The disclosure relates to a stub tuner inserted into a waveguide tube that transmits high frequency waves.
A waveguide tube is used as a radio wave transmission path in a device using high frequency waves (e.g., microwaves), such as a weather radar. At a connection portion between the waveguide tube and another transmission path or a connection portion between the waveguide tube and an apparatus, a transmission path non-conformity may occur intentionally or unintentionally. Such non-conformity is referred to as a mismatch. Since a mismatch adversely affects the transmission path, it is necessary to perform impedance adjustment to suppress the reflection or leakage of high frequency waves from a mismatch part, and a stub tuner is provided in the waveguide tube.
For example, while not a weather radar, Patent Document 1 (Japanese Laid-open No. H08078914) discloses a stub tuner slidably movable in a direction orthogonal to a tube axial direction of a waveguide tube.
While not a weather radar, FIG. 2 of Patent Document 2 (WO2016/135899) discloses a short plunger (106) disposed in a rectangular waveguide tube (101). A gap is shown between the short plunger (106) and the rectangular waveguide tube (101), and a possibility that radio waves may leak from the axial direction end of the waveguide tube through such gap is considered.
While not a weather radar, Patent Document 3 (Japanese Laid-open No. 2010-168684) discloses a movable plunger 34 having a conductive surface for reflecting microwaves. A gap is shown between the movable plunger 34 and a waveguide tube, and a possibility that radio waves may leak from the axial direction end of the waveguide tube through such gap is considered.
A stub tuner according to the disclosure may include a first conductor and a conductor shaft. The first conductor is inserted from an opening of a waveguide tube transmitting high frequency waves to a tube axial direction inner side and includes a first shape and a second shape. The first shape is a plate shape extending in a direction intersecting with the tube axial direction in the waveguide tube. The second shape is a plate shape extending along the tube axial direction from a tube axial direction outer end of the first shape toward a tube axial direction outer side. An outer circumferential surface of the second shape is separated from an inner surface of the waveguide tube, and an electrical length along the tube axial direction on the outer circumferential surface of the second shape is ¼ of a wavelength of the high frequency waves. The conductor shaft has a rod shape, is electrically connected to the waveguide tube, supports the first conductor, and extends in the tube axial direction.
According to an embodiment, in the first conductor, a distance between an inner circumferential surface of the second shape and an outer circumferential surface of the conductor shaft may be greater than a distance between the outer circumferential surface of the second shape and the inner surface of the waveguide tube.
According to an embodiment, the stub tuner may include a support member provided at the conductor shaft on an opening side of the waveguide tube with respect to the first conductor, and contacting an inner surface of the waveguide tube to pass through the conductor shaft to support the first conductor.
According to an embodiment, in a cross-section where the first conductor is present, the conductor shaft may be located at a center of a pair of the second shapes. The support member may be formed by a conductor and electrically connected to the conductor tube. In the first conductor and the conductor shaft, an electrical length along component surfaces from an intersection point P3 with the support member on an outer circumferential surface of the conductor shaft to a tube axial direction outer end P6 of an inner circumferential surface of the second shape through an intersection point P4 with a tube axial direction outer side surface of the first shape on an outer circumferential surface of the conductor shaft and an intersection point P5 with the inner circumferential surface of the second shape on the tube axial direction outer side surface of the first shape may be ¾ of the wavelength of the high frequency waves.
According to an embodiment, an insulating layer may be provided on the outer circumferential surface of the second shape.
According to an embodiment, the waveguide tube may be a rectangular waveguide tube in which a tube cross-sectional surface has long sides and short sides. The second shape may be a shape of a pair of plates respectively extending from a tube axial direction outer end of the first shape toward the opening along the tube axial direction, and the shape of the pair of plates may face at least a portion of the inner surface on the long sides of the waveguide tube.
According to an embodiment, in a cross-section passing through central portions of the long sides and a tube axis, the first conductor may be in a U shape.
According to an embodiment, the waveguide tube may be a circular waveguide tube in which a tube cross-sectional surface is circular, and the second shape may be formed to be line symmetric with the conductor shaft as an axis of symmetry.
The disclosure provides a stub tuner which prevents leakage of radio waves from an opening in a tube axial direction end portion of a waveguide tube.
In the following, a stub tuner according to the first embodiment of the disclosure is described with reference to the drawings.
As shown in
The stub tuner 2 is configured to be slidably movable in a tube axial direction AD of the waveguide tube 1. Accordingly, as shown in
As shown in
As shown in
As shown in
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As shown in
In the embodiment, in the cross-section (see
The stub tuner 2 can be assembled as shown in
[Modified Example of First Embodiment]
A stub tuner of a second embodiment will be described. Components same as those of the first embodiment are labeled with the same reference symbols, and the descriptions thereof will be omitted. As shown in
According to the above, in the first and second embodiments shown in
In this way, since the outer circumferential surface 22a of the second shape (22, 122) is separated from the inner surface 1b of the waveguide tube (1, 101), the transmission path can be considered as equivalent to the transmission path T1 with an open end. In addition, since the electrical length EL2 along the tube axial direction AD on the outer circumferential surface 22a of the second end (22, 122) is ¼ of the wavelength λ of the high frequency waves, the oscillating electric field E generated in the waveguide tube (1, 101) becomes an antinode at the axial direction outer end P2 on the outer circumferential surface 22a of the second shape (22, 122). The oscillating electric field E generated in the waveguide tube (1, 101) becomes a node at the axial direction inner end P1 on the outer circumferential surface 22a of the second shape (22, 122). Since the node portion of the oscillating electric field E is arranged at the inlet of the gap between the second shape (22, 122) and the inner surface 1b of the waveguide tube (1, 101), the radio waves entering between the second shape (22, 122) and the inner surface of the waveguide tube (1, 101) can be significantly suppressed, and radio wave leakage as well as discharge between the second shape (22, 122) and the waveguide tube (1, 101) can be prevented.
In addition, since the second shape (22, 122) is separated from the inner surface 1b of the waveguide tube (1, 101), the outer diameter of the first conductor (20, 120) is smaller than the inner diameter of the waveguide tube, and, compared with a configuration in which the inner diameter of the waveguide tube and the outer diameter of the first conductor are the same, the first conductor (20, 120) can be moved with a smaller operation force during position adjustment. Moreover, the generation of metal powder due to contact between the first conductor (20, 120) and the waveguide tube (1, 101) can be reduced or prevented, and it is possible to suppress a failure.
Although the disclosure is not particularly limited, according to the first and second embodiments shown in
According to such configuration, by reducing the electric field between the inner circumferential surface 22b of the second shape (22, 122) and the outer circumferential surface 23a of the conductor shaft 23, the electrical field difference with respect to the inner surface 1b of the waveguide tube (1, 101), which occurs on the outer circumferential surface 22a of the second shape (22, 122), acts strongly, and the performance as a short stub is facilitated. In addition, it is possible to suppress the occurrence of an anomaly that discharge occurs between the inner circumferential surface 22b of the second shape (22, 122) and the outer circumferential surface 23a of the conductor shaft 23.
Although the disclosure is not particularly limited, according to the first and second embodiments shown in
According to the configuration, since the position of the first conductor (20, 120) in the tube axial direction AD can be changed while the support member (24, 124) is brought into contact with the inner surface 1b of the waveguide tube (1, 101), it is possible facilitate the operability.
Although the disclosure is not particularly limited, according to the first and second embodiments shown in
According to the configuration, since the support member (24, 124) is a conductor and electrically connected to the waveguide tube (1, 101), the oscillating electric field E becomes a node at the intersection point P3. With the transmission path T2 formed by the metal skin on the inner circumferential side of the second shape from the intersection point P3 to the intersection point P6 via the intersection points P4 and P5, the oscillating electric field E becomes an antinode at the tube axial direction outer end P6 of the inner circumferential surface 22b of the second shape (22, 122). Meanwhile, the electrical length EL2 along the tube axial direction AD on the outer circumferential surface 22a of the second shape (22, 122) is ¼ of the wavelength λ of the high frequency waves, and, with the transmission path T1 formed between the outer circumferential surface 22a of the second shape (22, 122) and the inner surface 1b of the waveguide tube (1, 101), the oscillating electric field E at the tube axial direction outer end P2 of the outer circumferential surface of the second shape becomes an antinode. By doing so, in each of the transmission paths (T1, T2) formed on the outer circumferential side and the inner circumferential side of the second shape (22, 122), the oscillating electric field E becomes an antinode at the tube axial direction outer end (P2, P6) of the second shape. As a result, the oscillating electric field E becoming a node in the tube axial direction inner end P1 on the outer circumferential surface 22a of the second shape (22, 122) can be facilitated, and it is possible to facilitate a radio wave shielding effect.
Although the disclosure is not particularly limited, according to the embodiment shown in
With the configuration, even if the second shape 22 mechanically contact the inner surface 1b of the waveguide tube 1 when the first conductor 20 is inserted into the waveguide tube 1, it is possible to suppress collapse of the electrical length EL2, as the second shape 22 and the waveguide tube 1 are not in electric contact due to the insulating layer 3.
Although the disclosure is not particularly limited, according to the first embodiment shown in
According to the configuration, it is possible to suitably suppress leakage of the high frequency waves in the rectangular waveguide tube 1. In addition, it is not required that the entire inner surface on the long sides 11 faces second shape 2, and the design and adjustment are simplified.
Although the disclosure is not particularly limited, according to the first embodiment shown in
According to the configuration, since the portion passing through the centers 11s of the long sides 11 and the tube axis A1 in the rectangular waveguide tube 1 is a portion with the maximum electric field, it is possible to reliably exhibit the effects.
Although the disclosure is not particularly limited, according to the second embodiment shown in
According to the configuration, in the circular waveguide tube 101, the electric field is at the maximum along any tube axial direction passing through the tube axis A1. Therefore, it is possible to reliably exhibit the effects.
Although the embodiments of the disclosure have been described above based on the drawings, it should be considered that the specific configurations are not limited to these embodiments. The scope of the disclosure is indicated not only by the description of the above embodiments but also by the scope of claims, and includes all modifications within the meaning and scope equivalent to the scope of claims.
It is possible to adopt the structure adopted in each of the above embodiments in any other embodiment.
The specific configuration of each part is not limited to the above embodiments, and various modifications are possible without departing from the scope of the disclosure.
It is to be understood that not necessarily all objects or advantages may be achieved in accordance with any particular embodiment described herein. Thus, for example, those skilled in the art will recognize that certain embodiments may be configured to operate in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
All of the processes described herein may be embodied in, and fully automated via, software code modules executed by a computing system that includes one or more computers or processors. The code modules may be stored in any type of non-transitory computer-readable medium or other computer storage device. Some or all the methods may be embodied in specialized computer hardware.
Many other variations than those described herein will be apparent from this disclosure. For example, depending on the embodiment, certain acts, events, or functions of any of the algorithms described herein can be performed in a different sequence, can be added, merged, or left out altogether (e.g., not all described acts or events are necessary for the practice of the algorithms). Moreover, in certain embodiments, acts or events can be performed concurrently, e.g., through multi-threaded processing, interrupt processing, or multiple processors or processor cores or on other parallel architectures, rather than sequentially. In addition, different tasks or processes can be performed by different machines and/or computing systems that can function together.
The various illustrative logical blocks and modules described in connection with the embodiments disclosed herein can be implemented or performed by a machine, such as a processor. A processor can be a microprocessor, but in the alternative, the processor can be a controller, microcontroller, or state machine, combinations of the same, or the like. A processor can include electrical circuitry configured to process computer-executable instructions. In another embodiment, a processor includes an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable device that performs logic operations without processing computer-executable instructions. A processor can also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor (DSP) and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Although described herein primarily with respect to digital technology, a processor may also include primarily analog components. For example, some or all of the signal processing algorithms described herein may be implemented in analog circuitry or mixed analog and digital circuitry. A computing environment can include any type of computer system, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a device controller, or a computational engine within an appliance, to name a few.
Conditional language such as, among others, “can,” “could,” “might” or “may,” unless specifically stated otherwise, are otherwise understood within the context as used in general to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment.
Disjunctive language such as the phrase “at least one of X, Y, or Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present.
Any process descriptions, elements or blocks in the flow diagrams described herein and/or depicted in the attached figures should be understood as potentially representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or elements in the process. Alternate implementations are included within the scope of the embodiments described herein in which elements or functions may be deleted, executed out of order from that shown, or discussed, including substantially concurrently or in reverse order, depending on the functionality involved as would be understood by those skilled in the art.
Unless otherwise explicitly stated, articles such as “a” or “an” should generally be interpreted to include one or more described items. Accordingly, phrases such as “a device configured to” are intended to include one or more recited devices. Such one or more recited devices can also be collectively configured to carry out the stated recitations. For example, “a processor configured to carry out recitations A, B and C” can include a first processor configured to carry out recitation A working in conjunction with a second processor configured to carry out recitations B and C. The same holds true for the use of definite articles used to introduce embodiment recitations. In addition, even if a specific number of an introduced embodiment recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations).
It will be understood by those within the art that, in general, terms used herein, are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.).
For expository purposes, the term “horizontal” as used herein is defined as a plane parallel to the plane or surface of the floor of the area in which the system being described is used or the method being described is performed, regardless of its orientation. The term “floor” can be interchanged with the term “ground” or “water surface”. The term “vertical” refers to a direction perpendicular to the horizontal as just defined. Terms such as “above,” “below,” “bottom,” “top,” “side,” “higher,” “lower,” “upper,” “over,” and “under,” are defined with respect to the horizontal plane.
As used herein, the terms “attached,” “connected,” “mated,” and other such relational terms should be construed, unless otherwise noted, to include removable, moveable, fixed, adjustable, and/or releasable connections or attachments. The connections/attachments can include direct connections and/or connections having intermediate structure between the two components discussed.
Numbers preceded by a term such as “approximately”, “about”, and “substantially” as used herein include the recited numbers, and also represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, and “substantially” may refer to an amount that is within less than 10% of the stated amount. Features of embodiments disclosed herein preceded by a term such as “approximately”, “about”, and “substantially” as used herein represent the feature with some variability that still performs a desired function or achieves a desired result for that feature.
It should be emphasized that many variations and modifications may be made to the above-described embodiments, the elements of which are to be understood as being among other acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.
Number | Date | Country | Kind |
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2020-173720 | Oct 2020 | JP | national |
The present application is a continuation of PCT/JP2021/033884, filed on Sep. 15, 2021, and is related to and claims priority from Japanese patent application no. 2020-173720, filed on Oct. 15, 2020. The entire contents of the aforementioned applications are hereby incorporated by reference herein.
Number | Date | Country | |
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Parent | PCT/JP2021/033884 | Sep 2021 | US |
Child | 18173750 | US |