Patent Publication Number: US-8986042-B2

Title: Square RF electrical contact and method of manufacturing the same

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical contacts and more specifically, the present invention relates to square radio frequency (RF) electrical contacts having a center conductor, an insulating layer, and a conductive sheath having substantially square cross-sections. 
     2. Description of the Related Art 
     Electrical contacts are used to place electrical devices, such as printed circuit boards, in communication with one another. An electrical contact includes two portions, one portion of which is arranged to be connected to a first electrical device and the second portion of which is arranged to be connected to a second electrical device to be put into communication with the first device. To connect the two devices, the two portions of the electrical contacts are mated together. 
     One conventional type of RF electrical contact is a coaxial contact. A coaxial contact has a substantially cylindrical cross-section, and includes a center conductor, an insulating layer, and a conductive sheath. One problem with conventional coaxial contacts is that, due to the substantially cylindrical cross-sectional shape, conventional coaxial contacts must be screw machined, which is an expensive, time consuming process and which requires very tight manufacturing tolerances. Thus, conventional coaxial contacts are relatively expensive to manufacture. 
     Further, screw machined RF connectors have a low cycle life due to high normal force and machined mating surfaces. In addition, screw machined RF connectors have virtually no misalignment allowance because they are circular and the contact beams do not allow for the mating connectors to be out of location. 
     SUMMARY OF THE INVENTION 
     To overcome the problems described above, preferred embodiments of the present invention provide an electrical contact which can be produced faster and at a reduced cost as compared to a coaxial contact, and which still maintains consistent geometry throughout the entire length of the mated stack height to reduce signal integrity discontinuities. 
     An electrical contact according to a preferred embodiment of the present invention includes a female portion including a conductive sheath, a dielectric disposed within the conductive sheath, and a center conductor extending through the dielectric, and a male portion including a conductive sheath, a dielectric disclosed within the conductive sheath, and a center conductor extending through the dielectric, wherein the female portion and the male portion are arranged to be engageable with one another, the conductive sheath, the center conductor, and the dielectric of each of the female portion and the male portion have a substantially square shape, each of the center conductors of the female portion and the male portion includes a contact portion arranged to be engaged with one another when the female portion and the male portion are engaged with one another, and the contact portion of each of the center conductors of the female portion and the male portion has a thickness of substantially half of a thickness of the remaining portions of the center conductors. 
     The contact portion of the center conductor of the male portion preferably has a width that is greater than a width of the contact portion of the center conductor of the female portion. 
     The conductive sheath of the female portion preferably has inner dimensions that are greater than outer dimensions of the conductive sheath of the male portion such that a space is provided between the conductive sheath of the female portion and the conductive sheath of the male portion. 
     Preferably, the dielectric of the female portion includes a block portion and a frame portion extending from the block-shaped portion, the frame portion has an opening extending therethrough, and the contact portion of the center conductor of the female portion is disposed adjacent to the opening in the frame-shaped portion. 
     Preferably, the block portion of the dielectric of the female portion includes a through-hole extending therethrough, the center conductor of the female portion includes at least one projection extending from an intermediate portion thereof, and the center conductor of the female portion extends through the opening in the block portion of the dielectric of the female portion such that the at least one projection is engaged with a side surface of the through-hole in the block portion of the dielectric of the female portion. 
     Preferably, the dielectric of the male portion includes a block portion and a support portion extending from the block portion, the support portion has a groove disposed in a surface thereof, and the contact portion of the center conductor of the male portion is disposed in the groove in the surface of the support portion. 
     The support portion of the dielectric of the male portion preferably includes an opening extending through the support portion from a surface of the groove to a surface of the support portion opposite to the surface in which the groove is disposed. 
     The female portion preferably includes a plurality of resilient arms arranged to resiliently engage an outer surface of the male portion when the female portion and the male portion are engaged with one another. 
     Preferably, the conductive sheath of the female portion includes an opening in an intermediate portion thereof, and the dielectric of the female portion includes a projection arranged to engage the opening in the conductive sheath of the female portion when the dielectric of the female portion is disposed in the conductive sheath of the female portion. 
     Preferably, the conductive sheath of the male portion includes an opening in an intermediate portion thereof, and the dielectric of the male portion includes a projection arranged to engage the opening in the conductive sheath of the male portion when the dielectric of the male portion is disposed in the conductive sheath of the male portion. 
     Preferably, the conductive sheath of the female portion includes a plurality of terminals extending from an intermediate portion thereof, and the plurality of terminals are arranged to be disposed and soldered in holes provided in a circuit board. 
     Preferably, the conductive sheath of the male portion includes a plurality of terminals extending from an intermediate portion thereof, and the plurality of terminals are arranged to be disposed and soldered in holes provided in a circuit board. 
     The conductive sheath of the female portion preferably includes a seam extending substantially in a longitudinal direction of the conductive sheath of the female portion at which two edges of the conductive sheath of the female portion are adjacent to one another. 
     The conductive sheath of the male portion preferably includes a seam extending substantially in a longitudinal direction of the conductive sheath of the male portion at which two edges of the conductive sheath of the male portion are adjacent to one another. 
     The edges of the conductive sheath of the male portion adjacent to one another preferably include complementary locking elements arranged to interconnect with one another. 
     A method of manufacturing an electrical contact according to another preferred embodiment of the present invention includes the steps of forming a conductive sheath by stamping a substantially flat metal plate into a desired shape, and subsequently forming the conductive sheath into a substantially square shape by a progressive die process, providing a center conductor having a substantially square cross sectional shape, forming a dielectric by overmolding a dielectric material into a substantially square shape around the center conductor such that the center conductor is embedded in the dielectric, the substantially square shape of the dielectric substantially corresponds to the substantially square shape of the conductive sheath, and disposing the dielectric including the center conductor embedded therein in the conductive sheath. 
     The step of forming the dielectric may be preferably performed by injection molding or insert molding. 
     In the step of forming a conductive sheath, a plurality of the conductive sheaths is preferably formed while being attached to a strip. 
     In the step of providing the center conductor, a plurality of center conductors is preferably attached to a strip. 
     In the step of forming a dielectric, a plurality of dielectrics is preferably formed on the plurality of center conductors attached to the strip. 
     Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the female portion of the electrical contact according to a preferred embodiment of the present invention. 
         FIG. 2  is a side view of the female portion of the electrical contact shown in  FIG. 1 . 
         FIG. 3  is another side view of the female portion of the electrical contact shown in  FIG. 1 . 
         FIG. 4  is a perspective view of a partially assembled portion of the female portion of the electrical contact shown in  FIG. 1 . 
         FIG. 5  is a side view of the dielectric of the female portion of the electrical contact shown in  FIG. 1 . 
         FIG. 6  is a perspective view of the center conductor of the female portion of the electrical contact shown in  FIG. 1 . 
         FIG. 7  is a perspective view of the male portion of the electrical contact according to a preferred embodiment of the present invention. 
         FIG. 8  is a side view of the male portion of the electrical contact shown in  FIG. 7 . 
         FIG. 9  is another side view of the male portion of the electrical contact shown in  FIG. 7 . 
         FIG. 10  is a perspective view of a partially assembled portion of the male portion of the electrical contact shown in  FIG. 7 . 
         FIG. 11  is a perspective view of the dielectric of the male portion of the electrical contact shown in  FIG. 7 . 
         FIG. 12  is a perspective view of the center conductor of the female portion of the electrical contact shown in  FIG. 7 . 
         FIG. 13  is a perspective view of the electrical contact according to a preferred embodiment of the present invention in a state in which the female portion and the male portion of the electrical contact are engaged with each other. 
         FIG. 14  is a sectional view of the electrical contact shown in  FIG. 13 . 
         FIGS. 15A and 15B  are views of female portions of electrical contacts being inserted into female electrical connectors according to a preferred embodiment of the present invention. 
         FIGS. 16A to 16D  are views of the female portions of the electrical contacts that have been inserted into the female electrical connector as shown in  FIGS. 15A and 15B . 
         FIGS. 17A to 17D  are views of male portions of electrical contacts that have been inserted into male electrical connectors according to a preferred embodiment of the present invention. 
         FIG. 18  is a view of the female electrical connector and the male electrical connector shown in  FIGS. 15A to 17D  in an arrangement to be mated with one another. 
         FIG. 19  is another view of the female electrical connector and the male electrical connector shown in  FIGS. 15A to 17D  in an arrangement to be mated with one another. 
         FIGS. 20A and 20B  are views of a first step of a method for manufacturing a female portion according to a preferred embodiment of the present invention. 
         FIGS. 21A and 21B  are views of a second step of a method for manufacturing a female portion according to a preferred embodiment of the present invention. 
         FIGS. 22A and 22B  are views of a third step of a method for manufacturing a female portion according to a preferred embodiment of the present invention. 
         FIGS. 23A and 23B  are views of a fourth step of a method for manufacturing a female portion according to a preferred embodiment of the present invention. 
         FIGS. 24A and 24B  are views of a fifth step of a method for manufacturing a female portion according to a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention will now be described with reference to  FIGS. 1 to 24B . In the preferred embodiments of the present invention, it is preferable to maintain a substantially square cross-sectional geometry of the center conductor, dielectric, and conductive sheath throughout the length of the contact. By maintaining the substantially square cross-sectional geometry of the center conductor, the dielectric, and the conductive sheath throughout the length of the contact, signal integrity discontinuities are minimized so as to achieve outstanding signal integrity performance. 
       FIGS. 1-6  show a female portion  20  of an electrical contact  10  or a partial portion of the female portion  20  according to a preferred embodiment of the present invention. 
     As seen in  FIGS. 1-6 , the female portion  20  preferably includes a center conductor  21  which extends through a dielectric  22 , and the dielectric  22  is disposed within a conductive sheath  23 . 
     As best seen in  FIG. 6 , the center conductor  21  includes an intermediate portion  213  connecting a tail portion  211  and a contact portion  212 . The intermediate portion  213  includes, for example, projections  213   a  disposed on opposite sides of the intermediate portion  213 . The projections  213   a  are arranged to be engageable with the dielectric  22  to fix the location of the center conductor  21  as shown, for example, in  FIG. 4 . However, any suitable fixing structure may be provided to prevent movement of the center conductor  21  with respect to the dielectric  22 . 
     The contact portion  212  of the center conductor  21  is preferably configured to have a thickness that is approximately half of the thickness of the tail portion  211  and the intermediate portion  213  to enable the contact portion  212  to engage with a contact portion  412  of the male portion  40 , which is described below. The contact portion  212  acts as a spring arm such that the contact portions  212  and  412  can be resiliently engaged with one another. The contact portion  212  preferably includes a substantially flat surface  212   a  extending along a portion of the contact portion  212  adjacent to the intermediate portion  213  and a curved surface  212   b  extending along the remaining portion of the contact portion  212 . The substantially flat surface  212   a  is configured to be engaged with a substantially flat surface of the contact portion  412  of the male portion  40 , and the curved surface  212   b  is configured to facilitate engagement of the contact portion  212  of the center conductor  21  of the female portion  20  with the contact portion  412  of the center conductor  41  of the male portion  40 , which is described below. In addition, the contact portion  212  preferably includes an end portion  212   c  that extends away from the substantially flat surface  212   a  of the contact portion  212 . In this preferred embodiment, the end portion  212   c  has an arc shape. However, the end portion  212   c  may have any suitable shape as long as it extends away from the substantially flat surface  212   a.    
     As best seen in  FIGS. 4 and 5 , the dielectric  22  is preferably overmolded with the center conductor  21 , such that the center conductor  21  is embedded in the dielectric  22 . The dielectric  22  includes a block portion  221  and a frame portion  222 . The projections  213   a  of the center conductor  21  are provided to prevent the center conductor  21  from moving with respect to the block portion  221  so as to fix the location of the center conductor  21  with respect to the dielectric  22 . Alternatively, the dielectric  22  may be formed by injection molding to have a through-hole extending therethrough, and the center conductor  21  may be press-fit into the through-hole. 
     The block portion  221  preferably includes a projection  221   a  arranged to be disposed in an opening  231  of the conductive sheath  23  (shown in  FIG. 1 ) and a projection  221   b  arranged to be disposed in an opening  232  provided in the conductive sheath  23  (shown in  FIG. 2 ). The projection  221   a  and the projection  221   b  are arranged to fix the location of the dielectric  22  in the conductive sheath  23 . In the present preferred embodiment, the projection  221   a  preferably has a substantially rectangular shape and the projection  221   b  has a substantially semispherical shape. However, each of the projections may have any suitable shape. In this preferred embodiment, the dielectric  22  includes one projection  221   a  and one projection  221   b . However, any suitable number of projections  221   a  and  221   b  may be provided in order to fix the location of the dielectric  22  with respect to the conductive sheath  23 . In addition, any suitable location and arrangement of the projections  221   a  and  221   b  may used. 
     The contact portion  212  of the center conductor  21  is arranged in a trough  222   a  in the frame portion  222  such that the flat surface  212   a  and the curved surface  212   b  of the contact portion  212  is exposed in the trough  222   a  of the frame portion  222 . 
     As best seen in  FIG. 1 , the conductive sheath  23  of the female portion  20  has a substantially square shape, and includes a plurality of resilient arms  233  extending from one side of the intermediate portion  235  and a plurality of terminals  234  extending from corner portions of the opposite side of the intermediate portion  235 . However, the terminals  234  are not required to be disposed at corner portions of the intermediate portion  235 , and instead, may be disposed at any suitable locations of the intermediate portion  235 . The resilient arms  233  are arranged to engage a conductive sheath  43  of the male portion  40 , which is described below. In this preferred embodiment, the terminals  234  of the conductive sheath  23  are arranged to extend through corresponding openings in a circuit board (not shown) and to be soldered therein. However, other attachment structures may be used, such as surface mount technology, solder balls, or crimp solder. In this preferred embodiment, two resilient arms  233  are provided along each of three edges of the intermediate portion  235  and one resilient arm  233  is provided along the fourth edge of the intermediate portion  235 , for example. However, any suitable number and arrangement of resilient arms  233  may be provided along each edge of the intermediate portion  235 . Alternatively, the resilient arms may be provided on the male portion  40 , instead of the female portion  20 . 
     A plurality of the female portions  20  of the contact  10  is typically disposed in a suitable female electrical connector  60 , as shown in  FIGS. 15A to 16D . The female portions  20  of the contact  10  may be used for each of contacts of the female electrical connector  60 , or may be used for only a portion of the contacts of the female electrical connector  60 . 
     As shown in  FIGS. 15A and 15B , each of the female portions  20  are inserted into an opening  61   a  (see  FIG. 16A ) in an upper surface  61  of the female electrical connector  60 , such that the terminals  234  and the tail portion  211  of each of the female portions  20  extend outward from an opening  62   a  provided in the lower surface  62  of the female electrical connector  60 . The arrangement of the female portions  20  in the female electrical connector  60  shown in  FIGS. 15A to 16D  is referred to as a ganged array. As shown in  FIG. 18 , the opening  62   a  has a substantially square geometry which corresponds to the substantially square geometry of the conductive sheath  23 . Alternatively, the female electrical connector  60  may include any suitable number of openings having any suitable arrangement and shape, for example, the female electrical connector  60  may include individual openings through which each of the terminals  234  and the tail portion  211  extends. 
     The female electrical connector  60  includes polarization projections  63   a  on opposite end surfaces  63  of the female electrical connector  60  to ensure a proper orientation of the female electrical connector  60  with the male electrical connector  80  described below. In addition, the female electrical connector  60  includes an alignment projection  62   b  extending from the lower surface  62  thereof. The alignment projection  62   b  is arranged to engage an alignment hole on a circuit board (not shown) or other suitable connection structure. The arrangement and number of the polarization projections  63   a  and the alignment projection  62   b  are not specifically limited, and any suitable arrangement and number may be used. 
       FIGS. 7-12  show a male portion  40  of the contact assembly  10  or a partial portion of the male portion  40  according to a preferred embodiment of the present invention. 
     As seen in  FIGS. 7-12 , the male portion  40  preferably includes a center conductor  41  which extends through a dielectric  42 , and the dielectric  42  is disposed within a conductive sheath  43 . 
     As best seen in  FIG. 12 , the center conductor  41  includes an intermediate portion  413  connecting a tail portion  411  and a contact portion  412 . The contact portion  412  includes, for example, projections  412   a  disposed on opposite sides of the contact portion  412 . The projections  412   a  are provided to engage with a portion of the dielectric  42  to fix the location of the center conductor  41  as shown, for example, in  FIG. 10 . However, any suitable fixing structure may be provided to fix the location of the center conductor  41  in the dielectric  42 . 
     The contact portion  412  of the center conductor  41  is preferably configured to have a thickness that is approximately half of the thickness of the tail portion  411  and the intermediate portion  413  to enable the contact portion  412  to engage with the contact portion  212  of the female portion  20 , such that the combined thickness of the contact portion  412  of the male portion  40  and the contact portion  212  of the female portion  20  is substantially the same as the thicknesses of the tail portions  411  and  211  and of the intermediate portions  413  and  213  of the center conductors  41  and  21 , respectively. With this arrangement, the cross-sectional dimensions of the center conductors  21  and  41  are substantially constant along the entire length of the electrical contact  10 , which results in very good signal integrity performance. In addition, the contact portion  412  preferably has a width that is greater than the width of the contact portion  212  of the center conductor  21  to allow for lateral movement which provides a substantial amount of misalignment tolerance when mating and using the female portion  20  and the male portion  40 . However, the contact portion  412  may have a width that is substantially the same as the width of the contact portion  212  of the center conductor  21 , if a significant amount of misalignment tolerance is not required. 
     The contact portion  412  has a substantially flat surface along substantially the entire length thereof. The substantially flat surface of the center conductor  41  is configured to be engaged with the flat portion  212   a  of the contact portion  212  of the center conductor  21 . In addition, the contact portion  412  preferably includes an end portion  412   b  that extends away from the substantially flat surface of the contact portion  412  to facilitate engagement of the contact portion  412  of the center conductor  41  of the male portion  40  with the contact portion  212  of the center conductor of the male portion  20 . 
     As best seen in  FIGS. 10 and 11 , the center conductor  41  is overmolded with the dielectric  42  such that the center conductor  41  is embedded in the dielectric  42 . Any suitable molding method may be used, for example, injection molding. The dielectric  42  includes a block portion  421  and a support portion  422  which supports the contact portion  412  of the center conductor  41 . Alternatively, the dielectric  42  may be formed with a through-hole extending therethrough, and the center conductor  41  may be inserted into the through-hole and press fit therein. 
     The block portion  421  includes a projection  421   a . The support portion  422  of the dielectric  42  includes a groove  422   a  into which the contact portion  412  of the center conductor  41  is disposed. The groove  422   a  is formed during the overmolding process by the contact portion  412  of the center conductor  41 . The projections  412   a  of the contact portion  412  are preferably embedded in the side surfaces of the groove  422   a  such that the contact portion  412  is fixed in the groove  422   a . In addition, the support portion  422  of the dielectric  42  includes an opening  422   b  extending through the support portion  422  from a bottom surface of the groove  422   a  to an opposed surface of the support portion  422 . The support portion  422  includes another opening  422   c  at an end thereof. The opening  422   c  is arranged to receive the end portion  412   b  of the center conductor  41 . 
     The projection  421   a  of the block portion  421  is arranged to be engaged with an opening  432  of the conductive sheath  43 . The projection  421   a  is arranged to fix the location of the dielectric  42  in the conductive sheath  43 . In this preferred embodiment, the projection  421   a  preferably has a substantially semispherical shape. However, the projection  421   a  may have any suitable shape. In the preferred embodiment, the dielectric  42  includes one projection  421   a . However, any suitable number of projections  421   a  may be provided in order to fix the dielectric  42  with respect to the conductive sheath  43 . In addition, any suitable location and arrangement of projections  421   a  may be used. 
     As best seen in  FIG. 7 , the conductive sheath  43  of the male portion  40  has a substantially square shape and includes a plurality of terminals  434  extending from corner portions of one end of the conductive sheath  43 . However, the terminals  434  are not required to be disposed at corner portions of the conductive sheath  43 , and instead, may be disposed at any suitable locations of the conductive sheath  43 . In this preferred embodiment, the terminals  434  of the conductive sheath  43  are arranged to extend through corresponding openings in a circuit board and be soldered therein. However, other attachment structures may be used, such as surface mount technology, solder balls, or crimp solder. 
     A plurality of male portions  40  of the contact  10  is typically disposed in a suitable male electrical connector  80 , as shown in  FIGS. 17A to 17D . The male portions  40  may be used for each contact of the male electrical connector  80 , or may be used for only a portion of the contacts of the male electrical connector  80 . 
     Each of the male portions  40  are inserted into an opening  81   a  (see  FIG. 16C ) in an upper surface  81  the male electrical connector  80 , such that the terminals  434  and the tail portion  411  of each of the male portions  40  extend outward from an opening  82   a  provided in the lower surface  82  of the male electrical connector  80 , in a similar manner that the female portions  20  are inserted into the opening  61   a  in the upper surface  61  of the female electrical connector  60  as shown in  FIGS. 15A and 15B . The arrangement of the male portions  40  in the male electrical connector  80  shown in  FIGS. 17A to 17D  is referred to as a ganged array. As shown in  FIG. 19 , the opening  82   a  has a substantially square geometry which corresponds to the substantially square geometry of the conductive sheath  43 , respectively. Alternatively, the male electrical connector  80  may include any suitable number of openings having any suitable arrangement and shape, for example, the male electrical connector  80  may include individual openings through which each of the terminals  434  and the tail portion  411  extends. 
     The male electrical connector  80  includes polarization cavities  83   a  on opposite end surfaces  83  of the male electrical connector  80  into which the polarization projections  63   a  of the female electrical connector  60  are disposed when the male electrical connector  80  is engaged with the female electrical connector  60  in the correct orientation. In addition, the male electrical connector  80  includes an alignment projection  82   b  extending from the lower surface  82  thereof. The alignment projection  82   b  is arranged to engage an alignment hole on a circuit board (not shown) or other suitable connection structure. The arrangement and number of the polarization cavities  83   a  and the alignment projection  82   b  are not specifically limited, and any suitable arrangement and number may be used. 
     As shown in  FIGS. 18 and 19 , the array of female portions  20  and the array of male portions  40  of the contacts  10  are arranged in respective female and male electrical connectors  60  and  80  such that the center conductor  211  of each of the array of the female portions  20  can be engaged with a respective center conductor  411  of each of the male portions  40 . In the female and male electrical connectors  60  and  80  shown in  FIGS. 15A to 19 , a single row of female portions  20  and a single row of male portions  40  are provided. However, any suitable number and arrangement of female portions  20  and male portions  40  may be provided, such as a plurality of rows female portions  20  and a plurality of rows of male portions  40  arranged in a matrix, for example. 
     When the female electrical connector  60  is engaged with the male electrical connector  80 , the polarization projections  63   a  are disposed in the polarization cavities  83   a  so as to ensure the correct orientation of the female electrical connector  60  with respect to the male electrical connector  80 . 
     A preferred method of manufacturing the female portion  20  will now be described with reference to  FIGS. 20A to 24B . The male portion  40  is manufactured using substantially the same method as that used to manufacture the female portion  20 , and a description thereof is omitted. 
     As shown in  FIGS. 20A and 20B , a plurality of the center conductors  21  are formed on a strip  100 . Then, as shown in  FIGS. 21A and 21B , the dielectric  22  is formed by overmolding on each of the center conductors  21 . 
     As shown in  FIGS. 22A and 22B , a plurality of conductive sheaths  23  are formed on a strip  101 . Particularly, the plurality of conductive sheaths  23  are formed of a metal plate that is initially stamped into a desired shape while being attached to the strip  101 . The metal plate attached to the strip  101  is then bent and formed into the shape of the plurality of conductive sheaths  23  using progressive dies. Subsequently, the plurality of conductive sheaths  23  are removed from the strip  101 . In the present preferred embodiment, the conductive sheaths  23  are formed by stamping and progressive die processes. However, any suitable processes may be used to form the conductive sheaths  23 . 
     As shown in  FIGS. 23A to 24B , each of the conductive sheaths  23  is mounted on a respective one of the dielectrics  22 , such that the dielectrics  22  are inserted and fixed in a respective one of the conductive sheaths  23 . 
     Once the conductive sheaths  23  are mounted on the dielectrics  22 , each of the completed female contacts  20  is removed from the strip  100 . 
     Although the dielectric  22  is overmolded on the center conductors  21  in the present preferred embodiment, the dielectrics  22  and  42  may be formed with a through-hole therein, and the center conductors  21  and  41  may be press fit into the through-holes provided in the dielectrics  22  and  42 , respectively. Alternatively, each of the dielectrics  22  and  42  may have a clamshell structure in which each of the dielectrics  22  and  42  includes two halves which are configured to be mated together. With the clamshell structure, the two halves of the dielectrics  22  and  42  are mated together with a respective center conductor  21  and  41  disposed therebetween. Furthermore, other suitable methods may be used. 
     Although, in the preferred embodiment shown in shown in  FIGS. 20A to 24B , a plurality of female contacts  20  are manufactured using a strip of conductive material, alternatively, each of the female contacts  20  may be individually formed. 
     As shown in  FIG. 1 , the finally formed conductive sheath  23  includes substantially straight edges that extend substantially in a longitudinal direction of the conductive sheath  23  so as to form a seam  23   a . As seen in  FIG. 9 , the finally formed conductive sheath  43  includes adjacent edges having complementary locking elements  43   a   1  and  43   a   2  forming a seam  43   a . The complementary locking elements  43   a   1  and  43   a   2  along the seam  43   a  are provided to prevent the adjacent edges from separating from one another. In this preferred embodiment, the locking elements preferably have a substantially circular shape. However, the complementary locking elements  43   a   1  and  43   a   2  may have any suitable complementary shapes. Alternatively, the complementary locking elements may be provided along the adjacent edges of seam  23   a  of the conductive sheath  23 , or the complementary locking elements may be omitted completely. 
     As shown in  FIGS. 13 and 14 , the female portion  20  and the male portion  40  of the electrical contact  10  are configured to be mateable with one another. When the female portion  20  and the male portion  40  are mated, the resilient arms  233  of the conductive sheath of the female portion  20  are engaged with an outer surface of the conductive sheath  43  of the male portion  40 . In addition, as seen in  FIG. 14 , when the female portion  20  and the male portion  40  are engaged, the frame portion  222  of the dielectric  22  and the support portion  422  of the dielectric  42  are disposed adjacent to each other, and the contact portion  212  of the center conductor  21  and the contact portion  412  of the center conductor are securely engaged with each other between the frame portion  222  and the support portion  422 . Alternatively, the resilient arms may be provided on the conductive sheath  43  of the male portion  40  and arranged to engage an outer surface of the conductive sheath  23  of the female portion  20 . Alternatively, instead of engaging the outer surface of the conductive sheath, the resilient arms may be configured to engage an inner surface of the conductive sheath. 
     In the electrical contact  10  according to this preferred embodiment of the present invention, since the contact portions  212  and  412  have thicknesses that are substantially half the thickness of the tail portions  211 ,  411 , when the female portion  20  and the male portion  40  of the electrical contact are engaged with one another, the combined cross-sectional dimensions of the engaged contact portions  212  and  412  are substantially the same as the cross-sectional dimensions of the tail portions  211  and  411  and the intermediate portions  213  and  413 . Thus, a consistent geometry of the electrical contact  10  is maintained throughout the entire length of the electrical contact  10 , and signal integrity discontinuities are minimized. 
     Since the substantially square-shaped components of the electrical contact  10  can be manufactured using stamping, molding, and progressive die methods, the electrical contact  10  can be manufactured more quickly and at a reduced cost as compared to the screw machining method that is required to manufacture coaxial contacts. In addition, the manufacturing tolerances required for the electrical contact  10  according to the preferred embodiments of the present invention are substantially less tight as compared to the manufacturing tolerances required for a coaxial contact. 
     The center conductors  21  and  41  and the conductive sheaths  23  and  43  are preferably made of a copper alloy. However, any suitable conductive material may be used. The dielectric is preferably made of plastic. However, any suitable dielectric material may be used. 
     The conductive sheath  23  of the female portion  20  preferably has inner dimensions that are greater than the outer dimensions of the conductive sheath  43  of the male portion such that the misalignment tolerances of the contact  10  can be increased. 
     It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variations which fall within the scope of the appended claims.