The subject matter herein relates generally to a transceiver assembly, and more particularly, to a receptacle connector for use in a transceiver assembly.
Various types of fiber optic and copper based transceiver assemblies that permit communication between electronic host equipment and external devices are known. These transceiver assemblies typically include a module assembly that can be pluggably connected to a receptacle in the host equipment to provide flexibility in system configuration. The module assemblies are constructed according to various standards for size and compatibility, one standard being the Small Form-factor Pluggable (SFP) module standard.
The SFP module is plugged into a receptacle assembly that is mounted on a circuit board within the host equipment. The receptacle assembly includes an elongated guide frame, or cage, having a front that is open to an interior space, and an electrical connector disposed at a rear of the cage within the interior space. Both the connector and the guide frame are electrically and mechanically connected to the circuit board, and when an SFP module is plugged into the receptacle assembly, the SFP module is electrically and mechanically connected to the circuit board as well. Conventional SFP modules and receptacle assemblies perform satisfactorily carrying data signals at rates up to 2.5 gigabits per second (Gbps).
Another pluggable module standard, the XFP standard, calls for the transceiver module to carry data signals at rates up to 10 Gpbs. Transmission of data signals at such a high rate compared to SFP modules raises problems not experienced previously in SFP modules. For example, conventional contact configurations of the electrical connector at the rear of the receptacle are inadequate for transmitting the data signals at the desired transmission rates. Electrical parameters such as impedance, crosstalk, skew and jitter are negatively impacted by the conventional design of the electrical connector. While steps have been taken to solve the signal integrity issues caused by 10 Gpbs signals, particularly where there is only one transmit and one receive signal, problems still remain with maintaining signal integrity. For example, there is presently in development by an Industry Group, IEEE P802.3ba “10 Gbps and 100 Gbps Ethernet Task Force”, that transmits and receives multiple 10 Gpbs signals in a parallel configuration. Systems utilizing the parallel configuration have problems maintaining signal integrity. It would be desirable to provide an electrical connector for the receptacle assembly that exhibits good electrical characteristics at high data transmission rates. It would be desirable to provide an interface that exhibits good electrical characteristics in systems that transmit and receive multiple 10 Gpbs signals in a parallel configuration.
In one embodiment, a receptacle connector is provided that includes a housing having a front, a rear, and a cavity configured to receive a mating connector through a slot at the front of the housing. A plurality of contacts are loaded into the cavity of the housing through the rear of thee housing, and the contacts have channel portions aligned with one another. A retention plug is separately provided from the housing and securely coupled to the rear of the housing. The retention plug is received within the channel portions of the contacts and engages the contacts to hold the contacts within the cavity.
In another embodiment, a receptacle connector is provided for mating with a pluggable module of a transceiver assembly. The receptacle connector includes a housing having a front and a rear. The housing includes a cavity configured to receive a mating connector through a slot at the front of the housing. A plurality of contacts are loaded into the cavity of the housing through the rear of the housing. The contacts define signal contacts and ground contacts arranged in a ground-signal-signal-ground arrangement. A retention plug is separately provided from the housing and securely coupled to the rear of the housing. The retention plug has a base and a plurality of fingers extending from the base. The retention plug is coupled to the housing and engages the contacts to hold the contacts within the cavity. The retention plug is arranged such that the fingers are positioned between adjacent signal contacts.
In a further embodiment, a transceiver assembly is provided that includes a receptacle guide frame configured to be mounted to a host circuit board, where the receptacle guide frame has a front being open to an interior space, and where the receptacle guide frame is configured to receive a pluggable module through the front. A receptacle connector is received within the interior space of the receptacle guide frame at a rear of the receptacle guide frame. The receptacle connector includes a housing having a front, a rear, and a cavity configured to receive the pluggable module through a slot at the front of the housing. A plurality of contacts are loaded into the cavity of the housing through the rear of the housing. A retention plug is separately provided form the housing and is securely coupled to the rear of the housing. The retention plug has an elongated base extending along the rear of the housing. The base engages the contacts to hold the contacts within the cavity.
As shown in
In the illustrated embodiment, the pluggable module 102 includes a housing 110 including a base 112 and a cover 114 that are secured together to form a protective shell for a circuit board (not shown in
The pluggable module 102 is configured to be inserted into the receptacle assembly 104. In general, the pluggable module 102 and receptacle assembly 104 may be used in any application requiring an interface between a host system and electrical or optical signals. The pluggable module 102 interfaces to the host system through the receptacle assembly 104 via a receptacle connector 120 which is located within a receptacle guide frame 122, also referred to as a cage. The pluggable module 102 interfaces to an optical fiber or electrical cable (not shown in
The pluggable module 102 and the receptacle assembly 104 reduce EMI emission through one or more of several EMI reduction features, including a guide frame 122, a gasket assembly 125 coupled to a forward end of the guide frame 122 that interfaces with the bezel 108, and intermediate and rear gasket assemblies 123 and 127.
As illustrated in
The receptacle connector 120 is mounted on the circuit board 106 of the host equipment along with the guide frame 122, but separated from the conductive surface 146 of the host board 106. The receptacle connector 120 includes a slot that receives an edge of the circuit board or a connector mounted to the circuit board that is carried by the pluggable module 102 when the pluggable module 102 is fully installed in the guide frame 122, thereby electrically connecting the pluggable module 102 to the host equipment.
The top wall 128 of the guide frame 122 has a large opening 148 overlying the cavity 138 that accommodates an optional heat sink 150. The heat sink 150 is positioned to make physical contact with the pluggable module 102 when the pluggable module 102 is installed into the receptacle assembly 104. A clip 152 is mounted over the heat sink 150 and is secured to the guide frame 122. The clip 152 ensures that the heat sink 150 is loaded against the pluggable module 102 to facilitate thermal transfer from the pluggable module 102 to the heat sink 150. The heat sink 150 includes an engagement surface that faces and is located proximate the interior cavity 138 of the guide frame 122. The engagement surface of the heat sink 150 is configured to physically contact and abut against the pluggable module 102 when installed in the interior cavity 138.
A retention tab 154 is formed on each of the side walls 132, 134 of the guide frame 122. The retention tabs 154 engage the clip 152 which, in turn, retains the heat sink 150 on the guide frame 122. The clip 152 securely engages the guide frame 122 to retain the heat sink 150 upon the guide frame 122. The clip 152 includes resilient spring members 155 secured over the heat sink 150. The spring members 155 flex to permit the heat sink 150 to move outward away from the guide frame 122 when the pluggable module 102 is installed. The spring members 155 exert a desired force against the heat sink 150 to maintain a desired abutting interface to facilitate thermal transfer and heat dissipation from the pluggable module 102. The clip 152 further includes side rails 156 that snap over the side walls 132, 134 of the guide frame 122. The side rails 156 are joined to one another by the spring members 155 that extend over, and flexibly engage, the heat sink 150.
The pluggable module 102 is illustrated in a latched position wherein removal from the guide frame 122 is prevented. An axial pull on the front end 118 of the pluggable module 102 in the direction of arrow A, when latched, is ineffective to remove the pluggable module 102. In the latched position, the front end 118 of the pluggable module 102 extends or protrudes outwardly a specified distance from an EMI gasket collar 178 which is positioned in abutting contact with an interior surface (not shown in
The top wall 128 of the guide frame 122 includes a front portion 186, a rear portion 188, and opposed lateral portions 190, 192 that define a perimeter of the opening 148. The portions 186-192 of the top wall 128 also define a seat for the heat sink 150 (shown in
The rear portion 188 of the top wall 128 includes positive stops 140 in the form of downwardly extending tabs that project slightly inward into opening 148 and downward into the cavity 138. The stops 140 engage a rear surface of the pluggable module 102 to prevent the pluggable module 102 from passing rearwardly through the guide frame 122 beyond a specified distance. Each of the side walls 132, 134 of the guide frame 122 includes a latch element 196 that engages a respective cavity in the sidewalls 132, 134 of the pluggable module 102. In the illustrated embodiment, the latch elements 196 are rectangular tabs punched from the respective side walls 132, 134 and bent inwardly into the interior of the cavity 138 of the guide frame 122. When the pluggable module 102 is inserted in the guide frame 122, the latch elements 196 contact the side outer surfaces of the housing 110 (shown in
The receptacle connector 120 includes a plurality of contacts 320 loaded into the cavity 322 (shown in
The grooves 330 are generally formed by wall portions 332, 334 positioned between the contacts 320. The wall portions 332, 334 of the housing 302 are formed from a dielectric material. Electrical characteristics of the contacts 320 are controlled by selecting a particular type of dielectric material for the wall portions 332, 334 and/or by controlling the height of the wall portions 332, 334 between the contacts 320. Between the wall portions 332, 334, the contacts 320 are separated from one another by air, which has a different dielectric constant than the wall portions 332, 334, and thus affects the electrical characteristics of the contacts 320 differently then the wall portions 332, 334.
Each contact 320 includes a post 340 and a tail 342 (shown in
In an exemplary embodiment, the post 340 includes a rear facing channel portion 346 with an open side aligned with an outer surface 348 of the post 340. The channel portions 346 are aligned with one another. The channel portion 346 is configured to receive the retention plug 324 (shown in
In the illustrated embodiment, the contacts 320 include both signal contacts 356 and ground contacts 358. Other types of contacts, such as power contacts, may be used in alternative embodiments or alternative applications. Optionally, the signal contacts 356 may be arranged in pairs with each signal contact 356 within a pair carrying a differential signal, thus defining a differential pair. One ground contact 358 is provided between each pair of signal contacts 356. Each pair of signal contacts 356 are flanked by ground contacts 358. A ground-signal-signal-ground contact arrangement is thus provided. Other contact arrangements may be provided in alternative embodiments.
In an exemplary embodiment, the ground contacts 358 have a dimension from front to rear between the channel portions 346 and the tails 342 that is greater than the dimension from front to rear of the equivalent section (e.g. the aligned section) of the signal contacts 356. The ground contacts 358 reduce crosstalk between differential pairs by being wider than the signal contacts 356. In an exemplary embodiment, the signal contacts 356 include a forward facing channel portion 360 between the rear facing channel portions 346 and the tails 342. The forward facing channel portions 360 include an inner surface 362 that is spaced apart from the housing 302 to provide an air gap between the signal contacts 356 in the housing 302. Optionally, the ground contacts 358 abut the housing 302 such that no air gap is formed between the ground contact 358 and housing 302.
The housing 302 is open between the channel portions 346 of the contacts 320. In an exemplary embodiment, the housing 302 includes an aperture 364 for receiving a portion of the retention plug 324. Optionally, the retention plug 324 may be securely coupled to the housing 302 by frictionally engaging the walls defining the aperture 364.
In an exemplary embodiment, the base 370 includes a stuffer portion 382 having a reduced height 384 as compared to a height of the base 370. The fingers 372 extend forward from the stuffer portion 382. The stuffer portion 382 is sized to fit within the channel portions 346 (shown in
The fingers 372 extend from the base 370 to a tip 392. The tip 392 may be rounded. The fingers 372 have opposed side surfaces 394, 396. The side surfaces 394, 396 may be smooth. The fingers 372 are spaced apart by the spacing 398. Optionally, the spacing 398 may be the same, or substantially the same, between each adjacent fingers 372. Alternatively, the spacing between different ones of the fingers 372 may be different.
The mating connector may also include a lower row of contacts, in which case, lower contacts 400 may additionally be received within the housing 302 and electrically connected to the host board 106. The lower contacts 400 are loaded into the housing 320 through the front 304 of the housing 302. In an alternative embodiment, the lower contacts 400 may be loaded into the housing 320 through the rear 306 in a similar manner as the upper contacts 320.
The signal contact 356 is held in the housing 302 by the retention plug 324. For example, during assembly, the signal contact 356 is loaded through the rear 306 of the housing 302 into the corresponding groove 330 (shown in
In an exemplary embodiment, the ground contact 358 includes a retention barb 410 extending forward from the post 340. Optionally, the retention barb 410 may be aligned with the channel portion 346. The retention barb 410 is received in an aperture 412 formed in the housing 302. The retention barb 410 frictionally engages the walls defining the aperture 412 to hold the ground contact 358 within the housing 302.
When assembled, the finger 372 covers a portion, such as the channel portion 346, of the post 340 such that the finger 372 is positioned between the post 340 and an adjacent post 340 of an adjacent contact 320. As such, portions of adjacent contacts 320 are separated from one another by the dielectric material of the finger 372. As illustrated in
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.