The present invention is directed generally to electrical cable connectors, and more particularly to coaxial connectors for electrical cable.
Coaxial cables are commonly utilized in RF communications systems. A typical coaxial cable includes an inner conductor, an outer conductor, a dielectric layer that separates the inner and outer conductors, and a jacket that covers the outer conductor. Coaxial cable connectors may be applied to terminate coaxial cables, for example, in communication systems requiring a high level of precision and reliability.
Coaxial connector interfaces provide a connect/disconnect functionality between (a) a cable terminated with a connector bearing the desired connector interface and (b) a corresponding connector with a mating connector interface mounted on an apparatus or on another cable. Typically, one connector will include a structure such as a pin or post connected to an inner conductor and an outer conductor connector body connected to the outer conductor; these are mated with a mating sleeve (for the pin or post of the inner conductor) and another outer conductor connector body of a second connector. Coaxial connector interfaces often utilize a threaded coupling nut or other retainer that draws the connector interface pair into secure electro-mechanical engagement when the coupling nut (which is captured by one of the connectors) is threaded onto the other connector.
Passive Intermodulation Distortion (PIM) is a form of electrical interference/signal transmission degradation that may occur with less than symmetrical interconnections and/or as electro-mechanical interconnections shift or degrade over time. Interconnections may shift due to mechanical stress, vibration, thermal cycling, and/or material degradation. PIM can be an important interconnection quality characteristic, as PIM generated by a single low quality interconnection may degrade the electrical performance of an entire RF system. Thus, the reduction of PIM via connector design is typically desirable.
As a first aspect, embodiments of the invention are directed to a coaxial connector junction comprising first and second coaxial connectors. The first coaxial connector comprises: a first central conductor extension comprising a substantially cylindrical post; a first outer conductor extension spaced apart from and circumferentially surrounding the first central conductor extension; and a first dielectric spacer interposed between the first central conductor extension and the first outer conductor extension. The second coaxial connector comprises: a second central conductor extension, the second central conductor extension including a substantially cylindrical cavity therein; a second outer conductor extension spaced apart from and circumferentially surrounding the second central conductor extension; and a second dielectric spacer interposed between the second central conductor extension and the second outer conductor extension. The first coaxial connector engages the second coaxial connector, the post of the first central conductor extension being inserted into the cavity of the second central conductor extension such that a capacitive element is created between the first and second central conductor extensions by a gap between the first central conductor extension and the second central conductor extension.
As a second aspect, embodiments of the invention are directed to a coaxial connector junction, comprising a first coaxial connector and a second coaxial connector. The first coaxial connector comprises: a first central conductor extension comprising a post, the post at least partially covered by a first dielectric layer comprising a shrink sleeve; a first outer conductor extension spaced apart from and circumferentially surrounding the first central conductor extension; and a first dielectric spacer interposed between the first central conductor extension and the first outer conductor extension. The second coaxial connector comprises: a second central conductor extension, the second central conductor extension including a cavity therein; a second outer conductor extension spaced apart from and circumferentially surrounding the second central conductor extension; and a second dielectric spacer interposed between the second central conductor extension and the second outer conductor extension. The first coaxial connector engages the second coaxial connector, the post of the first central conductor extension being inserted into the cavity of the second central conductor extension such that a capacitive element is created between the first and second central conductor extensions.
As a third aspect, embodiments of the invention are directed to a coaxial connector junction comprising a first coaxial connector and a second coaxial connector. The first coaxial connector comprises: a first central conductor extension; a dielectric element attached to the first central conductor extension, the dielectric element having a flat contact surface; a first outer conductor extension spaced apart from and circumferentially surrounding the first central conductor extension; and a first dielectric spacer interposed between the first central conductor extension and the first outer conductor extension. The second coaxial connector comprises: a second central conductor extension having a flat contact surface; a second outer conductor extension spaced apart from and circumferentially surrounding the second central conductor extension; and a second dielectric spacer interposed between the second central conductor extension and the second outer conductor extension. The first coaxial connector engages the second coaxial connector, the contact surface of the second central conductor extension abutting the contact surface of the dielectric element attached to the first central conductor extension such that a first capacitive element is created between the first and second central conductor extensions.
The present invention is described with reference to the accompanying drawings, in which certain embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments that are pictured and described herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It will also be appreciated that the embodiments disclosed herein can be combined in any way and/or combination to provide many additional embodiments.
Unless otherwise defined, all technical and scientific terms that are used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the above description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this disclosure, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when an element (e.g., a device, circuit, etc.) is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
Referring again to
The plug 30 includes a central conductor extension 32, an outer conductor extension 34 and an overmold body 40. The central conductor extension 32 has a generally cylindrical post 32a and is mounted on and is in electrical contact with the central conductor 12 of the cable 10 via a boss 33. As can be seen in
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A dielectric layer 144 overlies the outer conductor extension 134 (see
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The central elements when mated form a resonant cavity, which allows the mated plug 30 and jack 130 to be “tuned” to operate beneficially and/or optimally at particular frequencies. This can be achieved by selecting a combination of cavity length, type of dielectric material, thickness of dielectric material, and/or thickness of the air space to provide a desired capacitance. Typically minimizing the air space can provide a broadband improvement in reflection by reducing the distance between the conductors, thus increasing the capacitance. Air gaps may be used when necessary or desirable to allow for ease of insertion given tolerances of the assembled parts.
In some embodiments, air space in the gap g1 and/or the gap g2 can provide a dampening effect during mating of the plug 30 and the jack 130. For example, if the air space in the gap g2 is between about 0.05 and 0.15 mm, air flow from the cavity of the plug 30 upon insertion of the jack 130 is sufficiently restricted that, as insertion proceeds, an air “cushion” is formed. In some prior connectors, and in particular blind-mated connectors (such as blind mated interfaces associated with heavy antenna/radio-head, etc.) there is a danger of the interfaces slamming together and damaging connector parts, brackets, fasteners and the like. With a restricted air flow that creates a built-in air cushion, time is required to allow the air to leak out of the interface. This can produce a “soft” mating, which can eliminate the danger associated with components slamming together.
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In addition to the materials discussed above, exemplary materials for the dielectric layers 44, 144 include other polymeric materials, ceramic materials, and glass. The dielectric strength of the materials of the dielectric layers 44, 144 is typically above about 8 MV/m. Although application as a shrink sleeve is illustrated and described herein, the dielectric layers 44, 144 may be applied in a number of different ways, including painting, spraying, sputter coating, or the like. In some embodiments, the capacitive element is sized and arranged so that it creates capacitance on the order of 10-50 pico farads between the conductor extensions 32, 34 of the plug 30 and the respective conductor extensions 132, 134 of the jack 130.
Although the plug 30 and jack 130 are illustrated herein attached to free coaxial cables 10, 110, in some embodiments one of these connectors may be mounted within a structure, such as a shoulder plate such as that described in co-pending and co-assigned U.S. Patent Publication No. 2013/0065415, the disclosure of which is hereby incorporated herein by reference, that presents multiple connectors at once. Such a shoulder plate or similar mounting structure may be mounted on an antenna, remote radio head or the like.
Referring now to
The plug 230 includes an outer conductor extension 234 similar in configuration to the outer conductor extension 34 of the plug 30. The plug 230 further includes a central conductor extension 232 with a boss 233 that fits over the central conductor 212 of the cable 210. A body 235 is attached to the boss 233. A dielectric spacer 237 is positioned between the body 235 and the outer conductor extension 234. A circular flange 236 extends from the free end of the body 235 opposite the boss 233.
A dielectric disk 244 with a flat contact surface is mounted on the flange 236. The dielectric disk 244 may be formed of any number of dielectric materials. In some embodiments, the dielectric disk may be formed of polyester, PTFE, ceramic, glass or the like. Typically, the dielectric disk 244 is between about 0.001 and 0.003 inches in thickness (the thickness of the dielectric disk 244 is greatly exaggerated in
The jack 330 includes an outer conductor extension 334 that is similar to the outer conductor extension 134 of the jack 130 described above. The outer conductor extension 334 is covered with a dielectric layer 344 similar to the dielectric layer 144 described above (
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Those skilled in this art will appreciate that the plug 230 and jack 330 may take different forms. For example, the central conductor extensions 232, 242 need not have flanges 236, 336 that extend radially outwardly from their respective bodies 235, 335, but instead may present contact surfaces that are the same size or even narrower than the bodies 235, 335. The dielectric disk 244 may be a dielectric elements of another configuration. Also, the dielectric disk 244 may be attached to the central conductor extension 332 of the jack 330 rather than to the central conductor extension 232 of the plug 230. Other variations may also be employed.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.
The present application claims the benefit of and priority from U.S. Provisional Patent Application No. 61/895,113, filed Oct. 24, 2013, the disclosure of which is hereby incorporated herein in its entirety.
Number | Date | Country | |
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61895113 | Oct 2013 | US |