Patent Application
20100255717
The present invention is directed to electrical connectors and adapters, and more specifically, to electrical connectors and adapters that exhibit a value of characteristic impedance that is adjustable.
Cable/broadband, telecom, wireless, and satellite industries connect a variety of electrical components, e.g., antennas, amplifiers, diplexers, surge arrestors, with transmission lines, and connectors, to form systems that transmit alternating current electrical signals that can be arranged in an analog and/or digital format. One measure of the success of these systems is the efficiency with which the electrical signals are transmitted amongst these components. Engineers, designers, and technicians in these industries, however, are aware that the level of transmission efficiency that is attained is dependent, in part, on the physical properties of the components that are used in their construction.
Characteristic impedance is one of these properties. More particularly, differences in the characteristic impedance of the components that are connected together can cause problems that affect the transmission efficiency. For example, in a system that includes an antenna, an amplifier, and a transmission line, the differences in the characteristic impedance of the antenna, the amplifier, and the transmission line can cause a portion of the electrical signal transmitted from the amplifier to the antenna to reflect back to the amplifier. This, in turn, can cause standing wave patterns to form in the transmission line when the electrical signal transmitted from the amplifier to the antenna reacts with the electrical signal reflected from the antenna to the amplifier.
Impedance matching is one way to alleviate some of these problems. The goal is to create a system that has a substantially uniform characteristic impedance, which for many systems of the type disclosed and contemplated herein is nominally about 50 ohm, 75 ohm or 90 ohm. Characteristic impedance values that are exhibited by each of the transmission lines and the connectors are determined by a variety of factors, such as, for example, the geometry of the transmission line, the geometry of the connector structure, and the corresponding dielectric material between the conductors. Similarly, the value of characteristic impedance for the connector can be calculated according to the Equation 1 below,
Z=√{square root over (Z1×Z2)}, Equation (1)
where Z is the characteristic impedance of the connector, and Z1 and Z2 are the values of characteristic impedance for various components in the system. Accordingly, creating a system having substantially uniform characteristic impedance includes matching the characteristic impedance values of the transmission lines, e.g., coaxial cable, and the connectors that electrically couple the conductors of the transmission lines with other transmission lines, and with the electrical components.
Unfortunately, although mismatches in the characteristic impedance of the transmission lines and the connectors can degrade the quality of the electronic signal, these mismatches are essentially inevitable. In fact, constraints on cost, manufacturing tolerances, and material selection, among other limitations, cause many connectors that are presently available to exacerbate the problem. Despite these issues, efforts that are directed to better balance the value of characteristic impedance of the components, transmission lines, and in particular the connectors, throughout the system have thus far been unsatisfactory, or have resulted in rigid solutions with limited application in systems utilizing higher frequency regimes.
Therefore, a connector is needed that can facilitate impedance balancing amongst the electrical components in these systems, and more particularly, that can help balance the mismatches in high frequency systems so as to improve signal transmission. It is likewise desirable that, in addition to being configured to support a range of values of characteristic impedance, this connector is robust enough so that it can be implemented in a variety of systems and applications.
The present invention will substantially improve the efficiency that electrical signals are transmitted amongst the components in a system. As discussed in more detail below, connectors that are made in accordance with the concepts of the present invention have a value of characteristic impedance that is adjustable so that the value can be tuned to improve the performance of the system by, for example, changing the return loss of the system.
In accordance with one embodiment, a connector having a characteristic impedance with a first value for use in a system where the characteristic impedance has a nominal value, the connector comprising a conductor extending along a longitudinal axis, a connector body disposed in surrounding relation to the conductor, the connector body including a tuning insulator interface concentric with the longitudinal axis, and a tuning insulator inserted into the tuning insulator interface in a manner encircling at least a portion of the conductor, the tuning insulator having at least one pre-determined effect causing the first value to move toward a second value.
In accordance with another embodiment, a coaxial connector having a value of characteristic impedance, the coaxial connector comprising a conductor extending along a longitudinal axis, a connector body disposed in surrounding relation to the conductor, the connector body including a tuning insulator concentric with the longitudinal axis, and a tuning insulator inserted into the tuning insulator interface in a manner encircling at least a portion of the conductor, the tuning insulator having at least one pre-determined effect causing a first value of the characteristic impedance, wherein the tuning insulator is selected from a plurality of tuning insulators so that the first value substantially equals a nominal value of the characteristic impedance for a system.
In accordance with still another embodiment, a connector system for matching a nominal value of characteristic impedance in a system having at least one component and at least one transmission line, the connector system comprising a connector having a first value of characteristic impedance, the connector including a conductor extending along a longitudinal axis and a connector body in surrounding relation to the conductor, the connector body including a tuning insulator interface concentric with the longitudinal axis, and a plurality of tuning insulators having at least one pre-determined effect causing the first value to move toward a second value when at least one of the tuning insulators encircles the conductor, wherein one or more of the tuning insulators is inserted into the tuning insulator interface in a manner that encircles at least a portion of the conductor.
For a further understanding of the nature and objects of the invention, references should be made to the following detailed description of a preferred mode of practicing the invention, read in connection with the accompanying drawings in which:
Referring now to the figures,
As discussed in more detail below, embodiments of the connector 100 have a characteristic impedance with a value that varies in accordance with changes in the configuration of the connector 100. This is beneficial because the systems in which the connectors of the type used as connector 100 are implemented include a variety of components that each exhibit a characteristic impedance that is often different than the other components of the system. As discussed in the Background section above, these differences can substantially reduce the efficiency with which the electrical signals, e.g., analog and/or digital signals, are communicated throughout the system. Changes in the connector 100, on the other hand, can substantially improve transmission efficiency because such changes tune the value of the characteristic impedance of the connector 100 so as to balance the variations between the other components of the system so that the system exhibits a nominal value of characteristic impedance, which is typically about 50 ohm, 75 ohm, or 90 ohm.
Embodiments of the connector 100 include a connector body 110 with a component side 112 and a transmission line side 114 that is located opposite of the component side 112 on the connector body 110. The connector body 110 is generally elongated in shape, with a preferred construction of the connector body 110 including one or more elongated cylindrical sections that interleave, or overlap, to form a substantially rigid outer shell. The embodiments of connector 100 also include a removably replaceable tuning insulator 116 that is inserted into the connector body 110 on the component side 112. As discussed in more detail herein, the tuning insulator 116 may change the characteristic impedance value of the connector 100.
Insulators of the type used as tuning insulator 116 exhibit certain physical properties that can influence the value of the characteristic impedance of the connector 100. In one example of the tuning insulator 116, at least a portion of the tuning insulator 116 is made of dielectric materials, such as, but not limited to, polycarbonate, polyethelyne, TEFLON®, ULTEM®, and any combinations thereof. Air is also a suitable material, such as, for example, if the connector body 110 does not include any tuning insulator 116. It may be desirable, although not necessary, for the tuning insulator 116 to have a pre-determined effect that causes the value of the characteristic impedance of the connector 100 to change from a relatively low impedance value to a relatively high impedance value. In one example, the pre-determined effect of the tuning insulator 116 causes the value of characteristic impedance of the connector 100 to move from a first value to a second value. Preferably, the pre-determined effect can also cause the value of characteristic impedance for the system to move toward the nominal value of characteristic impedance for the system.
For purposes of example only, when the tuning insulator 116 is in place in the connector body 110, the connector 100 has a first value of characteristic impedance. If the tuning insulator is removed from the connector body 110, then the connector 100 exhibits a second value of characteristic impedance that is less than the first value. Likewise, if the tuning insulator 116 is replaced with another tuning insulator 116 that has a different pre-determined value, then the connector 100 exhibits a third value of characteristic impedance that is different from the first and the second values. Such characteristics of the connector 100 are particularly useful because it permits the value of characteristic impedance of the connector 100 to change within a range of values that can help bring the characteristic impedance of the connector 100 to a value that balances the characteristic impedance of the components in the system.
The component side 112 of the connector body 110 is configured to receive the tuning insulator 116 so that it can influence the characteristic impedance of the connector 100. The connector body 110 can releasably secure the tuning insulator 116 in a manner that prevents the tuning insulator 116 from being removed from the connector body 110 without the application of some type of external force. Although exemplary connectors of the type suited for use as connector 100 may include devices, apparatus, or other implementations to secure the tuning insulator 116 inside of the connector body 110, these are generally unnecessary in preferred embodiments of the connector 100. As discussed in more detail below, in one example of the connector 100, the connector body 110 and the tuning insulator 116 are configured so as to frictionally retain the tuning insulator 116 inside of the connector body 110.
The component side 112 is also configured to engage the component, e.g., the components 104, 106, so that the electrical signals are conducted between the connector 100 and the component 104, 106. Preferably, this also permits the electrical signal to be conducted between the transmission line 108 and the component 106, 109. Exemplary connectors for use as connector 100 typically include connective elements for coupling the connector body 110 to these components, such as, for example, screw-threaded fittings, snap fittings, pressure release fittings, deformable fittings, and any combinations thereof. In one example, the connective element on the component side 112 of the connector body 110 is adapted to mate with threaded receptacles on the components 104, 106. In another example, the connective element is selected from the group of connector interfaces consisting of a BNC connector, a TNC connector, an F-type connector, an RCA-type connector, a 7/16 DIN male connector, a 7/16 female connector, an N male connector, an N female connector, an SMA male connector, and an SMA female connector.
In preferred embodiments of the connector 100, the transmission line side 114 is configured to receive and secure a portion of the transmission line 108 so that the electrical signal is conducted between the connector 100 and the transmission line 108. The connector body 110 may include adaptive connectors that are secured to complimentary components on the transmission line 108. It may also include deformable, and/or adaptable portions that are constructed so that they deform about the transmission line 108 to secure the transmission line 108 in the connector body 110. In one example, the transmission line 108 is inserted into the transmission line side 114 of the connector body 110 so that the conductor (not shown) of the transmission line 108 is in electrical communication with a portion of the connector body 110, such as, for example, the mating conductor (not shown) of the connector 100 that is discussed in more detail below. The transmission line side 114 is then deformed, e.g., using a compression tool (not shown), about the portion of the transmission line 108 to secure the connector body 110 onto the transmission line 108.
A detailed discussion of one embodiment of a connector that is suitable for use as the connector 100 is provided in connection with
In this exemplary implementation, a user, e.g., a technician, can decouple the connector from the component using, for example, hand tools that are consistent with the connective adaptation of the connector side of the connector body. The technician can then insert into the connector, via the connector side, one or more of the exemplary tuning insulators in the kit. This changes the value of characteristic impedance of the connector. In one example, the technician decouples the connector from the component, removes a first tuning insulator that is present in the connector side of the connector body, replaces the first tuning insulator with a second tuning insulator from the kit that has a pre-determined effect that is different that the first tuning insulator, and re-couples the connector and the component.
Referring next to the example of a connector 200 that is illustrated in
In the present example of the connector 200 of
The connector 200 also includes a connective element 240, e.g., threaded nut 240A, that surrounds at least a portion of the tuning insulator interface 238. The threaded nut 240A, as it is illustrated in the present example, is internally threaded so that it can engage the component in a manner that couples the component and the connector body 210. The threaded nut 240A also draws the conductor assembly 226 towards the component so as to facilitate the electrical connection of the component with the connector 200, via electrical contact between the component and the conductor assembly 226, in order to conduct electrical signals amongst the components and transmission lines of the system.
The threaded nut 240A has a first side 242 and a second side 244 that is proximate the insulated interface 238 on the component end 236 of the insulated section 220. As mentioned above, and by way of non-limiting example shown in
The tuning insulator interface 238 has a primary bore 250 and a secondary bore 252 that extend contiguously away from the component end 236 into the insulated section 220. As illustrated in the exemplary embodiment of
Preferably, the inner diameter of the secondary bore 252 is selected so that the secondary bore 252 can insertably receive at least a portion of the tuning insulator 216 therein. More particularly, and as discussed in more detail below, the inner diameter of the secondary bore 252 may be selected so as to cause the inner surface of the secondary bore 252 to frictionally engage the tuning insulator 216. For example, the inner diameter of the secondary bore 252 may be slightly smaller than the outer diameter of the tuning insulator 216 to create an interference fit that slightly compresses the tuning insulator 216 so as to prevent the tuning insulator 216 from falling out of the secondary bore 252.
The conductor assembly 226 includes a support element 256 and a conductor 258 that conducts electrical signals between the transmission line and the component. The support element 260 has an elongated body portion 260 that has an exposed surface 262, and an outer annular portion 264 that surrounds the body portion 260 and that defines an annular surface 266. The conductor 258 has a component portion 268 that electrically communicates with the component, and a line portion 270 that electrically communicates with the transmission line. The elongated body portion 260, and the outer annular portion 264 are generally of circular cross-section, with the outer diameter of the annular portion 264 being sized so that it can fit inside of the bore 234 of the insulated section 220. This enables the conductor assembly 226 to be inserted into the conductor body 210, via the bore 224 of the outer section 220 on the transmission line side 214, and positioned along the longitudinal axis 228 in the insulated section 222 so that the annular surface 266 substantially mates with the stop 234.
For purposes of example only, it is seen in the example of the connector 200 of
The tuning insulator 216 has a substantially cylindrical body 274 that encircles a portion of the conductor 258 so that the tuning insulator 216 is between the conductor 258 and the connector body 210. Although illustrated and described as touching the conductor 258 herein, it may be desirable in other embodiments of the connector 200 that the tuning insulator 216 is in a spaced relationship to the conductor 258, such as, for example, if there is another insulating material (e.g., air) that is located substantially concentrically between the conductor 258 and the tuning insulator 216.
The cylindrical body 274 includes an outer surface 276, a back surface 278, and a front surface 280. The body 274 further has an interior aperture 282, and a plurality of fins 284 that extend towards the center of the aperture 282. Optionally, a projective element 286 is provided that extends substantially away from the front surface 278.
By way of non-limiting example, and as is illustrated in the example of the connector 200 of
Referring now to
Referring next to
Next, the method 400 includes, at step 404, determining if the first value is the value for the return loss that is desired. This may include comparing the first value to a pre-determined threshold level. Examples of the pre-determined threshold level include, but are not limited to, a desired value for the return loss, a maximum value for the return loss, and a minimum value for the return loss, among others. In one embodiment of the method 400, if the first value is equal to about the pre-determined threshold level, or alternatively, it is within a specified acceptable deviation, e.g., about ±0.5, of about the pre-determined threshold level, then the method 400 optionally includes, at step 406, changing the tuning insulator in other ones of connector 300 in the system with a tuning insulator having about the same pre-determined effect as the tuning insulator 316. In another embodiment of the method 400, if the first value is less than about the pre-determined threshold level, then the method 400 optionally continues to step 406. In still another embodiment of the method 400, if the first value is greater than about the pre-determined threshold level, then the method optionally continues to step 406.
If the first value does not meet the pre-determined threshold level in one or more of the manners described above, the method includes, at step 408, adjusting the return loss by changing the tuning insulator 316 in the connector 300. This may include, at step 410, de-coupling the component 304 and the connector 300. In one example, the threaded nut 340A is rotated about the outer section 320 of the connector body 310 in a manner that permits the connector 300 to be removed, either fully or partially, from the component 304. This can be done by hand, or it may require tools, e.g., hand tools, or other devices that can apply a force sufficient to rotate the threaded nut 340A.
The method 400 may also include, at step 412, removing the tuning insulator 316 from the secondary bore 352. In one example, the cylindrical body 374 of the tuning insulator 316 is grasped, or otherwise secured, in a manner that overcomes and/or averts the frictional force between the outer surface 376 and the inner surface of the secondary recess 352. This may be done by hand, such as, for example, by using a finger or fingers to deform the cylindrical body 374, and/or the fins 384 of the tuning insulator 316. In another example, the projective element 386 is grasped, by hand or with hand-tools, and a force is applied that overcomes the frictional forces that retain the tuning insulator 316 in the secondary 352.
The method 400 may further include, at step 414, inserting into the secondary bore 352 another tuning insulator that has a pre-determined effect that is different than the just-removed tuning insulator 316. The new tuning insulator may be selected from a kit, such as the kit discussed above, that includes a plurality of tuning insulators of the type used as tuning insulator 316. Each of the tuning insulators may have a different pre-determined effect on the value of characteristic impedance of the connector 300. If, for example, the return loss of the system must be lowered, then the tuning insulator that is selected will have a pre-determined effect that causes a value for the return loss that is less than the first value caused by the just-removed tuning insulator 316.
After the tuning insulator 316 has been replaced in the secondary bore 352, the method 400 may include, at step 416, re-coupling the component 304 and the connector 300. In one example, the connector 300 is positioned proximate the receptacle on the component so that the threads on receptacle engage the threads on the threaded nut 340A. Here, rotating the threaded nut 340A draws together the receptacle and the tuning insulator interface 238 so that the conductor 356 is electrically coupled to the receptacle on the component.
Method 400 then returns to step 402, measuring a value of the return loss of the system 302, and another value, e.g., a second value, of the return loss of the system is measured that corresponds to the selected tuning insulator. In the present example, the second value is compared to the pre-determined threshold level to determine if the selected tuning insulator in the connector 300 changed the return loss of the system as desired. If the selected tuning insulator does not affect the return loss as desired, and as describe in connection with step 404 above, then the selected tuning insulator is changed, e.g., in accordance with steps 408-416, and the method 400 continues until the value for the return loss that is measured for the system is the value for the return loss that is desired. Then, as discussed above, the method 400 optionally includes, at step 406, inserting a tuning insulator having the same pre-determined effect into other ones of connector 300 that are found in the system.
While the present invention has been particularly shown and described with reference to certain exemplary embodiments, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by claims that can be supported by the written description and drawings. Further, where exemplary embodiments are described with reference to a certain number of elements it will be understood that the exemplary embodiments can be practiced utilizing either less than or more than the certain number of elements.
