US3828303A

US3828303A - Coaxial connector

Info

Publication number: US3828303A
Application number: US00292856A
Authority: US
Inventors: N Sladek; P Petti; W Zerlin
Original assignee: Bunker Ramo Corp
Current assignee: Amphenol Corp; Bunker Ramo Corp
Priority date: 1972-09-28
Filing date: 1972-09-28
Publication date: 1974-08-06
Anticipated expiration: 1991-08-06
Also published as: FR2204058B1; RO72131A; IL43319A; DE2348645A1; GB1434311A; IL43319A0; HU174266B; FR2204058A1; JPS4971484A; BR7307546D0; CA980888A; AU6073073A; AR196155A1

Abstract

This invention relates to a simple, field installable, low cost, miniature, push-pull, quick connect/disconnect electrical connector system having a VSWR (voltage standing wave ratio) of less than 1.35 for all signal frequencies from 0.1 to 6 GHz useful for interconnecting coaxial cables having a characteristic impedance in the range of 50 ohms. The connector system is made up of a plug member and a jack member each comprising but three basic parts. The first part of each member is comprised of an integral tubular member of relatively soft electrically conductive material. The second part of each member is in turn comprised of a dielectric insert which is held in its respective tubular member by staking or rolling a reduced section of its tubular member''s wall. The front portion of the jack member fits into the front portion of the plug member and through the action of an internal shoulder within the plug member a predetermined spacing between the dielectric inserts held by the plug and jack members is established when the members are fully mated. Each dielectric insert is in turn bored to receive one of two matable pin-like electrical contacts each of which comprises the third part of its respective connector member. Each contact has a hollow rear portion which may be crimped to the center conductor of a respective coaxial cable and thereafter inserted into the bore of its respective insert and retained therein. The outer conductor of each coaxial cable may be crimped around a reduced section of the rear portion of each connector by means of a crimping ferrule. The aforesaid fixed spacing between the dielectric inserts acts to produce a high impedance relative to the impedance afforded by the dielectric inserts to effect the afore-referenced VSWR of less than 1.35 for signal frequencies between 0.1 and 6 GHz.

Description

United States Patent [191 Sladek et a1.

Aug. 6, 1974 COAXIAL CONNECTOR [75] lnventors: Norbert J. Sladek, Fairficld;

Pasquale Ralph Petti, Waterbury; William Max Erich Zerlin, Newtown, all of Conn.

[73] Assignee: Bunker Ramo Corporation, Oak

Brook, Ill.

[22] Filed: Sept. 28, 1972 [2]] Appl. No.: 292,856

[52] US. Cl. 339/177 R, 333/33 [51] Int. Cl H0lr 17/12 [58] Field of Search 333/33; 339/177 [56] References Cited UNITED STATES PATENTS 2,449,073 9/1948 Johannesen 339/l77 R X 3,076,169 l/l963 Blaisdell.. 339/177 R X 3,390,374 6/1968 Forney 339/177 R 3,460,072 8/1969 Ziegler 333/33 3,564,478 2/1971 Hampton 339/217 S X 3,566,334 Z/l97l Ziegler 339/177 R 3,639,889 2/1972 Komadina 339/177 ET OTHER PUBLICATIONS Electro-Technology, Burndy Connectors December, 1962, page 183, copy in 339-177 R.

Primary Examiner-Francis K. Zugel Assistant Examiner-Lawrence J. Staab Attorney, Agent, or FirmD. R. Bair; R. J. Kransdorf; F. M. Arbuckle [57] ABSTRACT This invention relates to a simple, field installable, low

cost, miniature, push-pull, quick connect/disconnect electrical connector system having a VSWR (voltage standing wave ratio) of less than 1.35 for all signal fre' quencies from 0.1 to 6 GHz useful for interconnecting coaxial cables having a characteristic impedance in the range of 50 ohms. The connector system is made up of a plug member and a jack member each comprising but three basic parts. The first part of each member is comprised of an integral tubular member of relatively soft electrically conductive material. The second part of each member is in turn comprised of a dielectric insert which is held in its respective tubular member by staking or rolling a reduced section of its tubular members wall. The front portion of the jack member fits into the front portion of the plug member and through the action of an internal shoulder within the plug member a predetermined spacing between the dielectric inserts held by the plug and jack members is established when the members are fully mated. Each dielectric insert is in turn bored to receive one of two matable pin-like electrical contacts each of which comprises the third part of its respective connector member. Each contact has a hollow rear portion which may be crimped to the center conductor of a respective coaxial cable and thereafter inserted into the bore of its respective insert and retained therein. The outer conductor of each coaxial cable may be crimped around a reduced section of the rear portion of each connector by means of a crimping ferrule. The aforesaid fixed spacing between the dielectric inserts acts to produce a high impedance relative to the impedance afforded by the dielectric inserts to effect the afore-referenced VSWR of less than 1.35 for signal frequencies between 0.1 and 6 GHz.

7 Claims, 6 Drawing Figures COAXIAL CONNECTOR This invention relates to an electrical connector adapted for mating a pair of coaxial cables and more particularly to an inexpensive quick connect/disconnect coaxial connector with minimum reflections (and thus low voltage standing wave ratio, VSWR) at frequencies up to six GHz.

BACKGROUND OF THE INVENTION The characteristic impedance of a coaxial transmission line is normally about 50 ohms. In order to avoid impedance mismatches, the impedance through all sections of a connector joining two coaxial lines should thus also be substantially 50 ohms. Where impedance mismatches do occur through sections of a coaxial connector, reflections may occur, adversely effecting the voltage standing wave ratio (VSWR) of the connector and resulting in attenuation of any signal passing through the connector. The attenuation caused by an impedance mismatch increases significantly as the frequency of the line signal increases. Thus, an impedance mismatch which may be acceptable in a connector intended for low frequency applications, becomes unacceptable when an attempt is made to utilize the connector with higher frequency lines.

Heretofore, the requirement of obtaining a substantially uniform 50 ohm impedance through a coaxial connector has required fairly careful design and manufacture. The resulting connector has therefore been relatively expensive. Lower cost connectors, such as standard phono-connectors, have heretofore been limited to applications with line frequencies no greater than 0.5 GHZ. However, even these phone-connectors are relatively expensive, and in applications such as in mobile radio where frequencies above 0.5 GHz are utilized, these connectors are clearly inadequate.

A need therefore exists for a simple, inexpensive radio frequency coaxial connector which provides minimum reflections and thus acceptable VSWR and performance at frequencies up to six GHz. Normally, a connector will be considered to have acceptable VSWR and performance if VSWR is less than 1.35 over the entire frequency range that the connector is intended to operate in (for example, 0.1 to 6 GHz). Such a connector should also provide for quick connect and disconnect, while still providing reliable mating.

SUMMARY OF THE INVENTION This invention therefore provides an electrical connector adapted for mating a pair of coaxial lines which connector includes a plug and a jack. The plug has a male center contact, a cylindrical outer contact projecting beyond the center contact and having at least one tine biased toward the center of the contact, and an insert of an insulating material mounted in the outer contact and having an axial opening in which the center contact is supported. The jack has a female center contact dimensioned to have the male contact fit snugly therein, a cylindrical outer contact dimensioned to fit into the plug outer contact with the tine in pressure engagement with the outer wall thereof, and an insert of insulating material mounted in the outer contact and have an axial opening in which the center contact is supported. The plug and jack are dimensioned to provide a small air gap between their inserts of insulating material when the plug and jack are fully mated.

The impedance of the air gap is slightly greater than the characteristic impedance of the lines while the impedance of the inserts are slightly less than the characteristic impedance of the lines. This results in the vector sum of the reflections due to the insert and gap inpedances in a mated connector pair being very small (i.e., a VSWR of less than 1.35). The balancing of impedance mismatches in conjunction with the minimizing of the length of the impedance mismatch area permits an inexpensive connector to be provided which connector achieves the required performance parameters.

' The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side view of the plug portion of v a connector of a preferred embodiment of the invention.

FIG. 2 is a front view of the plug shown in FIG. 1.

FIG. 3 is a sectional side view of the jack portion of a connector of a preferred embodiment of the invention.

FIG. 4 is a front view of the jack shown in FIG. 3

FIG. 5 is a sectional side view of the connector of the preferred embodiment of the invention showing the plug and jack in a mated condition.

FIG. 6A is a sectional side view of the center contact portion of the jack for an alternative embodiment of the invention.

FIG. 6B is a portional sectional side view of the center contact portion of the plug for the embodiment of the invention shown in FIG. 6A.

DETAILED DESCRIPTION Referring now to FIGs.,1 and 2, it is seen that the plug 10 for the connector of a preferred embodiment of the invention consists of a one-piece tubular body member 12 of a conducting material, an insert 14 of an insulating material staked at four places 16 (only two of which are shown in FIG. 1) near the center of body 12, and a center contact 18 of a conducting material supported in an axial bore 20 formed through insert 14. The forward or contact portion 22 of body 12 is slotted to provide a pair of upper and lower sections each of which extends for approximately and a pair of tines 26 which are each biased toward the center of body. The leading surface of each section 24 and tine 26 is slightly flared to assist in the insertion of a mating jack. The rear portion 28 of body 12 is tapered and, as may be seen in FIG. 5, is adapted to fit between the outer conductor 32 and insulator 30 of a coaxial cable or line 34. Portion 28 has a bore 36 sized to accept the cable insulation 35. Bore 36 terminates in a counterbore ,38 in which is positioned insert 14. Counterbore 38 terminates in a second counterbore 40 in the outer contact region 22 of the body. A shoulder 42, the function of which will be described later, is formed at the juction between

counterbores

38 and 40. A crimp ferrule 44 is provided to secure outer conductor 32 of the cable to portion 28 of body 12.

Center contact 18 has a rear opening 46 in which center conductor 48 of cable 34 is either soldered or crimped. The center contact is then passed through the rear of the connector and forced through opening 20 to position the contact as shown. A barb 49 is formed near the center of contact 18 to prevent the contact from being withdrawn once it has been so positioned (i.e., to captivate the contact in the connector). The forward contact portion 50 of the contact 18 has a tapered bullet-shaped leading edge for easy insertion into a mating female contact and is, as best seen in FIG. 2, cross-slotted. This permits the contact to compress slightly when being inserted into a mating female contact to provide good pressure contact therewith.

Jack 52 (FIGS. 3 and 4) also has a one-piece body 54, an insulating insert 56, a center contact 58 and a crimp ferrule 60. Body 54 has a cylindrical forward contact portion 62 with a tapered leading surface for insertion into contact portion 22 of plug and an extending rear or ferrule portion 64 with a tapered trailing edge which, as is seen in FIG. 5, is adapted to be fitted between the insulation and outer conductor of a coaxial cable 34. Body 54 also has a bore 66 with an enlarged counterbore 68 in its forward portion. Insert 56 is positioned in the rear of counterbore 68 and is held therein by being staked at four points 70 (only two of which are shown in FIG. 3). Insert 56 has an axial bore 72 in which is supported center contact 58. Center contact 58 is in the form of a hollow tube having a pair of pierced tabs 74 which serve to captivate the contact in the jack once the contact has been passed through the rear of insert 56. As with the plug, center conductor 48 of the cable is secured in contact 58 by either soldering or crimping and outer conductor 32 is secured to portion 64 of body 54 by crimping ferrule 60 over the outer conductor in standard fashion.

All parts of plug 10 and jack 52 are of a conductive material such as brass except inserts l4 and 56 which are of an insulating material such as polytetrafluoroethylene (also known by the trademark Teflon). The brass parts may be coated with nickel to reduce corrosion.

Referring now to FIG. 5, it is seen that when the parts are fully assembled, the leading edge of jack outer contact 62 bottoms on shoulder 42 of plug 10. This leaves an air gap 76 in the mated connectors between insert 56 and insert 14 which is equal to the width of

counterbores

68 and 38 not filled by the respective inserts. For preferred embodiments of the invention, the insert fills about 60 percent of the counterbore and the air gap the remaining 40 percent. However, since the total length of each counterbore, for the preferred embodiment of the invention, is less than a quarter of an inch, the total length of the impedance mismatch is relatively short. The impedance of the air section is roughly 62 ohms and the impedance of the insert section (assuming Teflon as the insert material) is roughly 44 ohms. As a result, the vector summation of the reflections through the mismatch area is small, the reflections introduced in one mismatched section tending cancel those introduced in the other mismatched section with little substantial net adverse effect resulting on the applied signal. Connectors built utilizing the design described above have been found to have a VSWR of less than 1.20 (in most instances less than 1.15) over a frequency range from 0.1 to 6 GHz. Thus, these connectors are, in accordance with standards previously mentioned, adapted for providing acceptable performance at frequencies up to six GHz.

FIGS. 6A and 6B illustrate the center contact portions of a jack and plug respectively of an alternative embodiment of the invention. Female center contact 80 of the jack 54 for the alternative embodiment of the invention, is machined from rod stock rather than being a hollow tube. This contact has a rear opening 82 formed in it which is adapted to have the center conductor 48 of a coaxial cable 34 secured therein in the same manner that a conductor is secured in opening 46 of contact 18. Contact 80 also has a forward opening 84 which is slotted so as to be adapted for expansion, and a barb or ring 86 formed around its circumference which barb is identical to and performs the same functions as barb 49. In the alternative, barb 86 may be of reduced size and positioned further back on contact 80 so that it remains within insert 56 when the contact is properly positioned. With either configuration, the barb tends to hold the contact against movement in jack 54.

The center contact 88 of plug 12' is identical to center contact 18 of plug 12 (FIG. 1) except that forward contact portion 90 is in the shape of a solid tapered bullet rather than a slotted tapered bullet. Contact portion 90 is sized so as to cause a slight expansion of opening 84 when contact portion 90 is fitted therein assuring a good pressure fit between contacts 80 and 88.

The connectors described above are adapted to be quickly connected by merely pushing the plug and jack together and to be quickly disconnected by pulling these two elements apart. No predetermined orientation of parts, screwing, clamping, or other operations are required. Tines 26 being in pressure contact with the outer wall of contact area 62 of jack 52 assure a good physical and electrical connection of the outer conductors while the compression of slotted bullet contact 50 on entering tubular contact 58 or the expansion of slotted contact 80 when contact 88 enters it assures good physical and electrical contact under pressfi of the inner contacts There is a wiping action on both the inner and outer conductors during connect and disconnect which removes contaminents and further assures good electrical contact. Barb 49 and tabs 74 or barb 86 restrict movement of their center contacts in the connectors to within about 16 mils minimizing the adverse VSWR effects of such movement.

Since the plug and the jack of the connector of this invention have only three parts each, plus a crimp ferrule, which parts are assembled using simple and straightforward techniques, both the material and assembly costs for the connector of this invention are minimized. An extremely low cost, simple, quick connect/disconnect, high perfonnance RF coaxial connector has thus been provided.

While the description above has been with reference to preferred embodiments of the invention, it is apparent that some modifications in the details of the design may be made. For example, the number of tines 26 may be varied from as little as one to as many as four or five. Similarly, a single cut rather than a crosscut may be utilized for the tip 50 of contact 18. Thus, while the invention has been shown and described above with reference to preferred embodiments, the foregoing and other modifications may be made in the connector of this invention by those skilled in the art while still remaining within the spirit and scope of the invention.

What is claimed is:

1. An improved low cost quick connect/disconnect electrical connector having a VSWR of less than 1.35 for all signal frequencies from 0.1 to 6 GHz, including a plug member and a jack member which, when in axial alignment with one another, may be pushed together or pulled apart to interconnect or disconnect two coaxial cables each of substantially the same characteristic impedance, the coaxial cables having an inner conductor and an outer conductor separated by a body of dielectric material, said plug member comprising a first, a second and a third plug parts;

said first plug part having a front, central and rear axially extending portions contiguous with one another and being formed of an integral tubular body of relatively soft resilient electrically conductive material, said tubular body having an axial bore extending through the rear portion thereof, said bore having an internal diameter substantially equal to the outer diameter of the dielectric body of one coaxial cable to permit said dielectric body to be snugly received within the rear portion of said tubular body, a section of said rear portion of said body contiguous with the rear extremity thereof being reduced sufficiently to accept a crimping ferrule for holding the outer conductor of said coaxial cable against the outer periphery of said reduced rear seciton and to form an external laterally extending shoulder against which a crimping ferrule may be longitudinally seated and restrained from axial movement toward the front portion of said tubular body;

said tubular body having a first counterbore extending through the central portion thereof, said first counterborehaving an internal diameter greater than said bore in said rear portion to form a first internal laterally extending shoulder located at the rear extremity of said first counterbore and the front extremity of said bore, at least a portion of said central portion being reduced on its outer periphery near said rear portion to form a first wall of Y said relatively soft material which is defined between the inner surface ,of said first counterbore and the outer surface of said reduced central portion and which is inwardly deformable by externally staking or rolling said wall;

said tubular body having a second counterbore extending through the front portion thereof, said second counterbore having a diameter larger than said first counterbore to form a second internal laterally extending shoulder located at the rear extremity of said second counterbore and the front extremity of said first counterbore against which the front extremity of a jack member may abut when said plug and said jack member are pushed together and mated, the internal diameter of said second counterbore and the external diameter of said front portion forming a resilient second wall of said conductive material longitudinally slit and formed to grip said jack member when inserted therein by spring action;

said second plug part comprising a cylindrical insert of resilient dielectric material having a diameter substantially equal to that of the first counterbore of said first plug part and positioned within the central portion of said first plug part against said first internal laterally extending shoulder, said insert having a length less than the axial length of said first plug part central portion and retained therein by deformation of said first wall into gripping relation with the outer periphery of said insert, said insert having a central bore for receiving said third plug part;

said third plug part comprising an electrically conthe jack member of said connector system comprising a first, second and third jack parts;

said first jack having a front and a rear axially extending portions contiguous with one another and being formed of an integral tubular body of relatively soft resilient electrically conductive material, said tubular body having an axial bore extending through the rear portion thereof, said bore having an internal diameter substantially equal to the outer diameter of the dielectric body of another coaxial cable to permit said dielectric body to be snugly received within the rear portion of said tubular body, a section of said rear portion of said body contiguous with the rear extremity thereof being reduced sufficiently to accept a crimping ferrule for holding the outer conductor of said coaxial cable against the outer periphery of said reduced rear section and to form an external laterally extending shoulder against which a crimping ferrule may be longitudinally seated and restrained from axial movement toward the front portion of said body;

said tubular body having a counterbore extending through the front portion thereof, said counterbore having an internal diameter greater than said rear portion bore to form a first internal laterally extending shoulder located at the rear extremity of said counterbore and the front extremity of said bore, at least a portion of said front portion being reduced on its outer periphery near said rear end portion to form a first wall of said relatively soft material which is defined between the inner surface of said counterbore and the outer surface of said reduced front portion and which is inwardly deformable by externally staking or rolling said wall;

said second jack part comprising a cylindrical insert said third jack part comprising an electrically conductive contact member matable with the contact member carried by said plug member and having a hollow rear portion for accepting and retaining the inner conductor of the other of said coaxial cables and a front end portion formed to pass through from the rear of said first jack part and be axially restrained from rearward movement therein within the bore of said second jack part after the inner conductor of said coaxial cable has been retained in said hollow rear portion thereof, the spacing between the front surfaces of the dielectric inserts in said plug member and said jack member when said members are mated forming an impedance which is greater than the characteristic impedance of said coaxial cables with the dielectric constant of said inserts and the lengths thereof forming impedances which are less than the characteristic impedance of said coaxial cables whereby said plug member and said jack member when mated provide a connector system having a VSWR of less than 1.35 for all signal frequencies from 0.1 to 6 GHZ.

2. A connector system according to claim 1 wherein said second plug part and said second jack part have substantially the same dimensions.

3. A connector system according to claim 1 wherein said first wall of said first jack part is substantially the same thickness as the depth of said second internal laterally extending shoulder of said first plug part with the outer diameter of a section of the front portion of said first jack part being substantially equal to the inner diameter of the second counter-bore of said first plug part.

4. A connector system according to claim 1 wherein said front end portion of said electrically conductive contact retained by said plug member extends beyond said second internal laterally extending shoulder within said first plug part but is contained substantially wholly within said front portion of said first plug part and wherein the extremity of said front end portion of said contact member carried by said second jerk part extends beyond the front extremity of the dielectric insert forming said second jack part but is contained substantially wholly within said front end portion of said first jack part.

5. A connector system according to claim 1 wherein the outer periphery of said first jack part is provided with a tapered surface extending rearwardly from the front extremity of the front portion thereof to a position forward of the forward extremity of said second jack part to aid in the insertion thereof into the front portion of said first plug member.

6. A connector system according to claim 1 wherein the characteristic impedance of the coaxial cables to which said connector members are to interconnect is substantially 50 ohms while the impedance formed by the spacing of said dielectric inserts are in the range of 62 ohms and the impedance formed by each of said dielectric inserts is in the range of 44 ohms.

7. A connector system according to claim 1 wherein the volume embraced between said dielectric inserts is substantially 40 per cent and the volume occupied by said dielectric inserts is substantially per cent respectively of the total volume embraced within said connector system between said first internal shoulder of said first plug part and said first internal shoulder of said first jack part when said plug and jack member are fully mated.

Claims

1. An improved low cost quick connect/disconnect electrical connector having a VSWR of less than 1.35 for all signal frequencies from 0.1 to 6 GHz, including a plug member and a jack member which, when in axial alignment with one another, may be pushed together or pulled apart to interconnect or disconnect two coaxial cables each of substantially the same characteristic impedance, the coaxial cables having an inner conductor and an outer conductor separated by a body of dielectric material, said plug member comprising a first, a second and a third plug parts; said first plug part having a front, central and rear axially extending portions contiguous with one another and being formed of an integral tubular body of relatively soft resilient electrically conductive material, said tubular body having an axial bore extending through the rear portion thereof, said bore having an internal diameter substantially equal to the outer diameter of the dielectric body of one coaxial cable to permit said dielectric body to be snugly received within the rear portion of said tubular body, a section of said rear portion of said body contiguous with the rear extremity thereof being reduced sufficiently to accept a crimping ferrule for holding the outer conductor of said coaxial cable against the outer periphery of said reduced rear seciton and to form an external laterally extending shoulder against which a crimping ferrule may be longitudinally seated and restrained from axial movement toward the front portion of said tubular body; said tubular body having a first counterbore extending through the central portion thereof, said first counterbore having an internal diameter greater than said bore in said rear portion to form a first internal laterally extending shoulder located at the rear extremity of said first counterbore and the front extremity of said bore, at least a portion of said central portion being reduced on its outer periphery near said rear portion to form a first wall of said relatively soft material which is defined between the inner surface of said first counterbore and the outer surface of said reduced central portion and which is inwardly deformable by externally staking or rolling said wall; said tubular body having a second counterbore extending through the front portion thereof, said second counterbore having a diameter larger than said first counterbore to form a second internal laterally extending shoulder located at the rear extremity of said second counterbore and the front extremity of said first counterbore against which the front extremity of a jack member may abut when said plug and said jack member are pushed together and mated, the internal diameter of said second counterbore and the external diameter of said front portion forming a resilient second wall of said conductive material longitudinally slit and formed to grip said jack member when inserted therein by spring action; said second plug part comprising a cylindrical insert of resilient dielectric material having a diameter substantially equal to that of the first counterbore of said first plug part and positioned within the central portion of said first plug part against said first internal laterally extending shoulder, said insert having a length less than the axial length of said first plug part central portion and retained therein by deformation of said first wall into gripping relation with the outer periphery of said insert, said insert having a central bore for receiving said third plug part; said third plug part comprising an electrically conductive contact having a hollow rear portion for accepting and retaining the inner conductor of one of said coaxial cables and a front end portion formed to pass through from the rear of said firSt plug part and be axially restrained from rearward movement within the bore of said second plug part after the inner conductor of said coaxial cable has been retained in said hollow rear portion thereof; the jack member of said connector system comprising a first, second and third jack parts; said first jack having a front and a rear axially extending portions contiguous with one another and being formed of an integral tubular body of relatively soft resilient electrically conductive material, said tubular body having an axial bore extending through the rear portion thereof, said bore having an internal diameter substantially equal to the outer diameter of the dielectric body of another coaxial cable to permit said dielectric body to be snugly received within the rear portion of said tubular body, a section of said rear portion of said body contiguous with the rear extremity thereof being reduced sufficiently to accept a crimping ferrule for holding the outer conductor of said coaxial cable against the outer periphery of said reduced rear section and to form an external laterally extending shoulder against which a crimping ferrule may be longitudinally seated and restrained from axial movement toward the front portion of said body; said tubular body having a counterbore extending through the front portion thereof, said counterbore having an internal diameter greater than said rear portion bore to form a first internal laterally extending shoulder located at the rear extremity of said counterbore and the front extremity of said bore, at least a portion of said front portion being reduced on its outer periphery near said rear end portion to form a first wall of said relatively soft material which is defined between the inner surface of said counterbore and the outer surface of said reduced front portion and which is inwardly deformable by externally staking or rolling said wall; said second jack part comprising a cylindrical insert of resilient dielectric material having a diameter substantially equal to that of said first jack part counterbore and positioned within said counterbore against the laterally extending shoulder therein, said insert having a length less than the axial length of said first jack part front portion and retained therein by deformation of said wall into gripping relation with the outer periphery of said insert, said insert having a central bore for receiving said third jack part; said third jack part comprising an electrically conductive contact member matable with the contact member carried by said plug member and having a hollow rear portion for accepting and retaining the inner conductor of the other of said coaxial cables and a front end portion formed to pass through from the rear of said first jack part and be axially restrained from rearward movement therein within the bore of said second jack part after the inner conductor of said coaxial cable has been retained in said hollow rear portion thereof, the spacing between the front surfaces of the dielectric inserts in said plug member and said jack member when said members are mated forming an impedance which is greater than the characteristic impedance of said coaxial cables with the dielectric constant of said inserts and the lengths thereof forming impedances which are less than the characteristic impedance of said coaxial cables whereby said plug member and said jack member when mated provide a connector system having a VSWR of less than 1.35 for all signal frequencies from 0.1 to 6 GHz.

3. A connector system according to claim 1 wherein said first wall of said first jack part is substantially the same thickness as the depth of said second internal laterally extending shoulder of said first plug part with the outer diameter of a section of the front portion of said first jack part being substantially equal to thE inner diameter of the second counterbore of said first plug part.

7. A connector system according to claim 1 wherein the volume embraced between said dielectric inserts is substantially 40 per cent and the volume occupied by said dielectric inserts is substantially 60 per cent respectively of the total volume embraced within said connector system between said first internal shoulder of said first plug part and said first internal shoulder of said first jack part when said plug and jack member are fully mated.