Patent Publication Number: US-2023163537-A1

Title: Devices, assemblies, and methods for terminating coaxial radiofrequency ports

Description:
RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 63/281,877, filed Nov. 22, 2021, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The present specification generally relates to radiofrequency termination and, more particularly, to devices, assemblies, and methods for terminating coaxial radiofrequency ports. 
     Radiofrequency (“RF”) signals may be transmitted through cables or lines to various destinations. Within coaxial cable systems, such coaxial lines may be coupled at their ends to equipment boxes, such as signal splitters, amplifiers, etc. These equipment boxes may have several coaxial ports adapted to receive end connectors of coaxial cables. If one or more of such coaxial ports is to be left “open”, such that a connection to further transmit the signal is not secured to the port, then it may be necessary to “terminate” such port with a coaxial terminator. If such a coaxial terminator is omitted, then undesired reflected signals may interfere with the proper transmission of the desired RF signal. Moreover, due to high frequency signals (e.g., 100 GHz) it may be difficult to effectively terminate the signal and prevent interference with existing terminators. 
     Accordingly, a need exists for RF terminators with improved high frequency performance. 
     SUMMARY 
     Additional features and advantages of the present disclosure will be set forth in the detailed description, which follows, and in part will be apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description, which follows the claims, as well as the appended drawings. 
     In a first aspect A1, a coaxial terminator for terminating a coaxial equipment port includes a female connector, an outer housing, at least one support element, a center conductor, cured resin dielectric, and one or more resistive elements. The female connector is disposed within the outer housing, is supported within the outer housing by the at least one support element, and is configured to receive a male pin of the coaxial equipment port. The center conductor has a proximal portion and a distal portion and is coaxially coupled to the female connector at the proximal portion and encircled by cured resin dielectric at the distal portion. The cured resin dielectric is cured in place between the center conductor and the outer housing. The one or more resistive elements are in electrical communication at a first end with the center conductor and at a second end with the inner housing. 
     In a second aspect A2 according to the first aspect A1, a gap is disposed between the one or more resistive elements and the outer housing. In a third aspect according to the second aspect A2, the terminator further comprises a tuning screw threadedly engaged with the outer housing, wherein advancing tuning screw decreases the gap, thereby adjusting the inductance of the coaxial terminator. In a fourth aspect A4 according to any preceding aspect, the coaxial terminator further includes an inner housing encircling the cured resin dielectric, wherein the inner housing is formed of a conductive material and is positioned coaxially within the outer housing such that the inner housing and the outer housing are in electrical communication. In a fifth aspect A5 according to any preceding aspect, the outer housing comprises a first portion and a second portion press-fit within the first portion. In a sixth aspect A6 according to any preceding aspect, the at least one support element comprises dielectric material. In a seventh aspect A7 according to any preceding aspect, the at least one support element includes a first support element and a second support element, and the first support element maintains a coaxial orientation of the female connector relative to the outer housing. In an eight aspect A8 according to the seventh aspect A7, the second support element maintains a coaxial orientation of the female connector relative to the center conductor. In a ninth aspect A9 according to any preceding aspect, the center conductor is press-fit within the female connector. In a tenth aspect A10 according to any preceding aspect, the one or more resistive elements are made of a conductive particulate suspended within the cured resin dielectric. 
     In an eleventh aspect A11, a coaxial terminator for terminating a coaxial equipment port includes a female connector, an outer housing, at least one support element, a center conductor, cured resin dielectric, an inner housing, and one or more resistors. The female connector is disposed within the outer housing, is supported within the outer housing by the at least one support element, and is configured to receive a male pin of the coaxial equipment port. The center conductor has a proximal portion and a distal portion and is coaxially coupled to the female connector at the proximal portion and encircled by cured resin dielectric at the distal portion. The cured resin dielectric is cured in place between the center conductor and the outer housing. The one or more resistors are in electrical communication at a first end with the center conductor and at a second end with the outer housing. 
     In a twelfth aspect A12 according to the eleventh aspect A11, the one or more resistors includes a first resistor and a second resistor, wherein each of the first resistor and the second resistor are in electrical communication with the center conductor and the outer housing such that the first resistor and the second resistor operate in parallel. In a thirteenth aspect A13 according to the twelfth aspect A12, the center conductor defines a longitudinal axis, wherein the first resistor and the second resistor are directionally oriented radially away from the longitudinal axis. In a fourteenth aspect A14 according to any of the eleventh through thirteenth aspects A11-A13, the one or more resistors are soldered at a first end to the center conductor and at a second end to an inner housing, wherein the cured resin dielectric is cured in place within the inner housing. In a fifteenth aspect A15 according to any of the eleventh through thirteenth aspects A11-A13, the coaxial terminator further includes a distal dielectric disposed within an inner housing, wherein the one or more resistors are in electrical communication at the first end to the center conductor and at the second end to the inner housing. In a sixteen aspect A16 according to any of the fourteenth through fifteenth aspects A14-A15, the coaxial terminator further includes a spring extending between the inner housing and the outer housing. In a seventeenth aspect A17 according to any of the eleventh through sixteenth aspects A11-A16, the one or more resistors includes a chip resistor. 
     In an eighteenth aspect A18, a method of assembling a coaxial terminator includes positioning an inner housing about a distal portion of a center conductor, injecting a resin dielectric into the inner housing such that it is encircling the distal portion of the center conductor, curing the resin dielectric about the distal portion of the center conductor, coupling a first resistor at a first end to the center conductor and at a second end to the inner housing such that the first resistor is in electrical communication with the center conductor and the inner housing, and enclosing the center conductor, the resin dielectric, and the first resistor within an outer housing. 
     In a nineteenth aspect A19 according to the eighteenth aspect A18, the method further includes coaxially coupling a proximal portion of the center conductor to a female connector, wherein the female connector is configured to receive a male pin of the coaxial equipment port. 
     In a twentieth aspect A20 according to either the eighteenth aspect A1b or the nineteenth aspect A19, the method further includes coupling a second resistor to the center conductor and the inner housing such that the second resistor is in electrical communication with the center conductor and the inner housing. 
     In a twenty-first aspect A21, a coaxial terminator for terminating a coaxial equipment port includes a center conductor, an outer housing, at least one support element, and a resistive element. The center conductor has a proximal portion and a distal portion, and the proximal portion includes a female connector. The at least one support element supports the center conductor axially within the outer housing. The resistive element electrically couples the center conductor to the outer housing. The resistive element comprises a cured resin dielectric and a conductive particulate suspended within the cured resin dielectric. 
     In a twenty-second aspect A22 according to the twenty-first aspect A21, the outer housing and the center conductor define an injection passage extending therethrough, wherein the resistive element is disposed within the injection passage. In a twenty-third aspect A23 according to the twenty-first or twenty-second aspect A21-A22, the resistive element encircles a portion of the center conductor. In a twenty-fourth aspect A24 according to any of the twenty-first through twenty-third aspects A21-A23, the resistive element is injected into a space abutting the center conductor and cured in place. In a twenty-fifth aspect A25 according to any of the twenty-first through twenty-fourth aspects A21-A24 the resistive element has a resistance of 50 ohms. 
     These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which: 
         FIG.  1    schematically illustrates a perspective view of a coaxial RF terminator, according to one or more embodiments shown and described herein; 
         FIG.  2    schematically illustrates a cross-sectional view of the coaxial RF terminator of  FIG.  1   , according to one or more embodiments shown and described herein; 
         FIG.  3    schematically illustrates a perspective view of internal components of the terminator of  FIG.  1   , according to one or more embodiments shown and described herein; 
         FIG.  4 A  schematically illustrates a perspective rear view of a resistor assembly of the terminator of  FIG.  1   , according to one or more embodiments shown and described herein; 
         FIG.  4 B  schematically illustrates a perspective front view of the resistor assembly of  FIG.  4 A , according to one or more embodiments shown and described herein; 
         FIG.  5    schematically illustrates a perspective rear view of a resistor assembly of a coaxial RF terminator, according to one or more embodiments shown and described herein; 
         FIG.  6    schematically illustrates a cross-sectional view of a coaxial RF terminator including the resistor assembly of  FIG.  5   , according to one or more embodiments shown and described herein; 
         FIG.  7    schematically illustrates a cross-sectional view of a coaxial RF terminator, according to one or more embodiments shown and described herein; 
         FIG.  8    schematically illustrates a cross-sectional view of a coaxial RF terminator, according to one or more embodiments shown and described herein; 
         FIG.  9    schematically illustrates a cross-sectional view of a coaxial RF terminator, according to one or more embodiments shown and described herein; 
         FIG.  10    schematically illustrates a cross-sectional view of a coaxial RF terminator, according to one or more embodiments shown and described herein; and 
         FIG.  11    schematically illustrates a cross-sectional view of a coaxial RF terminator, according to one or more embodiments shown and described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments of devices, assemblies, and methods, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. 
     Referring generally to  FIGS.  1 - 2   , a coaxial RF terminator is schematically depicted. The RF terminator may generally include a female connector, an outer housing, at least one support element, a center conductor, a cured resin dielectric, and one or more resistive elements. The female connector is configured to receive a male pin of a coaxial equipment port (not shown) and is disposed within the outer housing and is supported within the outer housing by the at least one support element. The center conductor may include a proximal portion and a distal portion and may be coaxially coupled to the female connector at the proximal portion and encircled by the cured resin dielectric at the distal portion. The cured resin dielectric is cured in place between the center conductor and the outer housing. The one or more resistive elements may be mounted to the center conductor and may be in electrical communication at a first end with the center conductor and at a second end with the outer housing. In this way, an RF signal received from the male pin may travel through the female connector, through the center conductor, through the resistive element, and then to the outer housing, which may be grounded, such that the RF signal is terminated with minimal reflection. As noted above, the cured dielectric resin may be cured in place thereby filling substantially all of the voids between the center conductor and the outer housing or any intervening components, thus providing improved signal isolation and termination. This and other embodiments will be described in greater detail below. 
     Directional terms as used herein—for example up, down, right, left, front, back, top, bottom—are made only with reference to the figures as drawn and are not intended to imply absolute orientation unless otherwise specified. The terms proximal and distal are used herein to reference a direction toward a coaxial equipment port and away from a coaxial equipment port, respectively. 
     Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any device or assembly claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an device or assembly is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation; and the number or type of embodiments described in the specification. 
     As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise. 
     Referring now to  FIGS.  1  and  2   , an embodiment of an RF terminator  100  is schematically depicted. As described herein, a terminator may be used to terminate an RF (such as microwave) signal. For example, coaxial transmission mediums for conveying information at microwave frequencies may be characterized by their relatively small size, which is not only a consequence of the operation frequency range, but may also be attributable to application and environments of the systems in which such communications are employed. For example, such systems may be found in sophisticated radars with multiple ports in which size and/or weight restrictions may result in a desire for reductions in size and/or weight. In multiple-port radars, any unused ports may need an RF terminator to prevent a transmission line open circuit, outside, signal reflection, and/or outside or spurious signal ingress, which could otherwise interfere with the system. The RF terminator  100  generally includes an outer housing  10 , a female connector  40 , and a resistor assembly  20  (depicted in  FIG.  2   ). The RF terminator  100  generally defines a coaxial connection axis A along which RF signals are transmitted and which may be used to spatially describe various components of the RF terminator  100 . It is noted that a greater or fewer of components may be included within the RF terminator  100  without departing from the scope of the present disclosure. 
     The outer housing  10  generally defines the exterior of the RF terminator  100  and may include a port end  14  for receiving an RF transmission line (e.g., a male connector), which is coaxial with the coaxial connection axis A. In some embodiments, the outer housing  10  may form a single structure or in other embodiments, the outer housing  10  may generally include a first portion  11  and a second portion  12  couplable to the first portion  11 . For example, the first portion  11  and second portion  12  may be coupled with a press-fit connection, threaded connection, adhesive, weld, brazing, or any other suitable connection. For example, and as illustrated in  FIG.  2   , the second portion  12  may be received within the first portion  11  (or vice versa) to couple the first portion  11  to the second portion  12 . The outer housing  10  may define an outer housing volume  13 , which houses various internal components of the RF terminator  100 , described in greater detail below. The outer housing  10  may be formed of one or more conductive materials (e.g., copper, gold, silver, platinum, nickel, or the like). The outer housing  10  may be formed via casting, additive manufacturing, etc. In some embodiments, the outer housing  10  may be formed of a base material (conductive or not) coated with one or more conductive coatings (e.g., copper, gold, silver, platinum, nickel, or the like). 
     In embodiments the port end  14  may form part of the first portion  11  of the housing and may be positioned proximally the second portion  12 . The port end  14  may generally define a port  15  that may include a plurality of radial slits  16  as depicted which may provide radial flexibility to the port  15 , thereby providing improved connection to a port of an equipment box (not depicted). The plurality of radial slits  16  may include any number such as two or more slits, four or more slits, etc. 
     In embodiments, one or more gripping features  17  may be formed on an outer surface of the outer housing  10 . The one or more gripping features  17  (e.g., ribs, edges, etc.), may provide improved assembly and/or handling of the outer housing  10 . The one or more gripping features  17  may be formed on the first portion  11  (as depicted), the second portion  12 , or both. 
       FIG.  2    generally depicts a cross-sectional view of the RF terminator  100  taken along line  2 - 2  of  FIG.  1   , inside of the outer housing  10 , which may house the female connector  40  and the resistor assembly  20 . The female connector  40  may be positioned within the outer housing  10 . For example, the female connector  40  may extend concentrically within the outer housing  10  along the coaxial connection axis A. In embodiments, the female connector  40  defines a first female connecting end  42   a  and a second female connecting end  42   b  opposite the first female connecting end  42   a . However, other configurations are contemplated and possible. In the illustrated embodiment, the first female connecting end  42   a  is pointed concentrically within the port  15  of the port end  14  for receiving a male connector of an equipment port (not shown). 
     In embodiments, the female connector  40  may be formed from a conductive material such as, but not limited to, copper, gold, silver, platinum, nickel, etc. In embodiments, the female connector  40  may be a solid metal material, which may be formed via casting, additive manufacturing, etc. In some embodiments, the female connector  40  may be a metal material and have one or more conductive coatings applied thereto (e.g., copper, gold, silver, platinum, nickel, or the like). 
     The female connector  40  may have a female connector hub  44  from which the first female connecting end  42   a  and the second female connecting end  42   b  extend. The female connector hub  44  may define a recess  47  for receiving a support element (e.g., support element  30 ), as will be described in greater detail below. Each of the first female connecting end  42   a  and the second female connecting end  42   b  may define two or more fingers  48   a ,  48   b . Separation between the two or more fingers  48   a ,  48   b , may provide radial flexibility to the first female connecting end  42   a  and the second female connecting end  42   b  to allow the first female connecting end  42   a  and the second female connecting end  42   b  to clamp onto a received male mating feature. 
     As noted above, also positioned within the outer housing  10  is the resistor assembly  20 . The resistor assembly  20  may be positioned distal to the port end  14  of the outer housing  10  and the female connector  40 . In embodiments, the resistor assembly  20  may be electrically coupled to the second female connecting end  42   b , as shown. In general, the resistor assembly  20  may include an inner housing  22 , center conductor  25 , one or more resistive elements (such as resistive element  21 , depicted in  FIG.  3   ), and cured resin dielectric  23 . Alternatively, a dielectric material, such as PCB, may be shaped prior to assembly and assembled in place. It is noted that a greater or fewer of components may be included within the resistor assembly  20  without departing from the scope of the present disclosure. 
     In embodiments, the inner housing  22  may be formed from a conductive material such as, but not limited to, copper, gold, silver, platinum, nickel, etc. The inner housing  22  may be a solid metal material, which may be formed via casting, additive manufacturing, etc. In some embodiments, the inner housing  22  may be a metal material and have one or more platings applied thereto (e.g., gold, copper, etc.). Still referring to  FIG.  2   , the inner housing  22  may have an outer wall  22   a  and an inner wall  22   b . As will be described in more detail herein, the outer wall  22   a  of inner housing  22  may be positioned within the second portion  12  of the outer housing  10 . Accordingly, the outer wall  22   a  of inner housing  22  may have a geometry corresponding to that of the second portion  12  of the outer housing  10 . As depicted, the outer wall  22   a  of inner housing  22  may have an L-shaped radial cross-section; however, other shapes are contemplated and possible. The inner wall  22   b  of inner housing  22  may encircle center conductor  25  and may be contacted therewith. As depicted, the inner wall  22   b  of inner housing  22  may be substantially cylindrical, though other shapes are contemplated and possible. In embodiments, the inner wall  22   b  and the outer wall  22   a  may be electrically isolated from one another such that they are not in electrical communication. For example, the inner wall  22   b  and the outer wall  22   a  may be insulated from one another via the cured resin dielectric  23 , which is described in greater detail below. 
     The center conductor  25  may be positioned within the inner housing  22  along the central coaxial connection axis A. In embodiments, the center conductor  25  may be formed from a conductive material such as, but not limited to, copper, gold, silver, platinum, nickel, etc. In embodiments, the center conductor  25  may be a solid metal material, which may be formed via casting, additive manufacturing, etc. In some embodiments, the center conductor  25  may be a metal material and have one or more platings applied thereto (e.g., gold, copper, etc.). The center conductor  25  may define a proximal end  25   a  and distal end  25   c , and a central portion  25   b  extending therebetween. The center conductor  25  has a substantially round axial shape, though other shapes are contemplated and possible. The proximal end  25   a  and the distal end  25   c  may have an axial shape with a smaller diameter than the central portion  25   b . In particular, proximal end  25   a  may have a diameter small enough to be received within a female connecting end such as the second female connecting end  42   b  of female connector  40 . That is, the proximal end  25   a  may define a male connector of the center conductor  25 , which is inserted into the second female connecting end  42   b  of the female connector  40 , as depicted. 
     Referring again to  FIG.  3   , the female connector  40  is coupled to the center conductor  25  of the resistor assembly  20 . In particular, the female connector  40  is coaxially coupled to a center conductor  25  of the resistor assembly  20  along the coaxial connection axis A such that the female connector  40  and the center conductor  25  are in electrical communication. In the present embodiment, the female connector  40  is coaxially coupled with a press-fit or interference-fit connection to the center conductor  25 . However, a threaded connection or any other appropriate coaxial connection may also be used. In the present embodiment, the female connector  40  has a female geometry at its distal end, and the center conductor  25  has a male geometry at its proximal end such that the male geometry of the center conductor  25  may be received within the female geometry of the female connector  40 . However, the respective geometries may be switched. It is noted that in the embodiment, the center conductor  25  and the female connector  40  are illustrated as separate components coupled to one another. In other embodiments, the center conductor  25  and the female connector  40  may be integral with one another. 
     Referring again to  FIG.  2   , the female connector  40  may be supported within the outer housing  10  by at least one support element, such as a support element  30 . The support element  30  may encircle a portion of or an entire radial perimeter of the female connector  40 , such as within the recess  47  at the female connector hub  44 , and extend radially outward to abut an inner wall of the outer housing  10 . By placing the support element  30  within the recess  47 , a position of the support element  30  along the female connector  40  may be fixed. In this way, the support element  30  helps maintain the female connector  40  in a coaxial or nearly coaxial orientation relative to the outer housing  10 . Accordingly, both the outer housing  10  and the female connector  40  may be substantially centered about the coaxial connection axis A. The support element  30  may be made of an electrically insulating material such as dielectric material to prevent electrical communication through the support element  30 . In particular, the support element  30  may be made of printed circuit board (PCB) material (e.g., epoxy, polyimide, Teflon, etc.). In some embodiments and as will be described in greater detail below, one or more support elements  30  may be used to support the female connector  40  within the outer housing  10 , such as two or more support elements. 
     Referring now to  FIGS.  4 A and  4 B , the resistor assembly  20  may have one or more resistive elements, such as a resistive element  21 . The resistive element  21  may be a resistor and/or resistive material having a first terminal end  24  and a second terminal end  26  opposite the first terminal end  24 . The resistive element  21  may include any commercially available resistor, such as a thick-film chip resistor, commercially available from any number of sources including Dale Electronics of Norfolk, Nebr. or Amitron of North Andover, Mass. Resistor  311 , a plate resistor, a coated ceramic block, or the like. The resistive element  21  may also be a resistive material such as a conductive particulate that may be suspended in a material. For example, the resistive material could be a resin and/or epoxy material such as an epoxy phenol novolac based resin. Alternatively, the resistive material could be a ruthenium, iridium, and rhenium oxide based material. The resistive element  21  may have a characteristic resistance of 25-100 ohms, such as a 50-ohm resistor. For example, the resistance may be based on the frequency of the signal being terminated. 
     As depicted, the resistive element  21  may be coupled to the center conductor  25  at the second terminal end  26  such that the resistive element  21  and the center conductor  25  are in electrical communication. This may be accomplished with a solder connection or any appropriate connection that allows electrical communication. The resistive element  21  is similarly coupled to the inner housing  22  at the first terminal end  24  such that the resistive element  21  and the inner housing  22  are in electrical communication. In this way, an electrical signal may travel from the center conductor  25  though the resistive element  21  and to the inner housing  22 . The resistive element  21  may be in a distal position relative to the center conductor  25  and the inner housing  22  and may be oriented in a radial direction so as to extend away from the coaxial connection axis A. For example, the resistive element  21  may either contact the coaxial connection axis A and extend directly therefrom or be radially offset from the coaxial connection axis A. If the resistive element  21  is radially offset from the coaxial connection axis A such that the resistive element  21  is not contacted to the center conductor  25 , the space between the resistive element  21  and the center conductor  25  may be filled with solder material or another conductive material to maintain electrical communication between the resistive element  21  and the center conductor  25 . 
     Still referring to  FIG.  2   , as noted above, the resistor assembly  20  may further include the cured resin dielectric  23 . The cured resin dielectric  23  may be positioned distally of the first portion  11  of outer housing  10 . The cured resin dielectric  23  may encircle a portion of center conductor  25  such as at distal end  25   c . As depicted, cured resin dielectric  23  may extend distally past the distal end  25   c  of center conductor  25 . However, as will be described in more detail herein, cured resin dielectric  23  may not extend distally past the distal end  25   c  of center conductor  25 . As depicted, cured resin dielectric  23  has a shape substantially similar to a hollow cylinder. However, other geometries are contemplated and possible. 
     Many types of cured resin dielectric may be used to form the cured resin dielectric  23 . In particular, the cured resin dielectric  23  may be an epoxy resin, a urethane resin, a silicone resin, or the like, such as an epoxy phenol novolac based resin. In some embodiments, the cured resin dielectric  23  may have a 24-hour pot life with an imidazole catalyst, which may be thermally cured in place. In some embodiments, the cured resin dielectric  23  may have a relatively low thermal curing temperature, such as between about 120° C. and 170° C., such as about 150° C. By utilizing lower curing temperatures, surface quality (e.g., plating) on various components of the resistor assembly  20  may be preserved. In embodiments, the cured resin dielectric  23  may be injected into the inner housing  22  as a liquid such that it fills space between the inner wall  22   b  and the outer wall  22   a . In some embodiments, the inner wall  22   b  may be coupled to the center conductor  25  (e.g., via welding, brazing, or the like) or the inner wall  22   b  may be integral therewith. Using a jig or structure to hold the center conductor  25  and/or the inner wall  22   b  relative to the outer wall  22   a , the resin dielectric may be cured in situ. In this way, the resin dielectric may be shaped to completely fill the space between the outer wall  22   a  and the inner wall  22   b  (and/or the center conductor  25 ). In some embodiments, there may not be an inner wall  22   b , instead the dielectric material may be injected directly between the outer wall  22   a  of the inner housing  22  and the center conductor  25  and cured in place, thereby providing improved contact between the dielectric resin and the center conductor  25  and the dielectric resin and the inner housing  22 . By curing the dielectric resin in place, air pockets may be eliminated which may otherwise reduce terminator performance. Moreover, by using a dielectric resin, which may be injected and cured in place, various geometries of the inner housing  22  and center conductor  25  may be used. Alternatively, a dielectric material, such as PCB, may be shaped prior to assembly and assembled in place. 
     The cured resin dielectric  23  is configured to maintain a coaxial orientation between the center conductor  25  and the outer wall  22   a  of the inner housing  22  without allowing physical contact (thereby preventing direct electrical signals) between the center conductor  25  and/or the inner wall  22   b  of the inner housing  22  with the outer wall  22   a  of the inner housing  22 . In this way, an electrical signal traveling through the center conductor  25  will travel through the resistive element  21  before reaching the inner housing  22 . 
     Referring back to  FIG.  2   , the resistor assembly  20  may be positioned within the outer housing  10  such that the inner housing  22  (such as the outer wall  22   a ) abuts, and is in electrical communication with, the second portion  12  of the outer housing  10 . The resistor assembly  20  may be further positioned such that a gap  50  is formed distally of the resistive element  21  and between the resistive element  21  and the second portion  12  of the outer housing  10 . The electrical communication with the outer housing  10  all an RF signal to travel from the resistive element  21 , through the outer wall  22   a  of the inner housing  22 , and to the outer housing  10 . As noted above, the outer housing  10  may be operable to ground the circuit of RF terminator  100 . As will be appreciated by those skilled in the art, the impedance of the circuit of RF terminator  100  may controlled in part by the volume of air defined by gap  50 . Accordingly, the width of the gap  50  along the coaxial connection axis A, may be tuned to a specific desired impedance. Additional embodiments as provided herein may provide an adjustable impedance structure. 
     Methods of assembling an RF terminator  100  are also disclosed herein. It is noted that methods may include a greater or fewer number of steps, in any order, without departing from the scope of the present disclosure. For example, the method includes positioning the center conductor  25  coaxially relative to the inner housing  22  as illustrated in  FIGS.  4 A and  4 B . The method further includes injecting a resin dielectric into the inner housing  22  such that it encircles a portion of the center conductor  25  and curing the resin dielectric such that it forms a cured resin dielectric  23 . As illustrated in  FIGS.  4 A and  4 B , cured resin dielectric  23  encircles a portion of the center conductor  25  and completely fills the space between the inner housing  22  and the center conductor  25  and/or the space between the outer wall  22   a  and the inner wall  22   b  of the inner housing  22 . The method further includes soldering the resistive element  21  to the center conductor  25  and the inner housing  22  at terminal ends  26  and  24 , respectively. The method may further include positioning the support element  30  about the female connector  40 . As shown in  FIG.  3   , support element  30  encircles the female connector  40  at the female connector hub  44 . The method may further include coupling the second female connecting end  42   b  of female connector  40  to the proximal end  25   a  of center conductor  25 . In some embodiments, the method further includes enclosing the resulting subassembly of internal components within the outer housing  10  by coupling the first portion  11  of the outer housing  10  to the second portion  12  of the outer housing  10 . 
     As will be appreciated by those skilled in the art, the assembly need not occur in this particular order. For example, positioning the support element  30  about the female connector  40  may occur before or after coupling the second female connecting end  42   b  of female connector  40  to the proximal end  25   a  of center conductor  25 . In other embodiments, and as noted above, the female connector  40  may be integrated with the center conductor  25  so as to be a single part. 
     Referring now to  FIG.  5   , another embodiment of a resistor assembly  200  is schematically depicted. The resistor assembly  200  includes many of the same components as described above, accordingly the above description applies to the present embodiment, unless otherwise noted or apparent, and will not be repeated. 
     The resistor assembly  200  generally includes a center conductor  250 , an inner housing  220 , a cured resin dielectric  230 , and resistive elements  210  and  211 . That is, the present embodiment includes at least two resistive elements  210  and  211 . In embodiments, the resistive elements  210  and  211  may be arranged in circumferential positions about the coaxial connection axis A. Accordingly, the resistive elements  210  and  211  may be directionally oriented radially away from the coaxial connection axis A. The resistive elements  210  and  211  may be arranged in-line with one another as shown. However, other positions are contemplated and possible. In embodiments, the resistive elements  210  and  211  may be arranged in electrical communication with the center conductor  250  and the inner housing  220  so that the resistive elements  210  and  211  operate in parallel, as depicted. This may be beneficial in some applications as two resistive elements operating in parallel may accommodate a greater maximum throughput power as compared to an equivalent single resistive element. For example, two 100-ohm resistors operating in parallel may accommodate a greater maximum throughput power as compared to one 50-ohm resistor operating alone. However, we note the serial arrangements are also contemplated and possible. 
     For example, in other embodiments, there may be three or more resistive elements. In such an embodiment, the resistive elements may be arranged in equally or unequally spaced circumferential positions about the coaxial connection axis A such that the three or more resistive elements operate in parallel. However, other configurations are contemplated and possible. 
     Referring now to  FIG.  6   , a cross-sectional view of an embodiment of a RF terminator  300  is schematically depicted. It is noted that the RF terminator  300  is substantially similar to the above-described RF terminator  100 . Accordingly, description of like components may apply equally to the present embodiment unless otherwise noted or apparent. For the example, the RF terminator  300  generally includes an outer housing  310 , which may include a first portion  311  and a second portion  312 , a female connector  340 , a support element  330 , and a resistor assembly  320 , such as described above. The resistor assembly  320  may include a center conductor  325 , a resistive element  326 , an inner housing  322 , and cured resin dielectric  323  (and/or PCB material), such as described above. The RF terminator  300  may further include a gap  350  located distally of the resistor assembly  320  and disposed between the resistor assembly  320  and the outer housing  310 . 
     However, in the present embodiment, the second portion  312  has a threaded distal end, having an internal thread aperture  361  that is configured to receive a tuning screw  360 . Accordingly, the tuning screw  360  may be distally located relative to the resistive element  326 , thereby increasing or decreasing a size of the gap  350 . As will be appreciated by those skilled in the art and as noted above, the impedance of the circuit of RF terminator  300  may be controlled in part by the volume of air defined by the gap  350 . This volume can be varied by distally retracting or proximally advancing the tuning screw  360 . As described hereinabove, the tuning screw  360  may be threadedly engaged with the second portion  312  of the outer housing  310  and can retract or advance accordingly. The gap  350  will increase in volume when the tuning screw  360  is distally retracted and will decrease in volume when the tuning screw  360  is proximally advanced. Accordingly, by advancing or retracting the tuning screw  360 , the impedance of the circuit of RF terminator  300  can be adjusted and customized for a particular application. 
     Referring now to  FIG.  7   , a cross-sectional view of another embodiment of RF terminator  400  is schematically depicted. It is noted that the RF terminator  400  is substantially similar to the above-described RF terminator  300  and  100 . Accordingly, description of like components may apply equally to the present embodiment unless otherwise noted or apparent. For the example, the RF terminator  400  generally includes an outer housing  410 , which may include a first portion  411  and a second portion  412 , a female connector  440 , a support element  430 , a resistor assembly  420 , and a tuning screw  460  with a thread aperture  461 . The resistor assembly  420  may include a center conductor  425 , a resistive element  426 , an inner housing  422 , and cured resin dielectric  423  (and/or PCB material), such as described above. The RF terminator  400  may further include a gap  450  located distally of the resistor assembly  420  and disposed between the resistor assembly  420  and the outer housing  410 . 
     In the present embodiment, the coaxial connection between the center conductor  425  and female connector  440  is additionally supported by a second support element  431 . The second support element  431  encircles a portion of the center conductor  425  and a portion of the female connector  440  to help maintain the coaxial arrangement of the female connector  440  relative to the center conductor  425 . The second support element  431  also extends radially to abut an inner surface of the outer housing  410 . In this way, the second support element  431  also helps maintain the coaxial arrangement of the center conductor  425  and the female connector  440  relative to the outer housing  410 . Accordingly, the center conductor  425 , the female connector  440 , and the outer housing  410  may each be substantially centered about the coaxial connection axis A. The second support element  431  may be made of dielectric material (e.g., PCB, epoxy, polyimide, Teflon, polyethylene, polyetherimide, acetal, and polyamide-imide, etc.). 
     In the present embodiment, the cured resin dielectric  423  is proximally recessed relative to the distal ends of inner housing  422  and center conductor  425 . In this way, the resistive element  426  may not contact the cured resin dielectric  423  but may instead contact the center conductor  425  and the inner housing  422  and bridge over the cured resin dielectric  423 . 
     In the present embodiment, the inner housing  422  may not have an inner wall separated from an outer wall as described above. Instead, the inner housing  422  may only include the outer wall  422   a  may define a groove  424  formed within a radially inner surface of the inner housing  422 . In this way, the dielectric resin may fill the groove  424  when injected in a liquid state. The resin may then be cured in place. Accordingly, the cured resin dielectric  423 , when cured, may substantially fill the groove  424 . This may facilitate maintaining the location of the cured resin dielectric  423  relative to the inner housing  422 . 
     Referring now to  FIG.  8   , a cross-sectional view of another embodiment of RF terminator  500  is schematically depicted. It is noted that the RF terminator  500  is substantially similar to the above-described RF terminator  400 ,  300 , and/or  100 . Accordingly, description of like components may apply equally to the present embodiment unless otherwise noted or apparent. For example, RF terminator  500  generally includes an outer housing  510  including a first portion  511  and second portion  512 , support elements  530  and  531 , center conductor  525 , and resistive element  526 . However, in the present embodiment, there is not inner housing. Other differences are outlined below. 
     In particular, in the present embodiment, the center conductor  525  has an integrated female connector as opposed to having a separated center conductor and female connector. For example, the center conductor  525  extends concentrically along the coaxial connection axis A and is supported therein via the support elements  530  and  531 . In the present embodiment, the center conductor  525  has a female connecting end  540 . The female connecting end  540  may be substantially similar to the first female connecting end  42   a  of female connector  40  of RF terminator  100 , shown in  FIG.  2    and described above. In this way, RF terminator  500  need not include a female connector distinct from the center conductor  525 . However, it is contemplated that, in other embodiments, a female connector distinct from the center conductor  525  may be included. 
     In the present embodiment, RF terminator  500  further includes a resistive element  526  positioned distally of support element  531 . As depicted, the resistive element  526  may encircle and abut a portion of the center conductor  525 , such as around a distal end  541  of the center conductor  525 . For example, the resistive element  526  may be positioned within and abutting the first portion  511  of outer housing  510 . As depicted, the resistive element  526  may have a shape similar to a hollow cylinder; however other shapes are contemplated and possible. The resistive element  526  may include an electrically resistive material. In particular, the resistive element  526  may include a conductive particulate  527 . The conductive particulate  527  may be any conductive material such as copper, gold, silver, platinum, nickel, or the like, The conductive particulate  527  may be suspended within a supporting material such as a cured resin dielectric  523  so as to form a shape that abuts both the center conductor  525  and outer housing  510 . When the conductive particulate  527  is suspended within a supporting material, such as a cured resin dielectric  523 , the resulting resistive element  526  may be electrically conductive with a predetermined resistance. This predetermined resistance may be a resistance between 25-100 ohms, such as 50 ohms. In this way, an RF signal may travel from the center conductor  525 , through the conductive particulate  527 , which may be suspended in a cured resin dielectric  523 , and to the outer housing  510 . In embodiments, the cured resin dielectric  523  may be epoxy resin, urethane resin, silicone resin, and the like. In embodiments, the resin dielectric material may be injected into a space between the center conductor  525  and the outer housing  10  (such as the first portion  11  of the outer housing  10 ) and cured in place. Accordingly, the resistive element  526  may support the center conductor  525  within the outer housing  510  and provide a resistance along the electrical pathway, to provide for signal termination. 
     Referring now to  FIG.  9   , a cross-sectional view of another embodiment of RF terminator  600  is schematically depicted. It is noted that the RF terminator  600  is substantially similar to the above-described RF terminator  500 ,  400 ,  300 , and/or  100 . Accordingly, description of like components may apply equally to the present embodiment unless otherwise noted or apparent. For example, RF terminator  600  generally includes an outer housing  610 , center conductor  625 , and support elements  630  and  631 , such as described above. The center conductor  625  may include a female connector  640 , such as described above. 
     In the present embodiment, RF terminator  600  includes the cured resin dielectric  624  that is positioned within the outer housing  610  and distal relative to the support element  631 . The cured resin dielectric  624  may encircle a portion of center conductor  625  such as a distal end of center conductor  625  as shown. The cured resin dielectric  624  may be made out of an electrically resistive material. 
     Each of the cured resin dielectric  624 , the center conductor  525 , and the outer housing  610  may include a through-hole or passageway. The respective though-holes may be substantially aligned such that they form a continuous injection passage  650  extending through the cured resin dielectric  624 , the center conductor  525 , and the outer housing  610 , as shown. The continuous injection passage  650  may substantially cylindrical, though other shapes are contemplated and possible. 
     The continuous injection passage  650  may be formed by a variety of methods. In particular, the continuous injection passage  650  may be formed by assembling the cured resin dielectric  624 , the center conductor  525 , and the outer housing  610  and machining or boring the continuous injection passage  650  therethrough. Alternatively, the continuous injection passage  650  may be formed by assembling the cured resin dielectric  624 , the center conductor  525 , and the outer housing  610 , each having a preformed through-hole, thereby creating the continuous injection passage  650 . 
     Resistive element  626  may be disposed within continuous injection passage  650 . For example, the resistive element  626  may include a conductive particulate  627  suspended in a cured resin dielectric  623  such as described above. The conductive particulate  627  suspended in a liquid form of the resin dielectric may be injected into continuous injection passage  650  and cured in place. In this way, an RF signal may travel from the center conductor  625 , through the resistive element  626  and to the outer housing  510   
     Referring now to  FIG.  10   , a cross-sectional view of yet another embodiment of RF terminator  700  is schematically depicted. It is noted that the RF terminator  700  is substantially similar to the above-described RF terminator  600 ,  500 ,  400 ,  300 , and  100 . Accordingly, description of like components may apply equally to the present embodiment unless otherwise noted or apparent. For the example, the RF terminator  700  generally includes an outer housing  710  (which may include a first portion  711  and a second portion  712 ), a support element  730 , a female connector  740 , a center conductor  725 , cured resin dielectric  723 , inner housing  722 , and a resistive element  726 , such as described above. 
     In the depicted embodiment, the first portion  711  and the second portion  712  are not press fit together, instead, the first portion  711  abuts the second portion  712  such that the first portion  711  and second portion  712  may be joined with a butt weld, for example. In other embodiments, first portion  711  and second portion  712  may be joined with a different weld, press-fit connection, threaded connection, adhesive, or any other suitable connection. 
     Within the outer housing  710  and disposed between the support element  730  and the cured resin dielectric  723 , the RF terminator  700  may include a metallic support element  780 . The metallic support element  780  may define an inner wall  780   a  and an outer wall  780   b  that is positioned radially outward of inner wall  780   a . The inner wall  780   a  may be offset from and coaxial with coaxial connection axis A such that the metallic support element  780  may surround a portion of the center conductor  725  and/or a portion of female connector  740  without contacting the center conductor  725  and/or female connector  740 . Outer wall  780   b  may be radially outward of inner wall  780   a  such that it contacts the outer housing  710 . The support element  730  may contact the cured resin dielectric  723  such that it supports the longitudinal position of the cured resin dielectric  723  within the outer housing  710 . 
     Positioned distally of resistive element  726 , the RF terminator  700  may include a spring support  728  and a spring support housing  727 . The spring support housing  727  may be positioned within the outer housing  710 . As depicted, the spring support housing  727  may be substantially cylindrical, though other shapes are contemplated and possible. The spring support housing  727  may be made from conductive material (e.g., copper, gold, silver, platinum, nickel, or the like). 
     The spring support  728  may be housed within the spring support housing  727 . The spring support  728  may be shaped similar to a hollow cylinder, though other shapes are contemplated and possible. In particular, in embodiments, the spring support  728  may not be hollow at its center. The spring support  728  may be made from an electrically insulating material such as cured resin dielectric. The spring support  728  may instead be made from PCB material (e.g., epoxy, polyimide, Teflon, etc.) that is not cured in place. 
     Within the outer housing  710  and distal of the spring support  728 , the RF terminator  700  may include a spring  770  formed from any appropriate spring material. In particular, the spring  770  may be made from a spring-form, metallic material such as spring steel. The length of the spring  770  may extend from the spring support  728  to the outer housing  710  in a distal direction such that it contacts both the spring support  728  and the outer housing  710 . The diameter of the spring  770  may be sized such that the spring  770  contacts the outer housing  710  in the radial direction. 
     The resistive element  726  may be coupled at a first end to the center conductor  725 , such as described above. The resistive element  726  may be coupled at a second end to the spring support housing  727  such that the resistive element  726  and the spring support housing  727  are in electrical communication. The spring support housing  727  may be in electrical communication with the spring  770 , which may in turn be in electrical communication with the outer housing  710 . The electrical communication between the spring  770  and the outer housing  710  may operate to ground the circuit of the RF terminator  700 . Additionally, the spring  770  may operate to retain the spring support  728  in place within the RF terminator  700 . 
     Referring now to  FIG.  11   , a cross-sectional view of another embodiment of RF terminator  800  is schematically depicted. It is noted that the RF terminator  800  is substantially similar to the above-described RF terminator  700 ,  600 ,  500 ,  400 ,  300 , and/or  100 . Accordingly, description of like components may apply equally to the present embodiment unless otherwise noted or apparent. For the example, the RF terminator  800  generally includes an outer housing  810 , which may include a first portion  811  and a second portion  812 , a center conductor  825 , a female connector  840 , a support element  830 , a metallic support element  880 , a cured resin dielectric  823 , an inner housing  822 , and a resistive element  826 , such as described above. 
     Within outer housing  810  and distal of the cured resin dielectric  823 , RF terminator  800  may further include a domed spring  870 . The domed spring  870  may be formed of a spring-form, metallic material such as spring steel. As depicted, the domed spring  870  may be substantially dome shaped such that it contacts an outer radius of the inner housing  822  at its proximal end  870   a  and contacts a radially centered portion of the outer housing  810  at its distal end  870   b . Accordingly, the resistive element  826  is disposed within the dome shape of domed spring  870  and is not in contact with the domed spring  870 . 
     It is noted that features of each of the above embodiments may be incorporated with one another, though described separately, without departing from the scope of the present disclosure. For example, one or more features described with respect to the RF terminator  100 ,  300 ,  400 ,  500 ,  600 ,  700 ,  800  and/or the resistor assembly  20 ,  200  may be interchanged. 
     In view of the above, it should now be understood that at least some embodiments of the present disclosure are directed to RF terminators that generally include a female connector, an outer housing, at least one support element, a center conductor, a cured resin dielectric, and one or more resistive elements. The female connector is configured to receive a male pin of a coaxial equipment port (not shown) and is disposed within the outer housing and is supported within the outer housing by the at least one support element. The center conductor may include a proximal portion and a distal portion and may be coaxially coupled to the female connector at the proximal portion and encircled by the cured resin dielectric at the distal portion. The cured resin dielectric is cured in place between the center conductor and the outer housing. The one or more resistive elements may be mounted to the center conductor and may be in electrical communication at a first end with the center conductor and at a second end with the outer housing. In this way, an RF signal received from the male pin may travel through the female connector, through the center conductor, through the resistive element, and then to the outer housing, which may be grounded, such that the RF signal is terminated with minimal reflection. As noted above, the cured dielectric resin may be cured in place thereby filling substantially all of the voids between the center conductor and the outer housing or any intervening components, thus providing improved signal isolation and termination. 
     It is noted that the terms “substantially” and “about” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. 
     While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.