Radiating element, waveguide antenna, and method for manufacturing a radiating element

Abstract

The radiating element includes a first hollow tube section into which electromagnetic waves can be coupled, the first hollow tube section having a first rectangular cross section, a short side extending parallel to a first axis, a long side extending parallel to a second axis, and the first hollow tube section extending along a third axis, the first, second, and third axes being orthogonal to each other in pairs. The radiating element further includes a second hollow tube section having a second rectangular cross section, a short side extending parallel to the third axis, and a long side extending parallel to the first axis, and the second hollow tube section extending along the second axis. A first dimension of the short side in a first region of the second hollow tube section is smaller than a second dimension of the short side in a second region of the second hollow tube section. Electromagnetic waves can be fed from the first hollow tube section to the second hollow tube section through a slot in the first region and can be emitted through an open end of the second region of the second hollow tube section.

Description

Technical Field

[0001] The present invention relates to a radiating element for a waveguide antenna, a waveguide antenna, and a method for manufacturing the radiating element.

Background Art

[0002] In a hollow tube or waveguide, electromagnetic energy is carried in a metallic hollow space. The hollow tube may be part of a waveguide antenna. In the simplest case, slots are formed in the hollow tube, and the slots constitute an interface between the internal region of the hollow tube and free space, i.e., serve as radiating elements. This slot does not need to extend completely parallel to the flow of electromagnetic waves traveling through the hollow tube.

[0003] Since a single slot has only low directivity, a hollow tube antenna usually has a plurality of slots forming an antenna array. The simplest way to form a hollow tube antenna array is to arrange slots along the long side of the rectangular cross-section of the hollow tube, keeping a spacing of half a wavelength, and creating a zigzag structure relative to the center of the hollow tube. With the zigzag structure, all slots radiate in the same phase.

[0004] When such a hollow tube antenna array is continuously produced in a cost-effective manner, two metal parts can be fabricated and then joined together. At this time, the hollow tube passage can be arranged vertically, and the narrow side is kept open for radiation. The joining of both parts is performed parallel to the narrow side of the hollow tube, so that the flow through the hollow tube is not disturbed. It is even not necessary for both metal parts to have a galvanic contact, thereby hardly affecting the wave guiding performance of the hollow tube.

[0005] To enable the necessary spacing between radiating elements, U.S. Patent Application Publication No. 2020 / 203841 proposes a central-feed, open-circuit hollow tube antenna array, in which the feed waveguide is coupled to elements formed by two openings. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 203841 [Overview of the project]

[0007] The present invention provides a radiating element for a waveguide antenna, a waveguide antenna, and a method for manufacturing a radiating element for a waveguide antenna having the constituent elements of an independent claim.

[0008] Preferred embodiments are the subject of each dependent claim.

[0009] Accordingly, in a first aspect, the present invention relates to a radiating element for a waveguide antenna. The radiating element includes a first hollow tube section that can input-couple electromagnetic waves, the first hollow tube section having a first rectangular cross-section, the short side of the first rectangular cross-section extending parallel to a first axis, the long side of the first rectangular cross-section extending parallel to a second axis, the first hollow tube section extending along a third axis, and the first to third axes being orthogonal to each other in pairs. The radiating element further includes a second hollow tube section having a second rectangular cross-section, the short side of the second rectangular cross-section extending parallel to a third axis, the long side of the second rectangular cross-section extending parallel to a first axis, and the second hollow tube section extending along a second axis. The first dimension of the shorter side of the second rectangular cross section is smaller in the first region of the second hollow tube area than the second dimension of the shorter side of the second rectangular cross section in the second region of the second hollow tube area. Electromagnetic waves can be fed from the first hollow tube area to the second hollow tube area through a slot in the first region of the second hollow tube area and can be transmitted through the open end of the second region of the second hollow tube area.

[0010] In a second aspect, the present invention relates to a waveguide antenna having a plurality of radiating elements based on the first aspect and an output splitter configured to feed electromagnetic waves into a first hollow tube area of ​​each of the radiating elements.

[0011] In a third aspect, the present invention relates to a method for manufacturing a radiating element for a waveguide antenna. A first hollow tube section is configured to be input-coupled to electromagnetic waves, the first hollow tube section having a first rectangular cross section, the short side of the first rectangular cross section extending parallel to a first axis, the long side of the first rectangular cross section extending parallel to a second axis, the first hollow tube section extending along a third axis, and the first to third axes being orthogonal to each other in pairs. A second hollow tube section is configured, the second hollow tube section having a second rectangular cross section, the short side of the second rectangular cross section extending parallel to a third axis, the long side of the second rectangular cross section extending parallel to a first axis, and the second hollow tube section extending along a second axis. The first dimension of the shorter side of the second rectangular cross-section in the first region of the second hollow tube area is smaller than the second dimension of the shorter side of the second rectangular cross-section in the second region of the second hollow tube area. Electromagnetic waves can be fed from the first hollow tube area to the second hollow tube area through a slot in the first region of the second hollow tube area, and can be transmitted through the open end of the second region of the second hollow tube area. [Effects of the Invention]

[0012] The present invention provides an independent radiating element that can be supplied by an output splitter and subsequently emits electromagnetic radiation.

[0013] The radiating element includes a first hollow tube section that serves to feed electromagnetic radiation into a second hollow tube section. The feed is performed laterally into a slot in the first region of the second hollow tube section, that is, perpendicular to the radiating aperture formed by the opening of the second hollow tube section. This allows for a compact waveguide antenna structure, as multiple radiating elements can be arranged adjacent to each other at small intervals.

[0014] The radiating element is compactly configured, and the difference in the dimensions of the shorter sides between the first and second regions allows for impedance transformation in the vertical dimension, enabling a wide range of impedance matching from the vertical power splitter to the radiating element.

[0015] In this case, the first and second dimensions of the shorter side of the second rectangular cross-section are subject to parameters and can be appropriately selected for impedance matching in the frequency domain to which electromagnetic radiation is applied. The dimensions of the longer side of the second rectangular cross-section and the dimensions of the extension of the second hollow tube section along the second axis are subject to yet another parameter.

[0016] Here, "dimensions" are understood to refer to the respective lengths.

[0017] In another embodiment of the radiating element, the second hollow tube region has a third region between the first region of the second hollow tube region and the second region of the second hollow tube region, where the dimension of the shorter side of the second rectangular cross-section in the third region increases linearly from the first dimension to the second dimension. This linear increase, which can be expressed in terms of angle, becomes yet another parameter that can be used for impedance matching.

[0018] In another embodiment of the radiating element, the three sides of the second hollow tube section are planar. The second hollow tube section may be configured, for example, in an L-shape.

[0019] In another embodiment of the radiating element, the slot in the first region of the second hollow tube region is offset along a third axis with respect to the center of the second hollow tube region. The dimension of this offset conforms to yet another parameter for impedance matching.

[0020] In another embodiment of the radiating element, the dimension of the long side of the second rectangular cross-section is greater than or equal to half of the wavelength of the electromagnetic wave and less than or equal to three-quarters of the wavelength of the electromagnetic wave for a given application field of the radiating element.

[0021] In another embodiment of the radiating element, the extension of the second region of the second hollow tube region along the second axis is less than or equal to one-quarter of the wavelength of the electromagnetic wave.

[0022] In another embodiment of the method for manufacturing a radiating element for a waveguide antenna, the second hollow tube region has a third region between the first region of the second hollow tube region and the second region of the second hollow tube region, and the dimension of the short side of the second rectangular cross-section in the third region linearly increases from the first dimension to the second dimension.

[0023] In another embodiment of the method for manufacturing a radiating element for a waveguide antenna, three sides of the second hollow tube region are planar.

[0024] Other advantages, components, and specific matters of the present invention will become apparent from the following description in which various embodiments are specifically described with reference to the drawings.

Brief Description of the Drawings

[0025] The drawings show the following. [Figure 1] FIG. 1 is a schematic cross-sectional view showing a waveguide antenna having a radiating element according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic view showing a radiating element according to an embodiment of the present invention obliquely from above. [Figure 3]FIG. 3 is another schematic view showing the radiation element shown in FIG. 2 from an obliquely upward direction. [Figure 4] FIG. 4 is a schematic view showing the radiation element shown in FIGS. 2 and 3 from an obliquely downward direction. [Figure 5] FIG. 5 is a schematic cross-sectional view showing the radiation element shown in FIGS. 2 to 4. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a radiation element based on another embodiment of the present invention. [Figure 7] FIG. 7 is a schematic exploded view showing a radiation element based on another embodiment of the present invention. [Figure 8] FIG. 8 is a flowchart of a method for manufacturing a radiation element for a waveguide antenna based on an embodiment of the present invention.

[0026] In any of the drawings, the same elements or functions are denoted by the same reference numerals in the same elements and devices. The numbers of the method steps are for indicating the outline and generally do not imply a specific chronological order. In particular, a plurality of method steps can also be executed simultaneously.

Embodiments for Carrying Out the Invention

[0027] FIG. 1 shows a schematic cross-sectional view of a waveguide antenna 10 having an output splitting device 8 and four radiation elements 1a - 1d. The output splitting device 8 includes an input portion 81 to which an electromagnetic signal is supplied. The output of the electromagnetic signal is split by the output splitting device 8, and the four radiation elements 1a - 1d receive the supply of their respective electromagnetic signals. At this time, the amplitude and phase relationship for each of the individual radiation elements 1a - 1d can be adjusted by the structure and dimensions of the output splitting device 8.

[0028] The present invention is not limited to a specific number of radiation elements 1a - 1d.

[0029] Figure 2 shows a schematic diagram of the radiating element 1 from an oblique angle above, suggesting a hollow tube. Figure 3 shows another schematic diagram of the radiating element 1 shown in Figure 2, suggesting a housing. Figure 4 shows the schematic diagram of the radiating element 1 shown in Figures 2 and 3 from an oblique angle below, also suggesting a hollow tube.

[0030] The radiating element 1 includes a first hollow tube region 2 to which electromagnetic waves can be input-coupled. The first hollow tube region is configured as a rectangular parallelepiped, that is, it has a fixed first rectangular cross-section, the short side of the first rectangular cross-section extending parallel to the first axis X, and the long side of the first rectangular cross-section extending parallel to the second axis Z. The first hollow tube region extends along a third axis Y. The first to third axes X, Y, and Z are in pairs and are orthogonal to each other.

[0031] The radiating element 1 further includes second hollow tube regions 3 and 4, which have a second rectangular cross-section. The short side of the second rectangular cross-section is parallel to the third axis Y. The long side of the second rectangular cross-section is parallel to the first axis X. The second hollow tube regions 3 and 4 extend along the second axis Z. The second rectangular cross-section changes along the extension of the second hollow tube regions 3 and 4 along the second axis Z. In the first region 3, the short side of the second rectangular cross-section has a constant first dimension (width) that is smaller than a constant second dimension of the short side of the second rectangular cross-section in the second region 4 of the second hollow tube regions 3 and 4.

[0032] The sides of the second hollow pipe sections 3 and 4 are planar; that is, the second hollow pipe sections 3 and 4 are configured in an L-shape.

[0033] The first region 3 of the second hollow tube area 3,4 has a slot corresponding to the first rectangular cross-section that extends along the second axis Z. Electromagnetic waves can be fed from the first hollow tube area 2 to the second hollow tube area 3,4 through the slot in the first region 3 of the second hollow tube area 3,4. Subsequently, electromagnetic radiation is emitted through the open end of the second region 4 of the second hollow tube area 3,4.

[0034] The slot in the first region 3 of the second hollow pipe area 3,4 is offset along the third axis X with respect to the center of the second hollow pipe area 3,4. This slot is located at a distance Inp from one side of the first region 3 of the second hollow pipe area 3,4.

[0035] The longer side of the second rectangular cross-section of the second hollow tube section 3,4 has a length La.

[0036] Figure 5 shows a schematic cross-sectional view of the radiating element 1 shown in Figures 2 to 4. The second hollow tube regions 3 and 4 have a first dimension W1 in the first region 3 and a second dimension W2 in the second region 4 with respect to the shorter side of the second cross-section. The angle α of the protruding portion of the second region 4 of the second hollow tube regions 3 and 4 is 90 degrees. Furthermore, the second region 4 of the second hollow tube regions 3 and 4 has a length L1 along the second axis Z.

[0037] Figure 6 shows a schematic diagram of the radiating element 1', where the angle α is greater than 90 degrees. That is, the second hollow tube regions 3, 4, and 7 have a third region 7 between the first region 3 of the second hollow tube region 3, 4, and 7 and the second region 4 of the second hollow tube region 3, 4, and 7, and the dimension of the shorter side of the second rectangular cross-section in the third region increases linearly from the first dimension W1 to the second dimension W2.

[0038] Thus, in total, there are six parameters W1, W2, L1, La, Inp, and α, which can be selected for impedance matching in the frequency domain to which electromagnetic radiation is applied.

[0039] In this case, the dimension La of the longer side of the second rectangular cross-section is greater than or equal to half the wavelength λ0 of the electromagnetic wave, and less than or equal to three-quarters of the wavelength λ0 of the electromagnetic wave: λ0 / 2 ≤ La ≤ 3λ0 / 4.

[0040] The extension L1 of the second region 4 of the second hollow tube area along the second axis Z is less than or equal to one-quarter of the wavelength λ0 of the electromagnetic wave: L1 ≤ λ0 / 4

[0041] Furthermore, the angle α is greater than or equal to 90 degrees.

[0042] Figure 7 shows a schematic exploded view of the radiating element 1''. The housing of the radiating element 1'' includes a first part 6 and a second part 7, which are coupled centrally and parallel to each other with respect to a first axis X and a third axis Y. This coupling may not be achieved by a galvanic connection.

[0043] Figure 8 shows a flowchart illustrating the method for manufacturing the radiating elements for a waveguide antenna, particularly the radiating elements 1a-1d;1;1';1'' described above.

[0044] In step S1 of the method, a first hollow tube section 2 is configured to which electromagnetic waves can be input coupled, the first hollow tube section 2 has a first rectangular cross-section, the short side of the first rectangular cross-section extends parallel to the first axis X, the long side of the first rectangular cross-section extends parallel to the second axis Z, the first hollow tube section extends along the third axis Y, and the first to third axes X, Y, and Z are orthogonal to each other in pairs.

[0045] In step S2, the second hollow tube areas 3, 4, and 7 are formed, each having a second rectangular cross-section, the shorter side of which extends parallel to the third axis Y, the longer side of which extends parallel to the first axis X, and the second hollow tube areas 3, 4, and 7 extend along the second axis Z. The first dimension W1 of the shorter side of the second rectangular cross-section in the first region 3 of the second hollow tube areas 3, 4, and 7 is smaller than the second dimension W2 of the shorter side of the second rectangular cross-section in the second region 4 of the second hollow tube areas 3, 4, and 7. Electromagnetic waves can be fed from the first hollow tube area 2 to the second hollow tube areas 3, 4, and 7 through a slot in the first region 3 of the second hollow tube areas 3, 4, and 7, and can be transmitted through the open end of the second region 4 of the second hollow tube areas 3, 4, and 7.

[0046] The second hollow pipe sections 3, 4, and 7 may have a third section 7 between the first section 3 of the second hollow pipe section 3, 4, and 7 and the second section 4 of the second hollow pipe section 3, 4, and 7, where the dimension of the shorter side of the second rectangular section in the third section 7 increases linearly from the first dimension W1 to the second dimension W2.

Claims

1. In the radiating element (1a-1d; 1; 1'; 1") for the waveguide antenna (10), It has a first hollow tube region (2) to which electromagnetic waves can be input coupled, the first hollow tube region (2) has a first rectangular cross-section, the short side of the first rectangular cross-section extends parallel to a first axis (X), the long side of the first rectangular cross-section extends parallel to a second axis (Z), the first hollow tube region (2) extends along a third axis (Y), and the first to third axes (X, Y, Z) are perpendicular to each other in pairs. It has a second hollow tube section (3, 4), the second hollow tube section (3, 4) has a second rectangular cross-section, the short side of the second rectangular cross-section extends parallel to the third axis (Y), the long side of the second rectangular cross-section extends parallel to the first axis (X), and the second hollow tube section (3, 4) extends along the second axis (Z), The first dimension (W1) of the shorter side of the second rectangular cross-section in the first region (3) of the second hollow pipe area (3, 4) is smaller in all locations than the second dimension (W2) of the shorter side of the second rectangular cross-section in the second region (4) of the second hollow pipe area (3, 4). Electromagnetic waves can be fed from the first hollow tube area (2) to the second hollow tube area (3, 4) through a slot located within the range of the first region (3) of the second hollow tube area (3, 4), and can be transmitted through the open end of the second region (4) of the second hollow tube area (3, 4). Radiation element (1a-1d; 1; 1'; 1'').

2. The radiating element (1a-1d; 1; 1'; 1") according to claim 1, wherein the second hollow tube region (3, 4) has a third region (7) between the first region (4) of the second hollow tube region (3, 4) and the second region (3) of the second hollow tube region (3, 4), and the dimension of the shorter side of the second rectangular cross-section in the third region (7) increases linearly from the first dimension (W1) to the second dimension (W2).

3. The radiating element (1a-1d; 1; 1'; 1") according to claim 1, wherein the three sides of the second hollow tube region (3, 4) are planar.

4. The radiating element (1a-1d; 1; 1'; 1") according to claim 1, wherein the slot in the first region (3) of the second hollow tube region (3, 4) is offset along the third axis (X) with respect to the center of the second hollow tube region (3, 4).

5. The radiating element (1a-1d; 1; 1'; 1") according to claim 1, wherein the dimension (La) of the long side of the second rectangular cross-section is greater than or equal to half the wavelength of the electromagnetic wave, and less than or equal to three-quarters of the wavelength of the electromagnetic wave.

6. The radiating element (1a-1d; 1; 1'; 1") according to claim 1, wherein the extension (L1) of the second region (4) of the second hollow tube region (3, 4) along the second axis (Z) is less than or equal to one-quarter of the wavelength of the electromagnetic wave.

7. In the waveguide antenna (10) (1a-1d; 1; 1'; 1"), A plurality of radiating elements (1a-1d; 1; 1'; 1") according to claim 1, An output splitter configured to feed electromagnetic waves to each of the first hollow tube sections (2) of the radiating elements (1a-1d; 1; 1'; 1"), A waveguide antenna having the following characteristics.

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