JPH0456435B2 - - Google Patents

Abstract

A coaxial electrical connector, particularly suited for high frequency ''blind-mate'' connections, remotely located connections, multiple connector assemblies and quick connect-disconnect applications, having two mating plug halves (32, 34), each plug having an inner conductor (46, 75), an outer conductor (42, 44) and a dielectric spacer (68, 70) therebetween, the inner and outer conductor on each plug being of unequal lengths such that one projects beyond the other; the longer inner conductor from one plug and the longer outer conductor form the other plug being designed to overlap each other when the connector is first electrically connected and only partially engaged (Fig. 3), thereby defining an overlap region (54, 56, 58, 60); the inner and outer conductors being shaped and the dielectric material of the spacers being chosen such that along the axis of the partially engaged connector, particularly in the overlap region, the effective outer diameter of the inner conductor (''d'') and the effective inner diameter of the outer conductor (''D'') and the dielectric constant of the material therebetween (''E'') satisfy the equation: Z = 138 (E)<-1/2> log (D/d), where Z is the impedance and is substantially constant along the length of the connector as the plugs (32, 34) are moved from the first electrically connected, partially engaged position to the fully engaged position.

Description

DISCLOSURE OF THE INVENTION According to the invention, a connector is provided with a first plug connecting to a co-operating second plug.
The first plug as shown can be considered a female plug, however, due to the design of an optional shield on the male plug that makes the female connection, the terms first and second plugs are confusing. used to avoid. Each plug is provided with an inner conductor, an outer conductor and a dielectric spacer between them, and in each the inner and outer conductors are different at their free ends such that one projects beyond the other. It is ivy length. The inner and outer conductors of the first plug are designed to cooperate with the inner and outer conductors of the second plug. The plugs are designed such that the longitudinal inner conductors and longitudinal outer conductors from the first and second plugs overlap each other when the connectors are first electrically connected and partially engaged. This creates an overlap between the inner conductor from one plug and the outer conductor from the other plug. The inner and outer conductors are particularly shaped with relative diameters d and D, and the dielectric member of the spacer fills along the axis of the partially engaged connector, particularly within the overlap region. The effective outer diameter d of the inner conductor, the effective inner diameter D of the outer conductor, and the dielectric constant ε of the medium between them satisfy the formula Z=138(ε) ^-1/2 log(D/d) . Here, Z is an impedance and is constant along the length of the connector as the plug is first electrically connected and moved from a partially engaged position to a fully engaged position.

[Brief explanation of the drawing]

The details of the invention will be explained in conjunction with the accompanying drawings. FIG. 1 is a perspective view of a connector according to the invention. This figure hides some important features of the invention which are only shown in longitudinal section. FIG. 2 is a longitudinal cross-sectional side view taken primarily along line 2--2 of FIG. FIG. 3 is a longitudinal cross-sectional view of the connector showing the first and second plugs partially engaged. 4 and 5 are lines 4-- in FIG. 2, respectively.
4 and 5-5 are end views of the open co-operative or "free" end of the connector at line 5-5. FIG. 6 is a longitudinal sectional view showing one of the conventional connectors. FIG. 7 is a longitudinal cross-sectional view of three connector blocks employing connectors of the present invention, one of the connectors not fully engaged.

[Detailed description of the invention]

1 Conventional Connector FIG. 6 shows a simplified longitudinal section of a conventional connector. A discussion of this connector and the problems associated with incompletely splicing the connector will assist in understanding the present invention. The conventional connector shown in FIG. 6 is composed of a male plug 10 and a female plug 12. The male plug has an outer conductor 14 having an inner diameter D ₁ and an outer diameter coaxially aligned with the outer conductor.
and an inner conductor 16 having a diameter of d ₁ . The female plug 12 also comprises, in most of its body, an outer conductor 18 and an inner conductor 20 having exactly the same diameters D ₁ and d ₁ as in the male plug. The space between the inner and outer conductors is filled with a dielectric member 22 having a dielectric constant ε. Although in this simplified example the dielectric member is shown extending throughout the interior of the plug, in many connectors only a portion of each plug is filled with dielectric material and the remaining portion is open. The dielectric material in this part is air. In any event, the plugs shown in FIG. 6 are shown incompletely engaged with a small gap between the plugs. As mentioned above, the characteristic impedance of the male plug is expressed by the formula: Z=138(ε) ^-1/2 log(D ₁ /d ₁ ). This equation also represents the characteristic impedance of the male portion 12 of the connector, so that when the plug is fully installed, the male outer conductor 14 and the female outer conductor 18 are in plane Z24. ，
Similarly, inner conductors 16 and 20 abut each other at faces 28, 30, thereby providing a constant impedance along the length of the connector. However, as mentioned above, it is not possible to guarantee complete engagement of the connector;
Therefore, a gap as shown in FIG. 6 will occur. In the region between, the outer conductor 18 of the female plug has an enlarged inner diameter D ₂ . Similarly, the inner conductor 16 of the male plug is connected to the male plug 10 and the female plug 1.
The reduced outer diameter required to make the connection between 2
Has pd ₂ . Therefore, the impedance of the connector is expressed by the formula, Z _gap = 138 (ε _air ) ^-1/2 log (D ₂ /d ₂ ) in the region between . Due to the positional relationships shown in FIG. 6, all three parameters ε, D, d are different in the cage region between ≓ compared to their values in other parts of the transmission line and connector, and 3
All of them make inappropriate changes that increase the impedance Z _gap . In particular, the dielectric constant of air (ε _air )
is overall smaller than the permittivity of most commonly used solid dielectrics, thereby increasing the factor (ε) ^-1/2 . Furthermore, the increased D and d between 〓 together act to increase the ratio D ₂ /d ₂ , thereby increasing the factor log(D ₁ /d ₁ )
The factor log(D ₂ /d ₂ ) is increased compared to . As a result, all three factors act to increase the impedance Z _gap , thereby creating an impedance mismatch that causes signal degradation. In this simplified example, all three parameters D, d, and ε were changed to create a mismatch; however, changing any one of the parameters over time can cause problems at high frequencies. is sufficient. Embodiment of Connector FIG. 1 shows a perspective view of a connector according to this embodiment. There are many important features of the connector that are hidden in the external view shown in FIG. Nevertheless, this diagram is useful for understanding the general orientation with respect to the connector. The connector is composed of a first plug 32 and a second plug 34. Each of the two plugs has a different diameter enlarged ring 36, 38 about it, which is connected to a connector housing (not shown), primarily for use in mutiple connector modular assemblies. (shown generally in the figure). The first plug is connected to the shield 4 having a slot 42.
0, and the slot 42 is provided with the shield 40 during manufacturing.
can be compressed slightly, thereby causing the outer conductor 4 of the second plug 34 to compress when the plug is engaged.
Make a solid electrical connection with 4. Also visible on the first plug 32 is a portion of the free end of the inner conductor 46 of the first plug, which free end is the end that connects to the other plug. Similarly, the second plug 34 has its outer conductor 4
Part 8 is shown. However, in this figure, the illustrated end of the inner conductor 48 is not a free end, but an end for connection to a coaxial transmission line. This end can have any known standard shape for connecting to a coaxial transmission line. The end may be straight or bent at a right angle, and is typically soldered to provide a good, low-loss, substantially constant impedance connection between the coaxial transmission line and the second plug. be done. A similar connection is made on the distal side of the first plug 32 (first
(not shown) and its corresponding coaxial transmission line. FIG. 2 is a side view of the connector taken along line 2--2 shown in FIG. This figure is shown mostly in cross-section to illustrate important features of the invention. For purposes of explanation, the first plug 32 has the reference number 5.
It is divided into four regions designated 0-56, which are divided into four regions designated with reference numbers 58-64.
This corresponds to four areas of the plug 34. In a preferred embodiment, the first plug 32 has four separate mechanical parts: an inner conductor 4;
6, an outer conductor 66, a shield 40, and a dielectric spacer 68. The second plug 34 is comprised of three parts including an inner conductor 48, an outer conductor 44, and a dielectric spacer 70. Regions 50 and 64 of the first and second plugs, respectively, are coaxial cable connection regions, ie, the regions where signals first pass from the coaxial cable into or out of the connector. As aforementioned,
These regions are designed with standard technology to work with specific coaxial cables and have precise impedances to effectively transmit signals to the first and second plugs, respectively. Typically, to make this connection, the outer conductor and dielectric members of the coaxial cable are stripped back from the inner conductor of the coaxial cable. The inner conductor of the coaxial cable is inserted into the axial aperture indicated by reference numeral 72 and into the inner conductor 46 of the first plug 32 . A corresponding axial aperture 73 is provided in the inner conductor 48 . To the left of region 50 and to the right of region 64, the signal passes through a path defined between the inner and outer conductors of the coaxial cable. Within regions 50 and 64, between the shield 40 and the inner conductor 72 of the first plug 32 and the outer conductor 4 of the second plug 34.
4 and an inner conductor 48 . The space between these regions is filled with air. It should be appreciated that in the first plug 32, the leftmost portion of the shield 40 in region 50 acts as the outer conductor and defines a critical diameter D in that region. Referring to Figure 3, the precise diameter D ₃ /d ₃ is
It is shown that the impedance of the connector in region 50 is defined by the equation, Z=138(ε _air ) ^-1/2 log(D ₃ /d ₃ ). The diameters D and d in region 64 may be similar to those in region 50 and have the same ratio since the dielectric material is the same (air) in both regions.
Must have D ₃ /d ₃ . However, in the preferred embodiment, they differ slightly from D ₃ and d ₃ to simplify assembly of the final connector. Regions 52 and 62 are dielectric spacer regions in which the space between the inner and outer conductors of each plug is filled with dielectric spacer.
The dielectric spacer is suitably made of Teflon, but may also be made of many suitable dielectric materials well known for use in high frequency connectors. Dielectric spacers hold the connectors together to hold the inner conductors in axial alignment with the center of each plug. Since the dielectric constant of the preferred Teflon is greater than that of air, the diameter D ₄ , d ₄ in region 52 (see FIG. 3) is adjusted to match the impedance of region 50 and the coaxial cable itself. It must be adjusted to maintain impedance. Therefore, in the region 52, the diameters D ₄ and d ₄ are determined by (ε _teflpo ) ^-1/2 log (D ₄ /d ₄ ) = (ε _air ) ^-1/2 log (D ₃ /d ₃ ). selected. This kind of precise adjustment of the diameters D and d as the dielectric constant changes from one region to the other is known. An important feature to note is that the transition from diameter D ₃ to D ₄ does not lie exactly in the same plane as the transition from diameter d ₃ to d ₄ as would be expected. This deviation in the transition of the inner and outer conductors means that the impedance equations described above are completely accurate for the measured diameters D and d only in regions where the electric field lines are arranged substantially radially in the connector. Therefore, the necessary adjustments can be extracted empirically. This means that the inner diameter and outer diameter (d
and D) occur only where there is no sudden change. In the region where the diameters d and D change rapidly causing the electric field lines to depart from their radial alignment, the formula does not give completely accurate results. Near sharp corners of the faces of the inner or outer conductors, the electric field lines tend to concentrate towards the corners, and thus the "effective" inner and outer diameters d, D are smaller than the actual diameters measured in the radial direction. It's slightly different. Essentially, the "effective" diameter d,D indicates the actual impedance around a rapid change in the actual diameter D,d when applied to the above equation. However, the effective diameter is very close to the actual diameter, even at sharp transition points in the actual diameter. In areas where the actual dimensions do not change, the effective diameter is equal to the actual diameter. Usually the actual diameter is used to calculate the impedance of the connector. However, the effective diameter must be controlled, even though most engineers designing such connectors do not distinguish between the two. As a result, in order to maintain a constant impedance through the region where the conductor diameter changes, it is necessary to offset the diameter changes of the inner and outer conductors by a small amount based on the degree of diameter change that is created. This need is well known to coaxial connector designers and means making fine adjustments to the ideal situation where the two diameter changes occur in the same plane. This adjustment can be easily accomplished through experience in the industry. The regions indicated by reference numerals 54 and 60 are referred to herein as "free space" regions. As in region 50, in region 54 the relative diameters D ₅ , d ₅ as shown in FIG. 3 are again selected to match the characteristic impedance of the rest of the connector. As in region 50, the dielectric member between inner conductor 46 and outer conductor 66 is air, so the ratio D ₅ /d ₅ must be the same as the ratio D ₃ /d ₃ . As shown in FIG. 2, the outer conductor 66 of the region 54 has a slot 74 that allows the free end of the outer conductor 66 to be slightly enlarged, thereby allowing the outer conductor of the second plug 44 to open at its free end. Make an electrical connection with the inside of the In region 56 , the inner conductor of first plug 46 projects beyond outer conductor 66 . As best shown in FIG. 3, the protruding end of inner conductor 46 in region 56 is enlarged in region 56 and has an outer diameter d ₆ that is greater than outer diameter d ₅ in region 54 . As clearly shown in FIG. 2, inner conductor 66 stops short of region 56. The outer shield conductor 40 does not form part of the signal path when the connector is connected. Accordingly, the protruding portion of the inner conductor 46 having a diameter d ₆ in the region 56, as its corresponding outer conductor, in the region 58 the outer side of the second plug having an inner diameter D ₆ as shown in FIG. It has a conductor 44. Referring to the second plug in FIG. 2, a similar action of the second plug on the first plug is shown. Here, the signal flows from the right side to the left side of FIG. 2, from the coaxial cable into the connector as described above, from area 64 to area 62 and then to area 60. These areas 60-64
have the same characteristic impedance as the corresponding regions 50-54 of the coaxial cable and first plug. Just like the first plug, the inner and outer conductors 48, 44 of the second plug are of unequal length.
In the second plug, the longitudinal conductor has an outer conductor 44 that projects beyond the inner conductor 48 in region 58.
It is. Again, as in region 56, in protruding region 58, the protruding member, ie the second plug, has a precise change in its diameter as outer conductor 44 passes from free space 60 to region 58. For the outer conductor 44, the precise diameter is:
The inner diameter D has changed to a reduced diameter D ₆ in region 58 compared to the corresponding larger inner diameter D in region 60 . In a preferred embodiment, regions 54, 56, 58
and 60 all have substantially the same length;
Thus, when connecting the connector, the outer conductor 44 in the region 58 of the second plug slides into the shield 40 of the first plug until the two outer conductors 66 and 44 connect with each other. Near this location, inner conductors 46 and 48 are also connected and the connector forms an electrical connection. When this electrical connection is made, the connector has an overlap defined by the overlap between regions 56 and 58. In this region, the enlarged protruding portion of the inner conductor 46 and the outer conductor 44
The reduced protrusion forms a transition signal path between the two plugs with a characteristic impedance defined by the ratio D ₆ /d ₆ . These diameters are chosen to provide an impedance match with the impedance of the rest of the connector, and this match is
Even when the connector is partially engaged,
This creates an essentially constant impedance along the length of the connector. Connector “just-barely”
When sliding from the engaged position to the fully engaged position, the overlap area between regions 56 and 58 is dimensionally reduced such that outer conductor 44 slides over outer conductor 66, and the signal path cease to function as a part. Similarly, the protruding end of inner conductor 46 also slides into inner conductor 48 and ceases to function as part of the signal path. It is clear that the lengths of the overlapping connectors can be made as appropriate with any desired tolerances for the connectors. In a preferred embodiment, regions 54, 56, 58, and 60 are all approximately
It is 0.10 inches (2.5 mm) long, which is a sufficient dimension to more than compensate for the variation in engagement depth of the two plugs that may occur in any of the previously described applications. The preferred lengths of regions 54, 56, 58, and 60 all provide about 10 times more compensation than in conventional compensation designs. There is no need to fully engage the connector since the overlap portion is designed to form part of the signal path with impedance matching with other portions of the connector. It is highly desirable for the connector to be used in an application configuration in which it is always partially engaged. As shown in FIGS. 3 and 5, the free end of the inner conductor 48 may be provided with a slot 75. This end can then be lightly compressed to make an electrical connection with the free end of the inner conductor 46.
Compression or expansion of all slots and slotted members best shown in FIGS. 4 and 5 is optional and may be adjusted accordingly to suit the application configuration. When the various components of the connector are manufactured,
The conductor components are typically plated and assembled with a good conductive oxidation resistant material such as gold.
The dielectric spacers 68, 70 may be retained by adhesive or by lightly crimping or scoring the surface of the outer conductor. The connector according to the invention works very well at frequencies above 1 GHz and has also passed tests at at least 18 GHz. FIG. 7 shows a plurality of connectors of the present invention, designated by reference numerals 76, 78, and 80. A first plug of each connector is attached to connector block 82 and a second plug is attached to connector block 84. Typically, connector block 82 is attached to the back of the electronic device and connector block 84 is inserted to the back of the frame into which the electronic device is inserted, such that the connector connects the electronic device to the frame. It will be connected when Connectors 76 and 80 as shown in FIG.
Although fully engaged, connector 78 is shown only partially engaged due to misalignment, manufacturing tolerance, or the like. Therefore, the area designated by reference numeral 86 would be the area that would create an impedance mismatch across the connector 78 in the case of a conventional connector, but in the connector of the present invention, however, this would be part of the signal path. An overlap region designed to form a 100% 200 µm 200 µm, with a characteristic impedance that matches the impedance of the rest of the connector and the transmission line.

Claims (1)

[Claims] 1. Consisting of a first plug and a second plug, the first plug has a first inner conductor having a free end for coupling with a second inner conductor, and a second outer conductor. a first outer conductor having a free end for coupling with a body; and a first dielectric spacer between the first inner conductor and the first outer conductor; a free end of the first inner conductor; protrudes beyond a free end of the first outer conductor; a second plug for coupling to the first plug; a second inner conductor having a free end for coupling to the first inner conductor; a second outer conductor having a free end for coupling with the first outer conductor; and a second dielectric spacer between the second inner conductor and the second outer conductor; The free end protrudes beyond the free end of the second inner conductor, and the protruding portion of the first inner conductor and the protruding portion of the second outer conductor partially engage the connector to form an overlapping portion. overlap each other when defining the ratio of the inner diameter D of the protruding portion of the second outer conductor to the outer diameter d of the protruding portion of the first inner conductor and the dielectric constant ε in the overlapped portion such that the impedance in the overlapped portion is The formula is
An electrical coaxial connector characterized in that it is selected in a relationship that satisfies Z=138(ε) ^-1/2 log(D/d). 2 The protruding portion of the first inner conductor has an outer diameter greater than the outer diameter of the non-protruding portion of the first inner conductor, and the protruding portion of the second outer conductor has a larger outer diameter than the outer diameter of the non-protruding portion of the second outer conductor. The electrical coaxial connector of claim 1, wherein the electrical coaxial connector has an inner diameter smaller than the inner diameter. 3. The electrical coaxial connector of claim 2, wherein the first outer conductor is slidably coupled to the inside of the protrusion of the second outer conductor. 4. The first outer conductor is slightly enlarged in diameter by being slotted at its free end so as to be coupled to the inside of the free end of the second outer conductor. Electrical coaxial connector. 5. The electrical coaxial connector according to claim 2, wherein the protruding portion of the first inner conductor is slidably coupled to the second inner conductor. 6. The electrical device of claim 5, wherein the free end of the second inner conductor is slotted and slightly reduced in diameter so as to be coupled to the outside of the free end of the first inner conductor. coaxial connector. 7. The electrical coaxial connector of claim 1, wherein the length of the protruding portion of the first inner conductor is substantially the same as the length of the protruding portion of the second outer conductor. 8. The electrical coaxial connector of claim 1, wherein the first and second dielectric spacers are formed of Teflon. 9. An electrically conductive shield substantially surrounding the protruding portion of the first inner conductor and configured to cooperate with the exterior of the free end of the second outer conductor when the plug is engaged. The electrical coaxial connector of claim 1, further comprising: 10. The electrical coaxial connector of claim 9, wherein the shield is slotted and slightly reduced in diameter at the free end of the second outer conductor so as to be coupled to the outside of the free end of the second outer conductor. . 11. The electrical coaxial connector of claim 1, wherein the overlapping portion forms part of the signal path when the connector is fully engaged as well as when the connector is only partially engaged. 12. The plurality of electrical coaxial connectors of claim 1, wherein at least one plug of each connector is mounted to a connector block. 13. The plurality of electrical coaxial connectors of claim 12, wherein the first and second plugs of each connector are attached to a corresponding connector block, and all connectors are connected and disconnected substantially simultaneously. 14 Outer diameter d _first is smaller than outer diameter d _secpod
d smaller than _pverlap , and the inner diameter D _first is the inner diameter
14. The electrical coaxial connector of claim 13, having an inner diameter smaller than D _pverlap which is smaller than D _secpod . 15 Consisting of a first plug and a second plug, the first plug includes a first inner conductor and a first outer conductor that are coaxially mounted, and the first outer conductor has an inner diameter D _first. , the first inner conductor has a protruding portion having an outer diameter d _pverlap that projects beyond the first outer conductor and an outer diameter d _first
the second plug has a second inner conductor and a second outer conductor coaxially mounted, the second inner conductor has an outer diameter d _secpod ; The outer conductor has a protruding portion having an inner diameter _Dpverlap that projects beyond the second inner conductor and an inner diameter.
D _secpod having a non-protruding portion, the protruding portions of the first inner conductor and the second outer conductor overlapping each other to define an overlapping portion when the connector is partially engaged; Ratio, D _first /d _first and D _secpod /d _secpod and D _pverlap /d _pverl
AP is an electrical coaxial connector characterized by being substantially the same in all respects. 1 Technical Field The present invention relates to coaxial electrical connectors, and more particularly, to connectors that can be quickly connected/disconnected;
The present invention relates to suitably non-mating high frequency connectors, such as modular parallel connector assemblies for electrically coupling two modules together to form mutiple coaxial connections. 2 BACKGROUND OF THE INVENTION Coaxial transmission lines and the connectors used therewith generally include cylindrical inner and outer conductors that are axially aligned and separated by a dielectric member. The dielectric within the cable is generally a flexible solid foam that holds the inner conductor in the center of the cable and allows the cable to flex and bend as needed. The dielectric material in the connector is generally a combination of solid matter in one portion of the connector and air in the remaining portion to hold the electrical conductors. A coaxial transmission line or connector as described above is
The outer diameter of the inner conductor (hereinafter referred to as a lowercase letter "d"),
The inner diameter of the outer conductor (hereinafter referred to as a capital letter "D"),
and a characteristic impedance determined by the dielectric constant (hereinafter referred to as the Greek letter "ε") of a member in the space between the two conductors forming the signal path. As is well known, the characteristic impedance of a coaxial transmission line is expressed by the formula: Z=138(ε) ^-1/2 iog(D/d) where N is the impedance of the line. Determined by The connector has a characteristic impedance along its length that matches the impedance of the transmission line as defined by the formula above to minimize signal disruption such as signals passing through the connector. must also have. Impedance mismatch is especially important for 1G
Severe signal destruction occurs at high frequencies above Hz. As mentioned above, high frequency coaxial connectors are generally
The area between the inner and outer conductors is air, and the space between the inner and outer conductors is filled with insulation, such as Teflon, to keep the inner conductor in coaxial alignment with the outer conductor. It includes at least a portion that is another region filled with a dielectric solid. The dielectric constant of Teflon is different from that of air, and the dielectric constant of air is different from that of insulating dielectric members used in coaxial cables. However, as long as the impedance defined by the above equation remains constant, signal corruption is kept to a minimum. In a connector, this requires mutual adjustment of the dimensions d and D at each location where the dielectric constant changes in order to keep the impedance Z constant. Virtually all conventional connectors have constant diameters d and D between the two halves of the connector, i.e., the male and female plugs, at the transition site from one plug to the other. It relies on making a butt joint at the intersection of the inner and outer conductors to maintain the same. The term "butt joint" in this description refers to a continuous joint when two opposing faces of a male plug and a female plug connect the connector with no gaps between the two faces. In such connectors, the dielectric constant ε is also generally the same on both sides of the male to female plug transition. The requirement to maintain a constant impedance along the length of an engaged connector is achieved by ensuring that the distance between the plugs is small enough to be ignored at the highest frequencies at which the connector is intended to operate. has been done. In a typical coaxial connector design, the outer conductor of the female plug is enlarged at its free end (thereby increasing D). This allows the outer conductor of the male plug to slide into the enlarged diameter outer conductor of the female plug, and creates an abutment between the end of the male connector and the inner edge of the outer conductor of the female connector. Create a bond (as well as a good mechanical and electrical connection). A similar arrangement exists for the inner conductor where the free end of the inner conductor of the male plug generally has a reduced diameter portion (reducing d) for fitting into the axial hole of the inner conductor of the female plug. . In order to make a successful connection in such conventional connectors, the plug must be fully seated and there is essentially no gap between the butt joints between the inner and outer conductors of the male and female plugs. Must not be. The increased D and reduced d of the outer and inner connectors can be ignored only if the outer and inner connectors have a substantially closed gap. In such conventional connectors, even with a relatively narrow gap, the diameter D between the gaps is necessitated by mechanical design limitations of the connector, especially at high frequencies.
Uncontrolled changes in and d substantially destroy the signal passing through the connector by creating an impedance mismatch between . To close the gap between mating connectors, many high frequency connectors rely on threads on one plug and a threaded collar on the other plug, which are engaged to close the gap between the two connectors. must be tightened with a specific torque so as to reduce the gap to a small value to an acceptable limit. Unfortunately, in many proposals, it is not practical to completely install each connector with a torque wrench. A distinct problem lies in parallel connectors and "blind-mate" or remotely located connectors or those requiring quick connection operations. Parallel connections that must be made simultaneously may not allow one or more parallel connectors to be fully installed, even if the remaining connectors are properly placed. A "blind coupling" connector is, for example, a connector used behind a sliding module that makes all the necessary connections as the module slides into place. Such connectors are "remotely located" in the sense that one of the fasteners on the front of the module or the back of the module is located with the other connector located in the frame in which the module is installed. The placement mechanism that determines the depth of insertion of one plug into the other is therefore "remotely located" from the plug itself. Making tolerance variations or simple distortions in the mounting frame all directly affect the distance between the two plugs. To overcome these obstacles, coaxial connector designers have devised various methods to minimize the interspace dimensions. For example, U.S. Pat. No. 4,426,127, issued to Kubota, discloses that the intervening portion between the male and female inner conductors as well as the intervening portion between the female outer conductors, even over a small range of movement between the two plugs, A coaxial connector is disclosed that is filled with a spring member that deforms to minimize the distance between conductors. However, this configuration still uses an abutment-type connection and always leaves open the risk of deviations in diameters D and d at the transition from male to female plug. The spring mechanism is approximately 0.010~0.015in (0.25~
Effective only over very short distances (0.38 mm). Unfortunately, gaps beyond the range compensated for by this feature are extremely common in parallel connector and module examples such as those described above. Thus, the present invention employs a novel design in which the inner and outer conductors of the male and female plugs do not have to "match" each other. Instead,
The conductors are designed to form an overlap between the two plug sections that corresponds generally to that between traditional connectors, with the overlap forming part of the signal path and matching the rest of the connector. It is intentionally designed to have an impedance of Therefore, the connector will have a constant impedance along its entire length, the two parts will first be electrically engaged, and the dimensions of the "interval" or overlap will not affect the impedance of the connector. It can be made as large as necessary.