Patent Application
20240030576
The present disclosure relates generally to microwave devices and, more particularly, to a waveguide device used for absorbing electromagnetic wave energy, such as waveguide termination devices, and to methods of manufacturing such a device.
In microwave fields, waveguide termination devices are employed to terminate a transmission line with a substantially matched load which is capable of absorbing and dissipating electromagnetic waves (also known as radio frequency (RF) signals) transmitted into the load. As a waveguide termination device prevents electromagnetic waves from reflecting back from open-ended or unused waveguide ports, a reflection, measured in terms of voltage standing wave ratio (VSWR), within the waveguide termination device may be reduced significantly.
Conventionally, in order to provide a substantially matched load in a waveguide system, loads or absorber elements made of different kinds of material or with various shapes may be attached within the waveguide termination device and establish a thermal contact with the housing of the termination device to achieve a desired amount of absorption. Traditional approaches, such as standard brazing or adhesive techniques, are typically used to secure the absorber elements to the waveguide termination device. For example, U. S. Patent U.S. Pat. No. 4,906,952A describes that energy absorbing wedges may be retained in contact with walls of a waveguide with an adhesive. As another example, U.S. Pat. No. 3,904,993A describes that a load may be attached to a waveguide using standard brazing techniques. The contents of the aforementioned documents are incorporated herein by reference.
The housings of the waveguide termination devices are typically made of a material (e.g., aluminum, copper, brass, or bronze) with a relatively high thermal expansion coefficient, the housing of the waveguide termination device may expand longitudinally and/or radially as temperatures of the housing increases. This is particularly present in cases where the waveguide termination devices are used in high-power applications, such as 4 kW or 8 kW continuous-wave (CW) or any suitable carrier wave energy, since a signification amount of heat is generated and must be absorbed. In such cases, the absorber elements secured to the interior surfaces of the housing, for example by brazing or adhesive techniques, may become partially or fully detached as the housing expands longitudinally and/or radially and thus the thermal contact between the absorber elements and the housing is reduced. In addition, as a result of the reduced thermal contact and thus poor heat conductivity, local overheating of the absorber elements, the mechanical fragility of the absorber elements, and/or the expansion of the housing may cause physical damage in the absorber elements, such as brokage or cracking. Thus, performance (e.g., VSWR and/or impedance match) of the waveguide termination device may deteriorate significantly.
Furthermore, in a case when the absorber elements are physical damaged, the entire waveguide termination device may need to be replaced, which leads to increased hardware maintenance costs.
Accordingly, there is a need in the industry to provide an improved waveguide termination device that alleviates at least in part some of the deficiencies of existing waveguide termination devices.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify all key aspects and/or essential aspects of the claimed subject matter.
In accordance with a first aspect, the present disclosure relates to a waveguide device for absorbing electromagnetic wave energy. The waveguide device comprises one or more projections that extends into a hollow passage of a housing to exert respective resilient forces on one or more absorber elements such that each absorber element is urged against a respective interior side wall of the housing. Since the respective resilient forces caused by the corresponding projection urge the absorber element against the respective interior side wall of the housing, an attachment between the absorber element and the interior side wall is easily removable. The absorber element will no longer deform by expansion impact of the housing's side walls. The side wall may include any interior wall of the housing. In the example of a housing having a rectangular cross section, broad interior walls or narrow interior walls of the housing are referred to as side walls. Thus, physical damages, such as broken or cracking, of the absorber element may be avoided without sacrificing performance of the waveguide device over a wide range of operation frequencies.
In some examples, as the absorber element is removable from the housing of the device, the absorber element may be easily replaced with any other suitable absorber element. Thus, substituting an entire waveguide device may be prevented in a case where the absorber elements have physical damages or when other absorber elements are needed to achieve a desired characteristic of the waveguide device. Therefore, flexibility of manufacturing the waveguide device may be improved, and hardware cost of the waveguide device in a waveguide system may be reduced.
In some applications, the waveguide device may be applied in high power applications, such as medical applications, signal combination, system switch protection, couplers, magic tee, isolator, power test setup.
According to a first example aspect is a waveguide device. The device comprises an elongated housing an elongated housing including a first end and a second end. The first end is a power receiving end. The elongated housing defines a hollow passage. The device further comprises an absorber element that is disposed within the passage of the housing along an interior surface of the housing. The absorber element is configured to absorb at least some energy of the electromagnetic waves traveling through the hollow passage. A projection is also included in the device to extend into the passage. The projection is configured to exert a resilient force on the absorber element to urge the absorber element against the interior surface of the housing.
In accordance with the preceding aspect, the projection extending into the passage is a first projection. The first projection is positioned at a first location along an extent of the elongated absorber element. The waveguide device further comprises a second projection extending from the elongated housing into the passage. The first and second projections are spaced apart from one another. The second projection is positioned at a second location along the extent of the elongated absorber element. The second projection is configured to exert a second resilient force on the elongated absorber element to urge the elongated absorber element against the interior surface of the housing.
In accordance with any of the preceding aspects, the projection extending into the passage is one of a plurality of projections extending from the elongated housing into the passage. The projections in the plurality of projections are positioned at respective locations along an extent of the elongated absorber element. The plurality of projections are spaced apart from one another. The plurality of projections are configured to exert resilient forces on the elongated absorber element to urge the elongated absorber element against the interior surface of the housing. The plurality of projections includes at least three projections.
In accordance with any of the preceding aspects, the plurality of projections are linearly arranged along the hollow passage.
In accordance with any of the preceding aspects, the elongated absorber element has a tapered profile and the plurality of projections are linearly arranged at an angle along the hollow passage. The angle matches the tapered profile of the absorber element.
In accordance with any of the preceding aspects, the housing is made of conductive metal.
In accordance with any of the preceding aspects, the projection is made of conductive metal.
In accordance with any of the preceding aspects, the absorber element is made of lossy material.
In accordance with any of the preceding aspects, the housing and the projection are made of aluminum, copper, brass, bronze, or invar.
In accordance with any of the preceding aspects, the absorber element is made of silicon carbide, ceramic, or lossy resin.
In accordance with any of the preceding aspects, the projection is a part of a distal end of a screw extending from the housing into the hollow passage. The screw is inserted through an aperture formed on an outer surface of the elongated housing so that the part of the distal end of the screw corresponding to the projection extends into the passage.
In accordance with any of the preceding aspects, the screw further includes a proximal end, a threaded component and the distal end, the threaded component being positioned between the proximal end and the distal end, at least a portion of the projection being characterized by a resilience greater than a resilience of the threaded component of the screw thereby being configured for exerting the resilient force on the absorber element.
In accordance with any of the preceding aspects, a diameter of at least the portion of the projection is less than a diameter of the threaded component of the screw.
In accordance with any of the preceding aspects, at least part of the projection is made of first material and wherein the threaded component is made of second material, a modulus of resilience of the first material being higher than a modulus of resilience of the second material.
In accordance with any of the preceding aspects, the projection includes a first portion and a second portion. A diameter of the first portion is less that a diameter of the second portion.
In accordance with any of the preceding aspects, a modulus of resilience of the first portion being higher than a modulus of resilience of the second portion.
In accordance with any of the preceding aspects, the waveguide device further comprises an E-bend assembly connected the power receiving end of the housing.
In accordance with any of the preceding aspects, the elongated absorber element includes a tapered side extending from the second end of the elongated housing to the first end of the elongated housing so that a thicker end of the elongated absorber element is positioned at the second end of the housing.
In accordance with any of the preceding aspects, the elongated absorber element extends for substantially an entire length of the elongated housing.
In accordance with any of the preceding aspects, the elongated absorber element is a first absorber element and the interior surface of the housing is a first interior side wall of the housing. The first elongated absorber element is disposed against the first interior side wall of the elongated housing. The waveguide device further comprises a second elongated absorber element. The second absorber element is disposed against a second interior side wall of the elongated housing. The second interior side wall is arranged opposite to the first interior side wall of the second interior side wall housing.
In accordance with any of the preceding aspects, the waveguide device further comprises at least one cooling system attached at an exterior surface of the elongated housing and being thermally coupled to said housing.
In accordance with any of the preceding aspects, the at least one cooling system includes a fluid circulation path configured for circulating a cooling liquid. The cooling liquid is configured for absorbing heat from the elongated housing.
In accordance with any of the preceding aspects, the cooling liquid is water.
In accordance with any of the preceding aspects, the power receiving end includes a flange radially extending from the elongated housing.
In accordance with any of the preceding aspects, the flange includes an O-ring configured to seal a space between the flange and a transmission line of a waveguide system.
In accordance with any of the preceding aspects, the absorber element extends along the extent of an interior side wall of the housing.
In accordance with any of the preceding aspects, the elongated housing includes two opposite broad interior walls and two opposite narrow interior walls. The interior surface of the housing is a first narrow interior wall of the opposite narrow interior walls. The projection extends through a first broad interior wall into the passage, and the absorber element is positioned against the first narrow interior wall.
In accordance with any of the preceding aspects, the waveguide device may be a waveguide termination device, and the second end may be a closed end.
In accordance with any of the preceding aspects, the second end includes a flange radially extending from the elongated housing, the flange being configured to be connected to a transmission line of a waveguide system.
In accordance with any of the preceding aspects, the waveguide device may further comprise a spring connecting the closed end to a first end of the elongated absorber element. A stopper may be positioned at a second end of the elongated absorber element and is configured to exert a force on the first end of the elongated absorber element such that the second end of the elongated absorber is configured to be stopped at the stopper.
According to a second aspect, the disclosure relates to a multi-way waveguide combiner. The combiner comprises one or more waveguide devices as defined in any of the preceding aspects.
According to a third aspect, the disclosure relates to a waveguide system. The waveguide comprises one or more waveguide devices as defined in any of the preceding aspects.
According to a fourth aspect, the disclosure relates to a method of manufacturing a waveguide device. The method comprises: providing an elongated absorber element; providing an elongated housing including a first end and a second end. The first end is a power receiving end. The elongated housing defines a hollow passage. A traversal projection extends from the elongated housing into the passage. The projection and an interior surface of the elongated housing define a space shaped to snugly receive the elongated absorber element. The method also comprises sliding the elongated absorber element into a space defined by the transversal projection and the passage such that the transversal projection exerts a resilient force against the absorber element to urge the absorber element against the interior surface of the housing.
In accordance with any of the preceding aspects, the projection is part of a distal end of a screw extending from the housing into the hollow passage.
In accordance with any of the preceding aspects, providing the elongated housing comprises inserting the screw into an aperture formed on an outer surface of the elongated housing so that the part of the distal end that corresponds to the projection extends into the passage.
In accordance with any of the preceding aspects, the method further comprises connecting an E-bend assembly to the power receiving end of the housing.
In accordance with any of the preceding aspects, the method further comprises attaching at least one cooling system at an exterior surface of the housing.
In accordance with any of the preceding aspects, the elongated housing includes two opposite broad interior walls and two opposite narrow interior walls. The interior surface of the housing is a first narrow interior wall of the two opposite narrow interior walls. The projection extends through a first broad interior wall into the passage. The sliding the elongated absorber element into the passage includes positioning the absorber element against the first narrow interior wall so that it is wedged between the first narrow interior wall and the projection.
All features of exemplary embodiments which are described in this disclosure and are not mutually exclusive can be combined with one another. Elements of one embodiment or aspect can be utilized in the other embodiments/aspects without further mention. These and other aspects of this disclosure will now become apparent to those of ordinary skill in the art upon review of a description of embodiments that follows in conjunction with accompanying drawings.
Reference will now be made, by way of example, to the accompanying drawings which show example embodiments of the present application, and in which:
Similar reference numerals may have been used in different figures to denote similar components.
In the drawings, embodiments are illustrated by way of example. It is to be expressly understood that the description and drawings are only for purposes of illustrating certain embodiments and are an aid for understanding. They are not intended to be a definition of the limits of the invention.
A detailed description of one or more specific embodiments of the present disclosure is provided below along with accompanying Figures that illustrate principles of the invention. The invention is described in connection with such embodiments, but the invention is not limited to any specific embodiment. The scope of the invention is limited only by the claims. Numerous specific details are set forth in the following description in order to provide a thorough understanding of the invention. These details are provided for the purpose of describing non-limiting examples and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in great detail so that the invention is not unnecessarily obscured.
Similar reference numerals may have been used in different figures to denote similar components.
As best see in
In specific practical implementations, the housing 102 may be made of conductive metal, such as for example, but without being limited to, aluminum, copper, brass, bronze, or invar. This is illustrative and is not intended to be limiting. In other possible configuration, the housing 102 may be made of any suitable material that provides a passage to transmit electromagnetic waves.
The first and second absorber elements 118(1), 118(2) positioned within the housing 102 act as loads to enable the impedance of the waveguide termination device 100 to be matched with that of the transmission line of the waveguide circuit and to absorb at least part of the energy of the electromagnetic wave traveling through the passage of the housing 102.
Specific examples of configurations (e.g., shape, orientation, and/or placement) of an example absorber element 118 will now be described with reference to
Specific examples of manners of securing the first and/or second absorber element 118 to the corresponding narrow interior wall 124, using the plurality of projections 108(1)-108(10), will be now described in greater detail with reference to
It should be appreciated that the projection 108(4) is discussed below as a representative of the plurality of projections 108(1)-108(10) for ease of illustration. That is, configurations of the plurality of projections 108 may be identical to that of the projection 108(4). However, it is not intended to be limiting. In other examples, a respective configuration (e.g., shape, material, and/or size) of each projection 108 may be different so long as the projection 108 has the ability to exert a respective resilient force on the absorber element 118. In some implementations (not shown in the Figures), the projection 108(4) may be formed directly on an internal wall of the housing, so that the projection and the housing form a unitary component, using any suitable machining technique to create the projection. The projection may have any suitable shape so that the projection and an interior surface of the elongated house define a space configured to snugly receive the elongated absorber element. It is not intended to be limiting. The integration process to include the projection 108 into the housing 102 may be implemented using any other suitable method known in the art. In addition, although the absorber elements 118 being urged against the corresponding narrow interior wall 124 are depicted in the present disclosure, it is illustrative and not intended to be limiting. In other possible configurations, the absorber elements 118 may instead be urged against the two broad interior walls 122 by projections extending from the narrow interior walls 124.
In some other implementations, the projection 108(4) may be a part of a distal end of a screw extending from the housing into the hollow passage, wherein the screw is inserted through an aperture formed on an outer surface of the elongated housing 102 so that the part of the distal end of the screw corresponding to the projection extends into the passage.
Reference is now made with respect to
In contrast to the use of braising techniques and adhesives, which are prone to cracking and/or breaking under high temperature conditions, by using the projection 180 to the absorber elements 118 against an interior wall of the housing, permanent attachments can be avoided to improve the flexibility of the waveguide termination device without reducing performance (e.g., high power handling capability, low VRSW, broad operation frequency) of the waveguide termination device. For example, physical damages (e.g., broken or cracking) may be prevented because the housing 102 (e.g., the narrow interior walls) can expand more freely without causing impact on their thermal connection with the absorber elements. Furthermore, as the resilient force, rather than any permanent approaches, enables the absorber element 118 to be in contact with the side walls of the housing, the absorber element 118 may be readily replaced with a new absorber element 118 in the case of breakage and/or when an absorber element 118 with different proprieties is desired. In a case where operation frequency or any characteristic of the waveguide termination device is required to change, the waveguide termination device can be easily adapted by substituting the absorber element 118. It is noted that sliding the absorber element 118 into the housing is a simpler process, compared with using adhesives or braising techniques. Hence, hardware costs for operating a waveguide system overall may be reduced.
In addition, as the absorber elements 118 are urged to be in contact with the narrow interior walls 124 of the housing 102, such contact establishes thermal conduction paths that transfer heat from the absorber elements 118 to interior side walls (e.g., the first and second narrow interior walls 124(1), 124(2)) of the housing 102, which may enable absorbed heat to be conducted to the housing 102 more easily.
In the example of
As shown in
In the example of
It is noted that, although the projection 108(4) is illustrated as a part of an example screw 200200′ above, this is only illustrative. By way of another non-limiting example, in one possible configuration, the projection 108(4) may be a part of a screw which does not have a screw head (not shown in the figures). In yet other alternative examples, the projection 108(4) may be a part of a pin (e.g., press fit pin, slide fit pin, or soldered pin) or a solder bracket, etc.
Returning to
Referring back to
In some examples, the waveguide termination device 100 may incorporate a E-bend assembly 110 which is connected to the power receiving end 104 of the housing 102. The E-bend assembly 110 helps to change or distort E-filed of the electromagnetic waves transmitted from the transmission line of the waveguide. By way of non-limiting example, in one alternative possible configuration (not shown in the Figures), the waveguide termination device 100 may include a H-bend assembly, a straight waveguide, or other types of waveguides.
In alternative examples, as shown in
As shown in
In some applications, one or more waveguide termination devices 100 as discussed in the present disclosure may be included in a multi-way waveguide combiner or other waveguide circuit, in order to achieve a desired characteristic (e.g., broad operation frequency and/or low VSRW) for the waveguide combiner or circuit. For example, an 8-way waveguide combiner may include seven waveguide termination devices (e.g., the waveguide termination device 100 as described in the present disclosure) to absorb electromagnetic waves transmitted from their respective combiner waveguide port.
At step 402, an elongated absorber element is provided. The elongated absorber element may be the first or second elongated absorb element 118(1) or 118(2) as discussed above.
At step 404, an elongated housing is provided. Taking the elongated housing 102 as shown in
In alternative examples, the five projections 108(1)-108(5) are manufactured separately from the housing 102, and then assembled, such as inserted, with the housing 102 when necessary. For instance, each projection 108 (e.g., the projection 108(4)) is part of a screw (e.g., the screw 200 as shown in
At step 406, the absorber element is slid into the passage in the space defined by the projection and the interior surface of the passage. Once the five projections 108(1)-108(5) are manufactured or assembled to extend into the passage of the housing 102, the first absorber element 118(1) is then slid into a space defined by the first narrow interior wall 124(1), the first and second broad interior wall 122(1), 122(2), and the five projections 108(1)-108(5). Therefore, each of the five projections 118(1)-118(5) exerts a corresponding resilient force on the first absorber element 118(1) to urge the first absorber element 118(1) against the first narrow interior wall 124(1) of the housing 102.
At optional step 408, an E-bend assembly is connected to a power receiving end of the housing. For instance, standard brazing techniques or any suitable techniques may be utilized to connect the E-bend assembly to the power receiving end of the housing.
At step 410, alternatively, at least one cooling system is attached at an exterior surface of the housing. An approach for the attaching may include adhesive, brazing, or any suitable manners. In some applications, the cooling system may be replaced with one or more heat sink. It should be appreciated that although the at least one cooling system or heat sink may be used in high power applications, in low power applications, the cooling system and/or heat sink may be omitted.
In some examples, the steps 408 and 410 may be performed before, after, or between the steps 402-406.
The method of sliding the absorber element into a space defined by the projection(s) and the interior surface of the elongated housing such that the absorber element can be snugly received by the space. Thus, the absorber element can be urged against interior narrow walls of the housing firmly without using any permanent attaching techniques. Thus, physical damages that would otherwise be caused by thermal expansion of the housing when absorber elements are secured by an adhesive of by brazing may be avoided using the approach described herein. Furthermore, flexibility of substituting the absorber element may be improved significantly. It is to be appreciated that any suitable absorber element 118 may be used in practical implementations to achieve a desired characteristic of the waveguide termination device, for example including a desired operation frequency of the electromagnetic waves, a desired VSWR, or a desired size of the housing. Such a method enables a waveguide termination device to be manufactured, constructed, and/or assembled with relative simplicity and flexibility.
It should be understood that although specific materials, shape, and/or size are discussed above with respect to each of the housing 102, the absorber elements 118, and/or the projections 108, in some other configurations, other suitable material, shape, and/or size may be utilized in the configurations discussed in
Although the present disclosure describes methods and processes with steps in a certain order, one or more steps of the methods and processes may be omitted or altered as appropriate. One or more steps may take place in an order other than that in which they are described, as appropriate.
The present disclosure may be embodied in other specific forms without departing from the subject matter of the claims. The described example embodiments are to be considered in all respects as being only illustrative and not restrictive. Selected features from one or more of the above-described embodiments may be combined to create alternative embodiments not explicitly described, features suitable for such combinations being understood within the scope of this disclosure.
All values and sub-ranges within disclosed ranges are also disclosed. Also, although the systems, devices and processes disclosed and shown herein may comprise a specific number of elements/components, the systems, devices and assemblies could be modified to include additional or fewer of such elements/components. For example, although any of the elements/components disclosed may be referenced as being singular, the embodiments disclosed herein could be modified to include a plurality of such elements/components. The subject matter described herein intends to cover and embrace all suitable changes in technology.
In some embodiments, any feature of any embodiment described herein may be used in combination with any feature of any other embodiment described herein.
Certain additional elements that may be needed for operation of certain embodiments have not been described or illustrated as they are assumed to be within the purview of those of ordinary skill in the art. Moreover, certain embodiments may be free of, may lack and/or may function without any element that is not specifically disclosed herein.
It will be understood by those of skill in the art that throughout the present specification, the term “a” used before a term encompasses embodiments containing one or more to what the term refers. It will also be understood by those of skill in the art that throughout the present specification, the term “comprising”, which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, un-recited elements or method steps. As used in the present disclosure, the terms “around”, “about” or “approximately” shall generally mean within the error margin generally accepted in the art. Hence, numerical quantities given herein generally include such error margin such that the terms “around”, “about” or “approximately” can be inferred if not expressly stated.
In describing embodiments, specific terminology has been resorted to for the sake of description, but this is not intended to be limited to the specific terms so selected, and it is understood that each specific term comprises all equivalents. In case of any discrepancy, inconsistency, or other difference between terms used herein and terms used in any document incorporated by reference herein, meanings of the terms used herein are to prevail and be used.
References cited throughout the specification are hereby incorporated by reference in their entirety for all purposes.
Although various embodiments of the disclosure have been described and illustrated, it will be apparent to those skilled in the art in light of the present description that numerous modifications and variations can be made. The scope of the invention is defined more particularly in the appended claims.
