Coaxial cable connector

Information

  • Patent Grant
  • 6530808
  • Patent Number
    6,530,808
  • Date Filed
    Tuesday, October 17, 2000
    24 years ago
  • Date Issued
    Tuesday, March 11, 2003
    21 years ago
Abstract
An electrical connector member for a coaxial cable. The connector member comprises a first section and a second section. The first section has two or more portals therein, each portal adapted to guide an indentor of a crimping tool into a predetermined position over a crimp area of an electrical contact in the member. The second section includes a conductor receiving section of the electrical contact, the conductor receiving section having a diameter adapted to receive a center conductor of the cable. Each crimp area is located on the conductor receiving section, wherein an electrical connection is formed by crimping the electrical contact to the conductor at each crimp area using the indentors. The crimped connection provides a substantially matched impedance in that section of the connector.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to RF coaxial cable connectors and more particularly to a coaxial cable connector having improved voltage standing wave ratio through minimal impedance mismatch.




2. Brief Description of Earlier Developments




In most coaxial connector designs, it is a common practice to either crimp or solder the center conductor of the cable before assembling the center contact inside the connector. Crimping the center contact is a desirable termination method due to the lower applied cost of the cable assembly. Examples of crimping an electrical terminal to an exposed end of an inner conductor of a coaxial cable can be found in U.S. Pat. Nos. 5,273,458 and 5,490,801. In these cases, the center contact of the connector is terminated to the coaxial cable conductor via a crimping tool before assembly within the outer conductor and the dielectric member. However, in connector designs that incorporate a center contact pre-assembled with the remainder of the connector, termination must be made through portals in the outer conductor shell of the assembly. Termination of the center conductor of the coaxial cable in these designs can also be either crimp or solder. Methods of crimping through portals are described in U.S. Pat. Nos. 3,297,978, 4,047,788, 4,096,627. However, portal style crimps described to date have worse RF performance levels, due to the impedance mismatch effects of the portals. U.S. Pat. Nos. 3,297,978; 4,047,788; 4,096,627 describe the crimping of the center contact of the connector through opposed crimp portals, but fail to address the resulting electrical effects of the crimped connector. With the increased need for higher frequency ranges to support for example the expanding wireless communications markets, RF connectors used in telecommunication systems are required to operate at higher frequency ranges and with lower losses to make these systems function at their peak performance. Therefore, it would be desirable to be able to connect a coaxial cable conductor to a conductor receiving member via portals in the outer conductor shell of the connector, while at the same time optimizing the impedance of the connector as well as enhancing the overall RF performance of the connector, which are results not achieved or realized using any of the conventional connectors.




SUMMARY OF THE INVENTION




The present invention is directed to in a first aspect, an electrical connector member for a coaxial cable. In one embodiment, the connector member comprises a first section and a second section. The first section has two or more portals therein, each portal adapted to guide an indentor of a crimping tool into a predetermined position over a crimp area of an electrical contact in the member. The second section includes a conductor receiving section of the electrical contact, the conductor receiving section having a diameter adapted to receive a center conductor of the cable. Each crimp area is located on the conductor receiving section, wherein an electrical connection is formed by crimping the electrical contact to the conductor at each crimp area using the indentors. The crimped connection provides a substantially matched impedance in that section of the connector.




In another aspect, the present invention is directed to an electrical connector member for a coaxial cable. In one embodiment, the member comprises a first section having four portals and a second section including a conductor receiving section of an electrical contact in an interior section of the connector. Each portal is adapted to align a corresponding indentor of a crimping tool over a predetermined crimp area on the electrical contact. Each indentor is aligned adjacent to its respective portal as the connector member is inserted into the positioner of the crimping tool. The conductor receiving section has a diameter adapted to accommodate a center conductor of the cable. Preferably, the contact is adapted to be assembled in the connector member before a crimping operation. In the preferred embodiment, the crimp on each crimp area forms an electrical connection between the contact and the conductor and provides a substantially matched impedance for the crimp section of the connector.




In another aspect, the present invention is directed to a method of making a crimp-style coaxial electrical connector assembly having a generally uniform impedance. In one embodiment, the method comprises providing a coaxial electrical connector having an inner conductor, an outer conductor and a dielectric element separating the inner and outer conductor. A coaxial cable with a center conductor is provided and the inner conductor is engaged with the center conductor. The inner conductor is crimped to the center conductor through at least two openings in the outer conductor. The crimping step creates an area of impedance mismatch on the connector that is compensated for to provide the generally uniform impedance across the connector.




In a further aspect, the present invention is directed to a coaxial electrical connector with an inner conductor crimped to a center conductor of a coaxial cable through an outer conductor. In one embodiment, the improvement comprises the outer conductor having an inner diameter selected to compensate for an impedance mismatch created by the crimp, so that the connector has a generally uniform impedance thereacross.











BRIEF DESCRIPTION OF THE DRAWINGS




The foregoing aspects and other features of the present invention are explained in the following description, taken in connection with the accompanying drawings, wherein:





FIG. 1

is an exploded, perspective view of a connector sub-assembly incorporating features of the present invention.





FIG. 2

is an elevational view of a portion of the connector sub-assembly shown in

FIG. 1

for purposes of highlighting the dimensions of a portal.





FIG. 3

is a cross-sectional view of the connector sub-assembly taken along line III—III in FIG.


5


.





FIG. 4

is a cross-sectional view of the front end of the connector sub-assembly of

FIG. 1

taken along the line A—A before the crimping step.





FIG. 5

is a partial cross-sectional view of the connector sub-assembly of

FIG. 1

taken along the line A—A before the crimping step.





FIG. 6

is a cross-sectional view of an assembled (i.e. after the crimping step) connector sub-assembly incorporating features of the present invention.





FIG. 7

is a cross-sectional view of a mated connector assembly incorporating features of the present invention on both connectors.





FIG. 8

is an exploded, perspective view of a crimping tool assembly incorporating features of the present invention.





FIG. 9

is a partial cross-sectional view of the locator portion of the crimping tool assembly of

FIG. 8

taken along the line z—z.





FIG. 10

is an elevational view of the components of a connector sub-assembly of the present invention partially inserted into the crimp tool.





FIG. 11

is an elevational view of a connector sub-assembly of the present invention fully inserted into the crimp tool, but before the crimping step, including a partial cross-sectional view of the locator portion of the positioner and the crimp tool.





FIG. 12

is a perspective view of one embodiment of a connector sub-assembly incorporating features of the present invention inserted into a positioner device and before the indentors enter the portals for crimping.





FIG. 13

is a cross-sectional view of a connector sub-assembly fully inserted into the crimp tool during the crimping step, i.e. showing the indenters crimping the contact to the conductor.





FIGS. 14 and 15

are graphical representations of test data for a connector sub-assembly incorporating features of the present invention.





FIGS. 16 and 17

are graphical representations of test data for a connector sub-assembly incorporating a solder termination of the coaxial conductor.





FIG. 18

is an exploded, perspective view of a connector sub-assembly of the prior art.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to

FIG. 1

, there is shown an exploded perspective view of a connector sub-assembly


6


incorporating features of the present invention. Although the present invention will be described with reference to the single embodiment shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used.




In one embodiment, the connector


6


can be made from multiple machined pieces. Generally, the front end


48


and the back end


60


are adapted to be mechanically and electrically coupled together. Referring to

FIGS. 1

,


5


and


6


, the flange


144


can seat circumferentially against a complimentary portion


96


of the back end


60


. In one embodiment, the front end


48


and back end


60


may be coupled together by soft soldering the sub-assemblies together. In an alternate embodiment, the front end


48


and the back end


60


may be coupled together using any suitable electrical and mechanical connection method or device. In an alternate embodiment, the connector


6


can be manufactured as a one-piece connector. The front end


48


can include a pin or socket assembly adapted for mating with a complimentary connector assembly. The back end


60


can include two or more portals


68


, and a hollow bore


58


that is adapted to receive a coaxial cable.




The connector


6


is adapted to allow the center conductor of the coaxial cable to be connected, both electrically and mechanically, to a conductor receiving member


26


of the connector


6


, the connection optimizing the impedance of the connector as well as the RF performance of the connector. In this embodiment, the conductor receiving member


26


can be crimped to the center contact of the coaxial cable. It is a feature of the present invention to provide an improved mechanism and method of crimping a contact to a conductor through a portal.




As shown in

FIGS. 1

,


5


and


6


, the connector


6


can include two or more portals


68


extending through the back end


60


of the connector


6


into a hollow section or bore


56


. Each portal


68


provides access for insertion of an indentor


102


of a crimping tool


130


as shown in

FIGS. 8 and 12

. The design of each portal


68


is such that a subsequent crimp exerted by the crimping tool places a crimp


22


in a precise location on the conductor receiving member


26


as shown in FIG.


6


. It is a feature of the present invention that by locating a crimp in a precise location on the conductor receiving member


26


, by selecting the dimensions of the outer shell and each portal, and by using a crimp ferrule, that the impedance of the connector is optimized and the overall RF performance of the connector


6


is enhanced. These are significant improvements and enhancements that are not realized in any prior portal connector design.




As shown in

FIGS. 1 and 6

, connector


6


comprises plug (male) connector. Alternatively, the connector


6


may also take the form of an electrical receptacle (female) connector that is adapted to mate with the plug connector


6


of

FIG. 1

, as depicted in FIG.


7


. Once cables


38


are secured thereto, plug connector


6


A and receptacle connector


6


B are secured within a housing R and housing H, respectively as shown in FIG.


7


. Plug connector


6


A mounts to motherboard MB and receptacle connector


6


B mounts to daughter card DC.




The connector


6


can include a hollow bore


58


at one end of the back end


60


. The hollow bore


58


is generally adapted to be inserted between certain layers of a coaxial cable as described below. As shown in

FIG. 6

, a coaxial cable generally has an outer layer or jacket


40


covering an electrically conducting shielding layer


42


, which in turn covers a dielectric or insulation layer


44


. In the central portion of the cable


38


, and covered by the dielectric layer


44


, is an electrically conducting center conductor


46


. In one embodiment, the coaxial cable


38


can be 26 AWG coaxial cable, such as for example ALPHA WIRE CO. P/N 9316, M17/113-RG316. However, in alternate embodiments, the coaxial cable


38


can be any suitable cable for high frequency communication applications.




The bore


58


extends between the dielectric layer


44


and the shielding layer/cable braid


42


. Referring to

FIG. 5

, an inner diameter Ø


1


of the hollow bore


58


is generally sized just large enough to accommodate a center conductor


46


and a dielectric layer


44


of a coaxial cable


38


. In one embodiment, the inner diameter Ø


1


of the hollow bore


58


can be approximately 0.063 inches (1.600 millimeters) in order to accommodate a coaxial cable having a dielectric diameter of approximately 0.060 inches (1.524 millimeters). In an alternate embodiment, the inner diameter Ø


1


of the hollow bore


58


can be sized to any suitable dimension in order to accommodate a desired coaxial cable


38


. The knurled exterior surface


82


of back end


60


abuts cable braid/shielding layer


42


.




Referring to

FIGS. 1 and 5

, in one embodiment, the back end


60


of the connector


6


can include a tapered diameter


66


. The tapered diameter


66


can be approximately between the section


64


of back end


60


that includes the portals


68


and the section


62


that includes the hollow bore


58


. As shown in

FIGS. 1

,


5


and


6


, an outer surface of the section


62


can include a conductive crimping surface


82


over which the conductive shielding layer


42


of the cable


38


can be secured. In one embodiment, the crimping surface


82


can comprise a knurled surface. Once bore


58


is inserted between insulation layer


44


and shielding layer


42


of cable


38


, a crimp ferrule


80


can be positioned over the back end


60


of connector


6


in order to secure the shield layer


42


positively to the connector


6


. In an alternate embodiment, any suitable surface and manner of connection can be used to establish a mechanically and electrically secure conductive bond between the connector


6


and the shield layer


42


.




The crimp ferrule


80


generally comprises a conductive member adapted to secure, both mechanically and electrically, the cable


38


and the shield layer


42


to the connector


6


. Referring to

FIG. 6

, in this embodiment, the crimp ferrule


80


covers the portals


68


and provides shielding effectiveness against radio frequency (“RF”) leakage.




Referring to

FIGS. 1

,


5


and


6


, the connector


6


may also include a chamfered edge


78


along the leading edge of back end


60


near hollow bore


58


where the cable


38


is inserted. The chamfered edge


78


can be used to separate the shield layer


42


from the dielectric layer


44


upon insertion of the coaxial cable


38


into the connector


6


.




In one embodiment, the connector


6


is symmetrical and can include four portals


68


, also referred to as portholes, each portal


68


being spaced around a circumference of the back end


60


of connector


6


at approximately 90° from an adjacent portal. In an alternate embodiment, the connector


6


can include any suitable number of portals


68


. Referring to

FIG. 2

, each portal


68


generally has a length L


1


greater than its width W


3


. In one embodiment, the length L


1


of a portal


68


can be approximately 0.1700 inches (4.318 millimeters) while the width W


3


of a portal


68


can be approximately 0.0650 inches (1.651 millimeters). In an alternate embodiment, the length and width of a portal


68


can be any suitable dimension. Referring to

FIG. 12

, the size of the portals


68


closely mirrors the size of the indenters


102


in the crimping tool


130


in order to guide the indenters


102


into the connector


6


and to an aligned position. In the aligned position, each indentor


102


is adapted to apply a crimp


22


in a predetermined location on the conductor receiving member


26


as shown in FIG.


6


. The design of each portal


68


, including its length, width and position, are generally adapted to optimize the impedance of the connector and to enhance its overall RF performance. The crimp tool will be described in more detail below.




Generally, as shown in

FIG. 3

, the back end


60


of the connector


6


has an interior section


56


. The inner diameter of interior section


56


is identified as Ø


2


. Back end


60


also includes two or more portals


68


, with a width identified as W


3


. Centrally interposed within section


56


is the conductor receiving member


26


with an outer diameter of Ø


4


. As is known in the industry, the impedance of a coaxial structure is a function of the inner diameter of the outer conductor, the outer diameter of the inner conductor, and the dielectric constant of the material that separates the inner and outer conductors. It is also known that the inclusion of slots in either the inner or outer conductor introduce disturbances in the coaxial structure, resulting in impedance changes in these areas. Referring to

FIG. 3

in the current embodiment, the inner diameter Ø


2


of the shell


50


in section


56


can be approximately 0.1310 inches (3.3274 mm). Also shown in

FIG. 3

are portals


68


. In this embodiment, as noted earlier, the width W


3


of the portals


68


can be approximately 0.065 inches (1.651 mm). Referring to

FIGS. 1

,


5


and


6


, the conductor receiving member, which generally comprises a hollow bore adapted to accommodate the center conductor


46


of the cable


38


, has, in this embodiment, an outer diameter Ø


4


of approximately 0.0625 inches (1.5875 mm). It is a feature of the present invention that the combination of the inner diameter Ø


2


of section


56


, the outer diameter Ø


4


of conductor receiving member


26


, and the width W


3


of portals


68


are adapted such as to optimize the impedance of the connector and enhance the overall RF performance. However, in an alternate embodiment, such as those encountered when using a coaxial cable of either smaller or larger dimensions, the outer diameter Ø


4


of conductor receiving member


46


, the inner diameter Ø


2


of section


56


of back end


60


, and the width W


3


of portals


68


in back end


60


can be any suitable dimension, provided that the combination of dimensions are adapted to achieve the optimized RF performance characteristics of a connector incorporating features of the present invention.




Referring to

FIGS. 1

,


5


and


6


, the conductor receiving member


26


extends into the interior section


56


of connector


6


. The conductor receiving member


26


generally comprises a hollow bore adapted to accommodate the center conductor


46


of the cable


38


. As shown in

FIG. 5

, an outer diameter Ø


4


of the conductor receiving member


26


is generally just large enough to accommodate the center conductor


26


. In one embodiment, the outer diameter Ø


4


of the conductor receiving member


26


is approximately 0.0625 inches (1.5875 millimeters.). However, in an alternate embodiment, the outer diameter Ø


4


of conductor receiving member


26


can be any suitable dimension. It is a feature of the present invention that the outer diameter Ø


4


of the conductor receiving member


26


be adapted, in conjunction with the design of back end


60


(including portals


68


), to optimize the impedance of the connector and enhance the overall RF performance. Referring to

FIG. 6

, the conductor receiving member


26


is adapted to be crimped to the center conductor


46


at crimp points


22


in order to establish a secure mechanical and electrically conductive connection. The crimps are caused to be precisely located at the crimp areas


22


by the alignment of the indentors


102


in each of the portals


68


as shown in FIG.


12


. As will be described in more detail below in conjunction with

FIGS. 9-13

, a stop shoulder


110


in positioner


100


locates connector


6


relative to indentors


102


for the crimping step. By locating the crimp areas


22


in precise locations on the member


26


, the impedance of the connector is optimized and the VSWR of the connector is greatly improved, which are results not realized in other portal crimp designs. It is a feature of the present invention that the design of the portals


68


positions the indenters


102


in the aligned position to locate the crimps over the predetermined crimping areas


22


of connector


6


. The location of the crimp is a factor in the impedance matching and VSWR performance of the connector


6


.




As shown in

FIGS. 1 and 3

, the interior of the connector


6


in the front end


48


is generally cylindrical. Referring to

FIGS. 4 and 6

, a stepped diameter


91


in the front end


48


provides a circumferential shoulder stop


94


within the generally hollow interior


10


against which a generally cylindrical dielectric insert


12


is seated when assembled into the interior


10


. The dielectric insert


12


is generally cylindrical in form and is provided with a central bore


14


having a chamfered entryway


16


at the receptacle end


18


. The electrical contact


20


is generally supported within the bore


14


before insertion into front end


48


. In one embodiment, the contact


20


may also be provided with a reduced neck portion


24


retained in a relatively reduced neck portion


28


of the bore


14


to help secure the contact


20


within the bore


14


.




The front end


48


of connector


6


may also include a pair of shoulder stops


8


on the exterior shell


86


of the front end


48


. The exterior shell


86


generally comprises a section of the conductive shell


50


. Shoulder stops


8


serve to seat connector


6


against a complimentary shoulder stop


110


in a locator


104


of the crimping tool as shown in

FIG. 11

during the crimping step.




A crimping tool


130


and positioner


100


incorporating features of the present invention are shown in FIG.


8


. The crimping tool


130


generally comprises two handles


132


,


134


that are manually manipulated by squeezing the handles


132


,


134


. Tool


130


may also include a set of indenters secured within crimping port


133


adapted to close against the connector


6


at crimp areas


22


to crimp the conductor


46


to the member


26


. In this embodiment, the tool


130


comprises a standard military commercial hand tool M22520/1-01 or part number AF8 sold by Daniels Manufacturing Corporation, also described in Military Specification MIL-C-22520/1 page 1. In an alternate embodiment, tool


130


could comprise any suitable device adapted to crimp conductor


46


to conductor receiving member


26


at crimp areas


22


. As shown in

FIGS. 6 and 13

, the crimp at crimp areas


22


is adapted to provide a secure mechanical and electrically conductive connection between conductor


46


and conductor receiving member


26


. It is a feature of the present invention to form a high performance, low loss electrical connection between the conductor


46


and contact


20


in a connector


6


, while lowering the applied cost of the connector and cable assembly. Referring to

FIGS. 8

,


12


and


13


, the indenters are adapted to close against a connector


6


(with a cable


38


placed therein) inserted into the tool from a first side


135


. The indenters may be arranged so that two pairs of opposed indenters dies provide pairs of indents at four equally spaced crimp areas


22


.




A set of indenters


102


, is shown in

FIGS. 8-13

. Positioner


100


is generally adapted to precisely align and position connector


6


within the tool


130


for the crimping operation. Positioner


100


is mountable to tool


130


on side


136


of tool opposite to crimping port


133


. Locating pin


108


and retaining screws


106


are adapted to be received in complimentary receptacles on side


136


of tool


130


in order to align and secure positioner


100


to tool


130


. Positioner


100


can also include a spring-loaded locator shaft


104


that is adapted to receive connector


6


. Referring to

FIG. 9

, locator shaft


104


is generally cylindrical and comprises first section


111


, a second section


113


and a third section


115


. Locator shaft


104


is generally adapted to be inserted into aperture


116


of positioner


100


. The second section


113


generally has a smaller diameter than the first or third sections


111


,


115


.




Locator shaft


104


can include a reduced-diameter forward section


117


defining a forwardly facing ledge


114


which abuts a correspondingly rearwardly facing ledge


122


defined by a reduced diameter forward portion


119


of aperture


116


within which forward section


117


of shaft


104


is to be disposed. Locator shaft


104


can also include an annular collar


118


at its rearward end that is disposed with an enlarged rearward aperture section


120


of aperture


116


. The rearwardly facing ledge


122


is defined between the rearward aperture section


120


and aperture


116


to retain locator shaft


104


assembled to positioner


100


. Rear end


124


of locator shaft


104


is spring biasedly engaged by compression spring


126


mounted within rearward aperture section


120


and held therein by threaded insert


128


. Alternatively, any suitable means can be used to retain locator shaft


104


in aperture


116


. Locator shaft


104


described above receives plug connector


6


A. A modified shaft not shown is used to receive receptacle connector


6


B. Like shaft


104


, the modified shaft receives receptacle


88


to precisely position portals


68


to accept indenters


102


.




Referring to

FIGS. 8

,


10


and


11


, as positioner


100


initially mounts to tool


130


, leading edge


112


of locator shaft


104


abuts a stop shoulder


150


. As the mounting of positioner


100


to tool


130


continues, the locator shaft


104


is pushed back against the force of spring


126


as shown in FIG.


10


. In other words, spring


126


ensures that locator shaft


104


maintains an abutting relationship with stop shoulder


150


. Due to this arrangement, locator shaft


104


is precisely positioned relative to indentors


102


. With the positioner fully mounted to tool


130


, connector


6


can be precisely crimped to coaxial cable


38


as will be explained in more detail below.




Referring to

FIGS. 10 and 11

, locator shaft


104


can also include a stop shoulder


110


adapted to abut to a complimentary stop shoulder


8


of connector


6


when the connector


6


is inserted into the shaft


104


. When connector


6


abuts stop shoulder


110


, connector


6


is accurately located in the positioner


100


for a crimping operation. Since positioner


100


is accurately located relative to indentors


102


, connector


6


is also accurately positioned relative to indentors


102


.

FIGS. 8 and 10

are illustrative of the general assembly of connector


6


and cable


38


prior to insertion into the tool


130


.





FIG. 11

illustrates the basic positioning of connector


6


inserted into a locator shaft


104


with a cable


38


inserted into the connector


6


. Referring to

FIG. 6

, generally, the cable


38


is inserted into the connector


6


by exposing and flaring the cable braid


42


, then feeding the exposed conductor


46


and dielectric layer


44


through the hollow bore


58


. The conductor


46


is funneled into the conductor receiving member


26


and the braid


42


travels outside bore


58


by the chamfer portions


25


as shown in FIG.


6


. After the cable


38


has been inserted into the connector


6


and the conductor receiving member crimped as described herein, a crimping ferrule


80


is placed over the back end


60


as shown in FIG.


6


and crimped thereto, preferably, with a subsequent crimp process performed with a known crimping tool.




For crimping of the center conductor


46


, a connector


6


and cable


38


are inserted into positioner


100


and tool


130


as shown in FIG.


11


. Referring to

FIG. 12

, the portals


68


each engage an indentor


102


upon actuation of the tool


130


. By squeezing the handles


132


,


134


of tool


130


, the indenters


102


are caused to crimp contact


20


at crimp locations


22


, causing the crimping of conductor


46


as shown in FIG.


13


.




Referring to

FIGS. 11 and 13

, in an example of one embodiment incorporating features of the present invention, when properly positioned against stop shoulder


150


of tool


130


, an outer edge


112


of locator shaft


104


is a distance D


5


of approximately 0.126 inches (3.2004 mm) from the centerlines of indenters


102


, as described in Military Specification MIL-C-22520/1.




A cross-sectional view of a mated pair of complimentary connectors


6


A and


6


B is shown in FIG.


7


. Connector


6


A comprises a plug


36


, while connector


6


B comprises a receptacle


34


. As seen in

FIG. 7

, the connectors


6


A,


6


B could be mated, so that a gap L exists between connector housings R, H. Preferably, gap L is approximately 0.045 inches (1.143 millimeters). When connector


6


A is properly mated with the connector


6


B, a nominal distance D


1


between a far end of retention clips


90


on each of the connectors


6


A and


6


B can be approximately 0.578 inches (14.68 millimeters).





FIGS. 14 and 15

are graphical representations of actual performance test data for connectors


6


A and


6


B incorporating features of the present invention assessing connector loss in terms of VSWR versus frequency, in gigaHertz. The tests were performed with the connectors in the mated condition shown in FIG.


7


. The connector housings were 0.045″ (1.143 mm) from a nominal, or fully mated, position.





FIGS. 16 and 17

are graphical representations of actual performance test data of a prior art connector


6


′, shown in

FIG. 18

, when mated with a complementary prior art connector, where the conductor


46


of a typical cable


38


is soldered to contact


26


′.




Connector


6


′ has an asymmetric back end


60


′. Approximately half of back end


60


′ is removed, creating an opening


68


′ that reveals center contact


26


′. Center contact


26


′ includes a solder port


27


′. Once the center conductor (not shown) of the coaxial cable (not shown) is placed within center contact


26


′, solder (not shown) is introduced into solder port


27


′. The solder fuses the center conductor of the coaxial cable to center contact


26


′. Finally, a ferrule (not shown) is placed over opening


68


′ and crimped to the braid (not shown) of the coaxial cable. As with

FIGS. 14 and 15

, these tests were also performed with the connectors in a mated condition such as that shown in FIG.


7


. In other words, the connector housings were arranged 0.045″ (1.143 mm) from a nominal, or fully mated, position. The test data demonstrates the substantial improvement in terms of electrical performance of the connector


6


of the present invention (

FIGS. 14 & 15

) over a solder type conductor termination (

FIGS. 16 & 17

) used with connector


6


′.




In one embodiment, referring to

FIGS. 6 and 7

, the connector


6


is adapted to be used in high frequency applications, such as for example between approximately 1 and 5 gigahertz (“gHz”). Other applications may include the telecommunications industry where a low loss connection is desired.




The size, shape and location of the portals


68


, the outer diameter of the center contact


26


and the inner diameter of shell


50


are each a factor in the performance of the assembled connector


6


. By placing connector


6


at stop shoulder


110


, of positioner


100


, which itself has been placed against stop shoulder


150


of tool


130


, indenters


102


precisely locate the crimp in the connector


6


. The present invention minimizes signal reflections and compensates for those areas of impedance mismatch that cannot otherwise be eliminated within the connector. Thus, the present invention enhances the overall performance of the connector without sacrificing ease of termination.




It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.



Claims
  • 1. An electrical connector member for a coaxial cable comprising:a first section having two or more portals formed therein, each portal adapted to guide an indentor of a crimping tool into a predetermined position over a crimp area of a conductor receiving section of an electrical contact extending into the first section; and a second section including a conductive outer shell electrically coupled to the first section; and a dielectric material enclosed by the outer shell in the second section supporting the electrical contact in a central bore of the dielectric material, the dielectric material not surrounding the conductor receiving section, the conductor receiving section having a diameter adapted to receive a center conductor of the cable, wherein an electrical connection formed by crimping the electrical contact to the conductor using the indentors extending through the portals provides a substantially matched impedance in that section of the connector; a void defining an area in the first section surrounding the conductor receiving section; and a crimp ferrule adapted to be inserted over the first section to electrical and mechanically secure a coaxial shield conductor to the connector member and to cover each portal opening to provide an electrical shield against RF leakage from the void area surrounding the conductor receiving section.
  • 2. The connector member of claim 1 wherein the first section and the second section of the member are mated together forming an electrically conductive and mechanically secure connection, and the coaxial cable is crimped in the connector member prior to insertion of the connector member into a respective housing.
  • 3. The connector member of claim 1 wherein the first section and the second section are machined as a one-piece connector member.
  • 4. The connector member of claim 1 wherein the first section includes four portals, each portal being spaced at a location that is 90° from an adjacent portal.
  • 5. The connector member of claim 1 wherein required impedance in a crimp section of the connector member formed by the crimping is approximately 50 ohms.
  • 6. The connector member of claim 1 wherein the connector member is adapted to propagate a signal having a frequency in the range of 1 to 5 gigaHertz (gHz).
  • 7. The connector member of claim 1 wherein a location of a center point of the crimp area on the conductor receiving section is approximately 0.126 inches (3.200 mm) from the front edge of a locator device adapted to position the connector member in the tool.
  • 8. An electrical connector member for a coaxial cable comprising:a first section having two or more portals formed therein, each portal adapted to guide an indentor of a crimping tool into a predetermined position over a crimp area of a conductor receiving section of an electrical contact extending into the first section; and a second section including a conductive outer shell electrically coupled to the first section; and a dielectric material enclosed by the outer shell in the second section supporting the electrical contact in a central bore of the dielectric material, the dielectric material not surrounding the conductor receiving section, the conductor receiving section having a diameter adapted to receive a center conductor of the cable, wherein an electrical connection formed by crimping the electrical contact to the conductor using the indentors extending through the portals provides a substantially matched impedance in that section of the connector; a void defining an area in the first section surrounding the conductor receiving section; and a retention clip located on a housing of the second section adapted to retain the assembled and crimped connector member in a connector housing.
  • 9. An electrical connector member for a coaxial cable comprising:a first section having two or more portals formed therein, wherein each portal extends from a front portion of the first section through a tapered edge along a rear portion of the first section to form a respective groove in the tapered edge, wherein when the connector member is inserted into the crimping tool, the groove aligns the indentors in each portion, and wherein each portal is adapted to guide an indentor of a crimping tool into a predetermined position over a crimp area of a conductor receiving section of an electrical contact extending into the first section; a second section including a conductive outer shell electrically coupled to the first section; and a dielectric material enclosed by the outer shell in the second section supporting the electrical contact in a central bore of the dielectric material, the dielectric material not surrounding the conductor receiving section, the conductor receiving section having a diameter adapted to receive a center conductor of the cable, wherein an electrical connection formed by crimping the electrical contact to the conductor using the indentors extending through the portals provides a substantially matched impedance in that section of the connector; and a void defining an area in the first section surrounding the conductor receiving section.
  • 10. An electrical connector member for a coaxial cable comprising:an electrically conductive shell; an electrical contact extending along a portion of a center bore of the shell supported by a first dielectric material, the conductive shell comprising: a first section including four portals therein, each portal adapted to align a corresponding indentor device over a respective portion of a conductor receiving section of the electrical contact; a second section electrically connected to the first section, the second section including the dielectric material inserted therein supporting the electrical contact, the conductor receiving section extending out of the first dielectric material and into the first section wherein a center conductor of the cable is adapted to be received through the first section and crimped to the conductor receiving portion inside of the first section; a crimp ferrule adapted to be inserted over the first section to electrically and mechanically secure a shield conductor of the cable to the connector member and to cover each portal opening to provide a shield against RF leakage; and wherein a void defines an area surrounding a crimped section of the electrical contact and an impedance of the crimped section is substantially matched to an impedance of the cable.
  • 11. The connector member of claim 10 wherein a centerline between crimp points applied by each indentor device to the conductor receiving section is approximately 0.126 inches (3.2004 mm) from an outer edge of the locator shaft.
  • 12. A connector assembly for a coaxial cable comprising:a plug connector mated to a receptacle connector, wherein each of the plug connector and receptacle connector comprises: a conductive shell comprising a first section and a second section, the first section housing an electrical contact disposed within a center bore of a dielectric material inserted therein; a conductor receiving section of the contact extending from the dielectric material into the second section and adapted to receive a center conductor of a first coaxial cable, the second section including four portals in the shell around the conductor receiving section, each portal adapted to receive an indentor of a crimping tool for crimping the conductor receiving section to the center conductor in at least four aligned locations, the second section further including a bore adapted to receive a cable dielectric and center conductor of the first cable on the inside of the bore and a cable shield on an outside of the bore, wherein a void defines an area around a crimp section of the conductor receiving section; and a retention clip on each first section adapted to retain the respective plug connector and receptacle connector in a respective housing member, wherein when the plug connector is coupled to the receptacle connector a nominal distance between a far end of each retention clip is 0.578 inches (14.68 mm).
  • 13. An electrical connector for a coaxial cable, the electrical connector comprising:an electrical contact having a conductor receiving section, the conductor receiving section comprising a crimp area; a first portion having a plurality of portals, the conductor receiving section of the electrical contact extending into an open area of the first portion, wherein each portal is adapted to guide an indentor of a crimping tool into a predetermined position over the crimp area of the conductor receiving section of the electrical contact; a second portion electrically coupled to the first portion, the second portion including a conductive outer shell; a dielectric member located inside the second portion and supporting the electrical contact therein, wherein an electrical connection formed by crimping the electrical contact to a center conductor of the coaxial cable using the indentors extending through the portals provides a substantially matched impedance; and a crimp ferrule adapted to be located over the first portion to secure a shield conductor of the coaxial conductor to the first portion and to cover the portals, wherein the crimp ferrule is adapted to provide an electrical shield against RF leakage from the open area at the conductor receiving section.
  • 14. A coaxial cable electrical connector comprising:an electrical contact; a first portion having a plurality of portals formed therein, wherein the electrical contact extends into an open area of the first portion, and wherein the portals are each adapted to guide an indentor of a crimping tool into a predetermined position over a crimp area of a conductor receiving section of the electrical contact; a second portion electrically coupled to the first section, the second portion comprising a conductive outer shell; a dielectric member located in the outer shell in the second section, the dielectric member supporting the electrical contact therein, wherein an electrical connection formed by crimping the electrical contact to a center conductor of a coaxial cable using the indentors extending through the portals provides a substantially matched impedance; and a retention clip located on the second portion, the retention clip being adapted to retain the coaxial cable electrical connector to a connector housing.
  • 15. A coaxial cable electrical connector comprising:an electrical contact; a first section having a plurality of portals formed therein, wherein the electrical contact extends into an open area of the first section, wherein each portal extends through a portion of a tapered edge of the first section to form a respective groove in the tapered edge, wherein each portal is adapted to guide an indentor of a crimping tool into a predetermined position over a crimp area of a conductor receiving section of the electrical contact, and wherein, when the first section is inserted into the crimping tool, the grooves are adapted to align the indentors with the first section; and a second section electrically coupled to the first section, the second section comprising a conductive outer shell.
US Referenced Citations (9)
Number Name Date Kind
3221290 Stark et al. Nov 1965 A
3297978 Stark Jan 1967 A
3366920 Laudig et al. Jan 1968 A
4047788 Forney et al. Sep 1977 A
4096627 Forney et al. Jun 1978 A
5066249 Doye et al. Nov 1991 A
5273458 Fisher, Jr. et al. Dec 1993 A
5490801 Fisher, Jr. et al. Feb 1996 A
5994975 Allen et al. Nov 1999 A