first step places rear conductive shell 226 and bend radius control boot 228 over shielded cable 60. During the assembly process front combs 203 attaches to conductive shell 204 through latches 230, which aligns with pockets 236. During the assembly process front housing 202 attaches to conductive shell 204 through latches 234, which aligns with pockets 238.
Once PCB assembly 206 is installed, latches 234 are trapped from backing out of pocket 238. Relief slot 238 in conductive shell 204 acts as both clearance and an added tangle prevention feature for plug latch 240.
During the assembly process of PCB assembly 206, plug contacts 208-214 are placed into vias 242, 244, and 246. Vias 242, 244, and 246 are positioned in different rows on PCB 216. Plug contacts 208 and 210 attach to PCB 216 in a first row of vias 242, plug contacts 214 attach to PCB 216 in a second row of vias 244, and plug contacts 214 attach to PCB 216 in a third row of vias 246. Plug contacts 208 may be generally T-shaped, plug contacts 210 may be generally C-shaped, and plug contacts 212 and 214 may be generally upside-down U-shaped.
Plug contacts 208-214 are shown with compliant pin connections but other non-limiting means such as soldering may be used for electrical and mechanical interfacing with PCB 216. Unlike many vias in electrical connectors, vias 242-246 are routed such that at least some are not circular, instead they are oval. This is to increase the spacing between adjacent vias, while still allowing for a reliable compliant pin design. IPCs 218 are placed into IPC vias 248 and un-plated holes 250. Shielded divider 220 slides into PCB slot 252; shielded divider 220 is secured in the assembly when front load bar 222 and rear load bar 224 are installed.
Electrical isolation of IPCs 218 is achieved through three means. The first mean is from foil over the pairs in cable 60. This foil isolates coupling from the front row of conductors to the bottom, through PCB 216 as conductor pairs are no longer in foil when in rear load bar 224. The second means is through isolation with shielded divider 220, which mitigates coupling of adjacent pairs, specifically when no longer in foil. The third means of isolation is front to back separation of the front load bar 222 and rear load bar 224 such that no conductor pair that is not in foil runs on top of each other over PCB 216. In order to insulate the foil from IPCs 218 and PCB 216, a polyimide film may be placed over the board or the exposed areas of foil may be covered with a non-conductive material such as, but not limited to, heat shrink or tape.
The alignment of rear conductive shell 226 and conductive shell 204 is ensured by the alignment of posts 254 of conductive shell 204 and alignment slots 256 of rear conductive shell 226. The length of alignment posts 254 helps strengthen and secure the crimp tooling. Engagement rib 258 on rear conductive shell 226 acts to secure bend radius control boot 228. Embosses 260 of rear conductive shell 226 align clearance slots 262 which prevent rotation of bend radius control boot 228 during final assembly.
Plug contacts 210 are associated with conductor 3, 4, 5, and 6, however instead of mating with multiple PICs, each plug contact 210 only mates with one PIC. When mated with shielded RJ45 network jack 54 plug contact 2103 mates with rear odd PIC 723. When mated with shielded RJ45 network jack 54 plug contact 2104 mates with rear even PIC 744. When mated with shielded RJ45 network jack 54 plug contact 2105 mates with rear odd PIC 725. When mated with shielded RJ45 network jack 54 plug contact 2106 mates with rear even PIC 746.
Plug contacts 212 are associated with conductors 3 and 6, and also only mate with one PIC. When mated with shielded RJ45 network jack 54 plug contact 2123 mates with front odd PIC 683. When mated with shielded RJ45 network jack 54 plug contact 2126 mates with front even PIC 706. Plug contacts 214 are associated with conductors 4 and 5, and also only mate with one PIC. When mated with shielded RJ45 network jack 54 plug contact 2144 mates with front even PIC 704. When mated with shielded RJ45 network jack 54 plug contact 2145 mates with front odd PIC 685.
The IEC-60603-7:2010 preferred electrical mating point location is typically considered roughly on the front radius of the plug contact. When shielded RJ45 plug assembly 56 is mated with shielded RJ45 network jack 54 both rear odd PICs 72 and rear even PICs 74 mate in what would be defined as the IEC-60603-7:2010 preferred electrical mating point location. When shielded RJ45 plug assembly 56 is mated with shielded RJ45 network jack 54 both front odd PICs 68 and front even PICs 70 mate on the flat of a plug surface which is out of the defined IEC-60603.7:2010 preferred electrical mating point location, but still can be used for mating.
To prevent snagging of either front odd PICs 68 or front even PICs 70 upon retraction of shielded RJ45 plug assembly 56 from shielded RJ45 network jack 54, the plug contact mating surface needs either be roughly flat or slope up into the plug combs so that upon withdrawing shielded RJ45 plug assembly 56 there is no catch point. Also, the plug contact mating surface needs to be relatively continuous. As on at least some of the conductors there are multiple plug contacts, this surface is no longer continuous. Leveling rib 263 of front combs 203 acts as a surface to keep the gap between two plug contacts relatively continuous, specifically this is done between plug contacts 210 and plug contacts 212 as well as between plug contacts 210 and plug contacts 214. Upon withdrawal of shielded RJ45 plug assembly 56 from shielded RJ45 network jack 54, front odd PICs 68 or front even PICs 70 would temporarily make contact with leveling ribs 263 of front combs 203.
The NEXT requirement between pairs 3-6 and 4-5 of a mated connector is the most difficult to satisfy. This is because the inherent crosstalk between pairs 3-6 and 4-5 in an RJ45 plug is the highest of all possible pair combinations. A traditional RJ45 plug and jack will have eight plug contacts arranged to mate with eight PICs in the jack at the plug/jack interface. The crosstalk compensation elements in a traditional RJ45 jack are positioned as close as possible to the plug/jack interface to minimize the distance between the crosstalk generation in the plug and the crosstalk compensation in the jack. For NEXT compensation between pairs 3-6 and 4-5, this is especially critical.
The ideal implementation of NEXT compensation in a traditional mated RJ45 connector will position the capacitive compensation directly at the plug/jack interface, for example through a stub connection. Inductive compensation is then positioned along the current paths within the jack either along the PICs or along the traces on a jack printed circuit board.
Similarly, the delay between the crosstalk in the plug and the inductive compensation in the jack can also be reduced or possibly eliminated. The current flow through a traditional mated connector propagates from the cable, through the plug and plug contacts, across the plug/jack interface, through the PICs, and along the transmission paths in the jack to the jack IACs. By connecting the additional PICs 683, 704, 685, and 706 to the traditional PICs 723, 744, 725, and 746 through jack rigid-flex PCB 84 for the 3-6 and 4-5 pairs, a second current path 280 (
Traditional current path 282 continues from differential transmission paths 288 and 290 through plug PCB 216 toward the nose of the plug and the traditional plug/jack interface 278. Along this path, inductive and capacitive crosstalk is introduced to produce the appropriate amount of NEXT and FEXT between pairs 3-6 and 4-5 in the plug. A portion of this crosstalk can be seen in
The second current path 280 branches off from differential transmission paths 288 and 290 at location 292 through additional plug contacts 2123, 2144, 2145, and 2126 towards the second plug/jack interface 276. Additional plug contacts 2123, 2144, 2145, and 2126 along with the coupling between the contacts are shown schematically in
Power over Ethernet (PoE) allows a single cable to provide both electrical power and data connections, which eliminates the need for additional power cables and devices such as transformers and AC outlets. Some non-limiting examples of PoE devices include Voice over IP (VoIP) phones, wireless access points, network routers, switches, industrial devices (controllers, meters, sensors), nurse call stations, IP security cameras, televisions, LED lighting fixtures, remote point of sale kiosks, and physical security devices. PoE was launched into the market in 2003, standardized under IEEE 802.3af, and allowed for a power draw of 12.95 W and 350 mA per pair (Type 1). POE+ was launched into the market in 2009, standardized under IEEE 802.3at, and allowed for a power draw of 25.5 W and 600 mA per pair (Type 2). As the need for more and more power becomes apparent, non-standard applications such as Cisco'"'"'s Universal Power over Ethernet (UPoE) at 60 W and Power over HDBaseT (100 W), with 1000 mA per pair of current capacity, have arisen. As of 2015 there is a proposed IEEE 802.3bt (PoE++) with 49 W (Type 3) to 100 W (Type 4) of power draw and 600 mA (Type 3) to 1000 mA (Type 4) per pair of power, expected to be available in 2016. In the future, there are potential applications that could require a current capacity of 1500 mA per pair or more.
However, with this new increase in power and standardization of PoE, many connectors were not previously mechanically designed for durability under this electrical load. In a PoE application upon disconnection of the plug and jack connector there is an electrical discharge that can damage the plug and jack mating interface. This electrical discharge can be seen as an electrical arc (spark) or a corona discharge. A spark is a fast, single event that is time independent and may cause a large distinct crater on either the plug contacts or the PICs of the jack module, or both. A corona discharge is a relatively slower event that is time dependent, has multiple events, and causes many shallow craters or pits that erode either the plug contacts or the PICs of the jack module, or both. These effects are worsened after multiple insertions as erosion caused by mechanical abrasion also damages the plug/jack mating interface. IEC 60603-7, requires a minimum of 750 plug insertions into a jack module. Many vendors test to a higher amount of insertion cycles as for some applications 750 plug insertions is relatively low. The effects of this damage are seen in the form of physical damage, electrical interface degradation, and over time, corrosion on the contacts. To quantify these effects, IEC developed test methods IEC 60512-9-3 and IEC 60512-99-001 (Arcing Test Method Standards).
Note that cable 58 and 60 are shown as shielded cable but may be any other non-limiting form of cable including, but not limited to, F/UTP or UTP cabling. Also, although shielded RJ45 network jack 54 utilizes multiple PICs per each conductor, variations of this can be done such as just utilizing multiple PICs per each conductor on conductor pairs 3-6 and 4-5.
Note that while the present disclosure includes several embodiments, these embodiments are non-limiting, and there are alterations, permutations, and equivalents, which fall within the scope of this invention. Additionally, the described embodiments should not be interpreted as mutually exclusive, and should instead be understood as potentially combinable if such combinations are permissive. It should also be noted that there are many alternative ways of implementing the embodiments of the present disclosure. It is therefore intended that claims that may follow be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present disclosure.