Patent Application
20090066598
This invention relates generally to feed horns, and more particularly, to methods for manufacturing a modular waveguide feed horn.
A waveguide is a structure that guides waves, such as electromagnetic waves, light or sound waves. For example, an acoustic waveguide generally includes a duct or other similar structure for sound propagation and that directs the waveguide. The acoustic waveguide typically includes a feed horn, which is a horn antenna that is used to convey radio waves between, for example, a transmitter or receiver and a reflector. As an example, in radio transmission, the feed horn operates as an open-ended waveguide that is generally of increasing cross-sectional area and that radiates directly in a desired direction or feeds a reflector that forms a desired beam. For example, feed horns may have one or more expansion curves, for example, longitudinal cross sections, such as elliptical, conical, hyperbolic or parabolic curves. Accordingly, different beam patterns may be formed by controlling the dimensions and shapes of the feed horns. Essentially, the feed horn defines a portion of the waveguide in which the cross-section is smoothly increased (e.g., linearly or exponentially increased) along the axial direction, thereby defining an increasing cross-sectional area.
Current waveguide feed horn assemblies are fabricated from a single piece of metal (e.g., aluminum). The fabrication involves extensive precision computer numerical control (CNC) machining and wire electrical discharge machining (EDM) processes. In particular, the CNC machining is performed on an entire piece of metal and the EDM process forms the internal waveguide features. This machining process results in a single assembly or unit forming the feed horns on a waveguide plate. This process is not only time consuming, but significantly increases the cost of the assembly due in part to the wasted metal that is machined away during the fabrication process.
In one embodiment, a waveguide feed horn assembly is provided that includes a waveguide plate section. The waveguide feed horn assembly also includes a feed horn section including at least one feed horn. The feed horn section is separately provided from and removably coupled to the waveguide plate section.
In another embodiment, a feed horn is provided. The feed horn includes an upper funneled portion and a lower engagement portion having a conductive gasket.
In yet another embodiment, a method for providing a waveguide feed horn assembly includes forming a waveguide plate. The method further includes forming at least one feed horn separate from the waveguide plate and that is configured to be removably coupled to the waveguide plate.
For simplicity and ease of explanation, the invention will be described herein in connection with various embodiments thereof. Those skilled in the art will recognize, however, that the features and advantages of the various embodiments may be implemented in a variety of configurations. It is to be understood, therefore, that the embodiments described herein are presented by way of illustration, not of limitation.
As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.
Various embodiments of the invention provide a modular molded waveguide feed horn assembly having a multiple piece design, for example, a two piece design. The modular molded waveguide feed horn assembly 20 (or a portion thereof) is shown generally in
Referring to
It should be noted that the feed horns 26, whether formed from plastic, metal or other material may be coated or plated. For example, the feed horns 26 may be metal plated using any suitable process to provide an electrical signal path to ground through the waveguide plate section 24 as described in more detail below. Any suitable conductive finish may be used, for example, gold, silver, copper nichrome (CuNiCr), nickel, chem.-film, etc. These materials may be applied through any known plating process, for example, electro-plating, plasma vapor deposition (PVD), etc. The feed horns 26 are essentially provided with a metallization of the functional surfaces of the feed horn 26 to provide electrical signal conductivity when assembled to the waveguide plate section 24. The waveguide plate section also may be assembled to a circuit board (not shown), for example, a printed circuit board. The feed horns 26 may be plated individually or as groups and may be entirely plated or partially plated. For example, each feed horn module 28 may be plated at one time. Also different types of plating materials may be used, for example, a different plating material inside and outside the feed horn 26. If the feed horns 26 are formed of a metal material, the metal plating also acts to resist oxidation and corrosion and may be plated using, for example, copper nichrome (CuNiCr) (which also may be used to plate plastic feed horns 26). Alternatively, the metal feed horns 26 (e.g., aluminum feed horns 26) may be plated with a chemical film coating, sometimes referred to as a Chem Film. For example, a chromate conversion coating may be applied to aluminum surfaces of the metal feed horns 26.
The feed horns 26 each also include a gasket 40 as shown in
The gasket 40 may be formed from any material providing an electrical ground contact at the interface of the feed horn 26 and a bottom surface of the waveguide plate section 24 (shown in
The lower engagement portion 32 also includes a notch 46 as shown in
The lower engagement portion 32 in one embodiment has a generally rectangular cross-section configured to engage within the opening 48 of the waveguide plate section 24. However, the lower engagement portion 32 may have different cross-section shapes, for example, oval, circular, triangular, etc. with the opening 48 have a corresponding shape. As shown in the embodiments of
A mounting opening 54 (e.g., bore) is also provided between groups (e.g., pairs) of feed horns 26. For example, the mounting opening 54 may be provided in an offset orientation relative to the feed horns 26 and formed in a connection member 56 (e.g., a connection arm) between the feed horns 26. A corresponding opening 60 (shown in
The feed horns 26 are mounted to the waveguide plate section 24 as shown in
The feed horn modules 28 are configured such that when mounted to the waveguide plate section 24 (e.g., slip fit engagement), the feed horn modules 28 are aligned in abutting arrangement to form an array of feed horns 26 as shown in
Thereafter, the waveguide plate section 24 may be mounted to a device, system, component, etc. For example, the waveguide plate section 24 then may be connected to a printed circuit board used to control communication of signals through the feed horns 26.
Thus, various embodiments of the invention provide feed horns that are separate units from a waveguide plate and coupled thereto in different numbers. Accordingly, less material (e.g., metal) is wasted when machining the waveguide plate. The number of feed horns also may be increased or decreased as desired or needed. For example, when using the feed horns in an imaging device or application, such as an x-ray scanner or thermal imaging scanner, increasing the number of feed horns provides higher image resolution.
It should be noted that modifications and variations to the various embodiments are contemplated. For example, the shape and size of the feed horns may be modified based on the particular application, use, etc. For example, the geometry of the feed horns affects the transmission and reception properties. Thus, the internal design of the fed horns may be modified based on transmission frequency requirements.
Accordingly, it is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description.
The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
