The present invention relates generally to transmission line inner conductor support. More particularly, the present invention relates to light weight inner conductor support systems and methods for rigid coaxial transmission lines.
With the advent of digital television, it has become increasingly important that transmission lines carrying broadcast signals to broadcast antennas convey the signals with minimal attenuation and signal distortion. Conventional transmission lines of the broadcast caliber are usually coaxial in nature and very long, being fabricated from joining several smaller coaxial transmission lines together. To maintain the necessary separation between the inner conductor and outer conductor of the coaxial transmission line, series of insulating supports are interspersed within the line at specified locations. The insulating support structures in the coaxial transmission line are subject to several significant loads over their life cycle.
Lines mounted horizontally subject all the supports to a nominal radial load that is proportional to the weight of the inner conductor divided by the number of supporting insulating supports. Lines mounted vertically subject the first support in each section to an axial load at least equal to the weight of the inner conductor plus the forces encountered during the normal differential expansion which occurs between the inner conductor and the outer conductor during power up or power down. Accordingly, for transmission lines that are vertically mounted, the first insulating support or anchor support is subject to a higher load due to axial forces in the transmission line than the load due to radial forces on the individual supports.
Other forms of loads may affect the transmission line such as those associated with the transportation and the installation of the line. For example, it should be understood that radial loads on the individual insulating supports are typically a fraction of the shock load (due to the inertia of the inner conductor) while the axial load on the anchor or end insulator support will equal the entire shock load due to the mast of the inner conductor. Also, there is an axial force called the insertion force associated with the process of forming the connection between successive sections of lines. Again, the axial forces on the anchor or end insulator support is understood to be greatly in excess of the radial loads anticipated on the individual supports.
Also, during the fabrication process, the inner conductor with all its internal support structures must be inserted into the outer conductor and pushed through the entire length of the transmission line section to arrive at its final position. Due to variations or irregularities in the outer conductor diameter or interior finish, for example, the insulating supports are subject to axial forces up to a maximum of the total insertion force (in the case where a single insulating support is the cause of the resistance). These loads are different from the radial loads typically encountered by the inner supports when under normal operating conditions. Therefore, these fabrication loads can be very large and primarily axially directed rather than radially (though there may be an occasional significant radial component).
It should be apparent from the above that the insulating supports' greatest force loading will be due to axial forces rather than conventionally imagined radial forces. In this regard, conventional state-of-the art practices for supporting the inner conductor of rigid coaxial transmission lines have generally been of two types: dielectric pins oriented radially outward from the inner conductor or a disc of dielectric material or puck modified to have mass removed from the interior while retaining sufficient strength to perform the supporting function. These objects are manufactured from an electrically insulating material, generally either of ceramic or plastic composition. The radial forces are carried as compressive loads while axial loads are carried as bending loads, like a beam.
Conventional approaches to addressing the radial and axial loads rising from fabrication and supporting the transmission line have been directed to simply adding to the axial thickness or more material to the supports to accommodate the additional stresses. While the added mass may be effectively compensated for, on the average, by reducing the diameter of the inner section, manufacturing variations become proportionally greater increasing the perturbations of signals in the transmission line.
Therefore, there has been a long standing need in the transmission line community for providing systems and methods for a center conductor support implementation that reduces support mass while providing transmission line integrity.
The foregoing needs are met, to a great extent, by the present invention, wherein difficulties in the prior art are mitigated by using specially configured members to form insulating supports subject to reduced bending and frictional forces. These and other advantages of the invention are discussed in greater detail below.
In accordance with one embodiment of the present invention, systems and methods for an improved coaxial transmission line anchor insulating support are provided by an inner conductor insulating support, comprising an insulating perimeter ring, an outer portion of which is substantially conformal to the outer conductor, an inner portion of which is substantially displaced from the inner conductor, and a plurality of insulating center conductor facing prongs, which are disposed at symmetric angles about the perimeter ring, and extend from the perimeter ring in alternating off-radial angles, the prongs being sufficiently long so as to contact the inner conductor.
In accordance with another embodiment of the present invention, an inner conductor to outer conductor coaxial transmission line insulating support is provided, comprising an insulating perimeter ring, an outer portion of which is substantially conformal to the outer conductor, an inner portion of which is substantially displaced from the inner conductor; and a plurality of insulating center conductor facing prongs, which are disposed at symmetric angles about the perimeter ring and all extend from the perimeter ring at an angle that intersects a common point, the prongs being sufficiently long so as to contact the inner conductor.
In accordance with yet another embodiment of the present invention, a non-anchor inner conductor to outer conductor coaxial transmission line insulating support is provided, comprising a first support member extending from a first member hole in the inner conductor, and a second support member extending from a second member hole in the inner conductor, an outer portion of the second member being joined to the first member at an outer portion of the second member being joined to the first member at an outer portion of the second member to form an angled support, wherein an outer periphery of the joined portion abuts the outer conductor.
In accordance with yet another embodiment of the present invention, an inner conductor to outer conductor coaxial transmission line insulating support is provided, comprising a conically shaped insulating support of sufficient length to abut the outer conductor at the tip of the support, and having base portion conforming to the contour of the inner conductor, and a plurality of prongs disposed about a base of the support, wherein the prongs are matched to holes in the inner conductor.
In accordance with yet another embodiment of the present invention, an inner conductor to outer conductor coaxial transmission line insulating support is provided, comprising a hollow insulating support in the shape of a quadro-pod, wherein edges of the support are substantially thick to form reinforcing ribs, wherein the base of the support is conformed to a contour of the inner conductor and the support having a sufficient height to abut the outer conductor at the top of the support, and a plurality prongs disposed about corners of the base of the support that are co-located with holes in the inner conductor.
In accordance with yet another embodiment of the present invention, an inner conductor to outer conductor coaxial transmission line insulating support is provided, comprising an insulating support having trusses of insulating material to form a truss-like tetrahedral support structure, wherein the base of the support is conformal to a contour of the inner conductor, and the support having a sufficient height to abut the outer conductor at the top of the support, and a plurality of prongs disposed about corners of the base of the support that are co-located with holes in the inner conductor.
In accordance with yet another embodiment of the present invention, a method for supporting an inner conductor within an outer conductor of a coaxial transmission line is provided, comprising the step of inserting an inner conductor support onto an inner conductor, the support having an insulating perimeter ring, an outer portion of which is substantially conformal to the outer conductor, an inner portion of which is substantially displaced from the inner conductor, wherein the insulating support has a plurality of insulating center conductor facing prongs, which are disposed about the perimeter ring, and extend from the perimeter ring in alternating off-radial angles, the prongs being sufficiently long so as to contact the inner conductor.
In accordance with yet another embodiment of the present invention, a method for supporting an inner conductor within an outer conductor of a coaxial transmission line is provided, comprising the step of inserting an inner conductor support over an inner conductor, the support having an insulating perimeter ring, an outer portion of which is substantially conformal to the outer conductor, an inner portion of which is substantially displaced from the inner conductor, wherein the support has a plurality of insulating center conductor facing prongs, which are disposed about the perimeter ring, and extend from the perimeter ring in alternating off-radial angles, the prongs being sufficiently long so as to contact the inner conductor.
In accordance with yet another embodiment of the present invention, a method for supporting an inner conductor within an outer conductor of a coaxial transmission line is provided, comprising the step of inserting an inner conductor support over an inner conductor, the support having an insulating perimeter ring, an outer portion of which is substantially conformal to the outer conductor, an inner portion of which is substantially displaced from the inner conductor, wherein the support has a plurality of insulating center conductor facing prongs, which are disposed about the perimeter ring and all extend from the perimeter ring at an angle that intersects a common point, the prongs being sufficiently long so as to contact the inner conductor.
In accordance with yet another embodiment of the present invention, a method for supporting an inner conductor within an outer conductor of a coaxial transmission line is provided, comprising the step of inserting an inner conductor support over an inner conductor, the support having a first support member extending from a first member hole in the inner conductor and a second support member extending from a second member hole in the inner conductor, an outer portion of the second member being joined to the first member at an outer portion of the second member to form an angled support, wherein an outer periphery of the joined portion abuts the outer conductor.
In accordance with yet another embodiment of the present invention, a method for supporting an inner conductor within an outer conductor of a coaxial transmission line is provided, comprising the step of inserting an inner conductor support over an inner conductor, the support having a conically shaped insulating support of sufficient length to abut the outer conductor at the tip of the support and having base portion conforming to the contour of the inner conductor and a plurality of prongs disposed about a base of the support, wherein the prongs are matched to holes in the inner conductor.
In accordance with yet another embodiment of the present invention, a method for supporting an inner conductor within an outer conductor of a coaxial transmission line is provided, comprising the step of inserting an inner conductor support over an inner conductor, the support having a hollow insulating support in the shape of a quadro-pod, wherein edges of the support are substantially thick to form reinforcing ribs, wherein the base of the support is conformed to a contour of the inner conductor, the support having a sufficient height to abut the outer conductor at the top of the support and a plurality prongs disposed about corners of the base of the support that are co-located with holes in the inner conductor.
In accordance with yet another embodiment of the present invention, a method for supporting an inner conductor within an outer conductor of a coaxial transmission line is provided, comprising the step of inserting an inner conductor support over an inner conductor, the support having an insulating support having trusses of insulating material to form a truss-like tetrahedral support structure, wherein the base of the support is conformal to a contour of the inner conductor, the support having a sufficient height to abut the outer conductor at the top of the support and having a plurality of prongs disposed about corners of the base of the support that are co-located with holes in the inner conductor.
In accordance with yet another embodiment of the present invention, an inner conductor to outer conductor coaxial transmission line insulating support is provided, comprising a first supporting means for securing the inner conductor within the outer conductor, wherein the supporting means is formed of an electrically insulating material and is asymmetrically shaped about the inner conductor, wherein the securing means is affixed via inner conductor-side prongs to a radial sector of the inner conductor via holes in the inner conductor; and a second supporting means for securing the inner conductor within the outer conductor, wherein the supporting means is formed of an electrically insulating material and is asymmetrically shaped about the inner conductor, wherein the securing means is affixed via inner conductor-side prongs to another radial sector of the inner conductor via holes in the inner conductor
In accordance with yet another embodiment of the present invention, a coaxial transmission line is provided, comprising an inner electrical energy conducting means, an outer electrical energy conducting means, and an axial securing means for securing the outer conductor with respect the inner conductor, wherein the outer securing means is formed of an electrically insulating material and is circular about its outer periphery with inner conductor facing opposing prongs about its inner periphery.
In accordance with yet another embodiment of the present invention, a coaxial transmission line is provided, comprising an inner electrical energy conducting means, an outer electrical energy conducting means, and a first a plurality of securing means for securing the inner conductor within the outer conductor, the plurality of securing means being arranged radially along the inner conductor, wherein the securing means is formed of an electrically insulating material and is asymmetrically shaped about the inner conductor, wherein the securing means is affixed via inner conductor-side prongs to the inner conductor via holes in the inner conductor.
There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout.
The exemplary structure 10 has the advantages of being a support structure capable of withstanding the anticipated loads associated with the anchor support. The configuration of the exemplary support structure 10 of
The exemplary anchor support 20 can be considered as a “half image” variant of the support of
Due to the angles employed for the prongs, the beam type loading of the prior art is converted to compression and tensile loads which may be borne by members having significantly reduced cross section and associated mass. Additionally, as stated above, with the decrease in the mass of the insulator support 20, significant reduction of costs and decreases in signal perturbation can be achieved.
Though
Additionally, it should be apparent that in order for the exemplary support 40 to afford complete support between the inner conductor and the outer conductor, a plurality of supports 40 should be placed at various axial locations along the inner and at various radial locations around the inner conductor, possibly at the same location as other supports.
It should be apparent that the above exemplary embodiments provide systems and methods for at least reducing axial stresses on the supports. Accordingly, various types of light weight structures, shapes, configurations exploiting the various support shapes shown above may be implemented according to the knowledge of one of ordinary skill in the art without departing from the spirit and scope of this invention. It should be appreciated that due to the reduced mass of the exemplary supports described herein, significant reduction in cost of dielectric material such as TFE (Teflon) and PFA (Teflon based polymer) which are commonly used in these applications, can be achieved. Other costs and performance related benefits can be achieved depending on the particular choice of materials used.
The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.