Radiating element, waveguide antenna, and method for manufacturing a radiating element - Patents.com

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 technology]

[0002] A hollow tube, or waveguide, carries electromagnetic energy within a hollow space in a metal. The hollow tube can be part of a waveguide antenna; in the simplest case, a slot is formed in the hollow tube, which forms the interface between the interior region of the hollow tube and free space, i.e., serves as the radiating element. The slot does not need to run perfectly parallel to the flow of the electromagnetic waves traveling through the hollow tube.

[0003] Because a single slot has low directivity, hollow tube antennas usually have multiple slots arranged in an antenna array. The simplest way to construct a hollow tube antenna array is to arrange the slots along the long sides of the rectangular cross section of the hollow tube, spaced half a wavelength apart, in a zigzag pattern relative to the center of the hollow tube. The zigzag pattern causes all slots to radiate with the same phase.

[0004] To serially produce such hollow tube antenna arrays in a cost-effective manner, two metal sections can be fabricated and then joined together. The hollow tube passage can then be oriented vertically, leaving the narrow side open for radiation. The joining of both sections is parallel to the narrow side of the hollow tube, so that the flow through the hollow tube is not interrupted. The metal sections do not even have galvanic contact, which means that the waveguiding performance of the hollow tube is not significantly affected.

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

[0006] [Patent Document 1] US Patent Application Publication No. 2020 / 203841 Summary of the Invention

[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 features of the independent claims.

[0008] Preferred embodiments are the subject of the respective dependent claims.

[0009] Thus, in a first aspect, the present invention relates to a radiating element for a waveguide antenna, the radiating element comprising a first hollow tube section capable of coupling 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, the first to third axes being pairwise orthogonal to each other, the radiating element further comprising a second hollow tube section having a second rectangular cross section, the short side of the second rectangular cross section extending parallel to the third axis, the long side of the second rectangular cross section extending parallel to the first axis, and the second hollow tube section extending along the second axis. A first dimension of the short side of the second rectangular cross section is smaller in a first region of the second hollow tube section than a second dimension of the short side of the second rectangular cross section 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 of the second hollow tube section and can be emitted through an open end of the second region of the second hollow tube section.

[0010] In a second aspect, the present invention relates to a waveguide antenna having a number of radiating elements according to the first aspect and a power splitting device configured to feed electromagnetic waves into the first hollow tube section 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, comprising: a first hollow tube section capable of coupling electromagnetic waves, the first hollow tube section having a first rectangular cross section, the short side of which extends parallel to a first axis, the long side of which extends 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; and a second hollow tube section having a second rectangular cross section, the short side of which extends parallel to the third axis, and the long side of which extends parallel to the first axis, and the second hollow tube section extending along the second axis. A first dimension of a shorter side of the second rectangular cross section in the first region of the second hollow tubular section is smaller than a second dimension of a shorter side of the second rectangular cross section in the second region of the second hollow tubular section. Electromagnetic waves can be fed from the first hollow tubular section to the second hollow tubular section through a slot in the first region of the second hollow tubular section and can be emitted through an open end of the second region of the second hollow tubular section. [Effects of the Invention]

[0012] The present invention provides independent radiating elements that can be fed by a power splitter device and then emit electromagnetic radiation.

[0013] The radiating element includes a first hollow tube section that serves to feed electromagnetic radiation into the second hollow tube section, the feeding being performed laterally into a slot in a first region of the second hollow tube section, i.e., perpendicular to the radiation opening formed by the opening of the second hollow tube section, thereby enabling a compact construction of the waveguide antenna, since multiple radiating elements can be arranged adjacent to each other with small spacing.

[0014] The compact configuration of the radiating element and the different short side dimensions of the first and second regions result in impedance transformation in the vertical dimension, allowing for a wide range of impedance matching from the vertical power divider to the radiating element.

[0015] The first and second dimensions of the shorter side of the second rectangular cross section are then subject to parameters that can be appropriately selected for impedance matching in the frequency range of the applied electromagnetic radiation, and the dimensions of the longer side of the second rectangular cross section and the dimension of the extension of the second hollow tube section along the second axis are subject to further parameters.

[0016] Dimensions here are understood to be the respective lengths.

[0017] In another embodiment of the radiating element, the second hollow tubular section has a third region between the first region of the second hollow tubular section and the second region of the second hollow tubular section, and the dimension of the short 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 by an angle, being 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 tubular section are planar. The second hollow tubular section can 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 tubular section is offset along a third axis with respect to the center of the second hollow tubular section, the dimension of this offset being in accordance with yet another parameter for impedance matching.

[0020] In another embodiment of the radiating element, the dimension of the longer 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 the wavelength of the electromagnetic wave for a given field of application of the radiating element.

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

[0022] In another embodiment of a method for manufacturing a radiating element for a waveguide antenna, the second hollow tube section has a third region between the first region of the second hollow tube section and the second region of the second hollow tube section, and 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.

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

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

[0025] The drawings show: [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 diagram showing a radiating element according to an embodiment of the present invention from diagonally above. [Figure 3]FIG. 3 is another schematic view showing the radiating element shown in FIG. 2 from obliquely above. [Figure 4] FIG. 4 is a schematic diagram showing the radiating element shown in FIGS. 2 and 3 from obliquely below. [Figure 5] FIG. 5 is a schematic cross-sectional view showing the radiating element shown in FIGS. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a radiating element according to another embodiment of the present invention. [Figure 7] FIG. 7 is a schematic exploded view showing a radiating element according to another embodiment of the present invention. [Figure 8] FIG. 8 is a flowchart of a method for fabricating a radiating element for a waveguide antenna according to an embodiment of the present invention.

[0026] In the various figures, identical elements or functionally identical elements and devices are designated by the same reference numerals. The numbering of the method steps is for general purposes and generally does not imply a particular temporal order. In particular, several method steps may be performed simultaneously. DETAILED DESCRIPTION OF THE INVENTION

[0027] 1 shows a schematic cross-sectional view of a waveguide antenna 10 having a power splitter 8 and four radiating elements 1a-1d. The power splitter 8 includes an input 81 to which an electromagnetic signal is supplied. The output of the electromagnetic signal is split by the power splitter 8, and the four radiating elements 1a-1d are each supplied with the electromagnetic signal. The amplitude and phase relationship of each of the radiating elements 1a-1d can be adjusted by the structure and dimensions of the power splitter 8.

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

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

[0030] The radiating element 1 includes a first hollow tubular section 2 into which electromagnetic waves can be coupled. The first hollow tubular section is configured as a rectangular parallelepiped, i.e., has a constant first rectangular cross section, the short sides of which extend parallel to a first axis X and the long sides of which extend parallel to a second axis Z. The first hollow tubular section extends along a third axis Y. The first to third axes X, Y, Z are pairwise orthogonal to each other.

[0031] The radiating element 1 further includes a second hollow tubular section 3,4, which has a second rectangular cross section. A shorter side of the second rectangular cross section is parallel to a third axis Y. A longer side of the second rectangular cross section is parallel to the first axis X. The second hollow tubular section 3,4 extends along a second axis Z. The second rectangular cross section varies along the extension of the second hollow tubular section 3,4 along the second axis Z. In the first section 3, the shorter side of the second rectangular cross section has a constant first dimension (width) that is smaller than a constant second dimension of the shorter side of the second rectangular cross section in the second section 4 of the second hollow tubular section 3,4.

[0032] The second hollow tubular section 3, 4 has a flat side surface, ie the second hollow tubular section 3, 4 is configured in an L-shape.

[0033] The first region 3 of the second hollow tube section 3,4 has a slot corresponding to the first rectangular cross section extending along the second axis Z. Electromagnetic waves can be fed from the first hollow tube section 2 to the second hollow tube section 3,4 via the slot in the first region 3 of the second hollow tube section 3,4. Electromagnetic radiation is then emitted via the open end of the second region 4 of the second hollow tube section 3,4.

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

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

[0036] 5 shows a schematic cross-sectional view of the radiating element 1 shown in FIGS. 2 to 4. The second hollow tubular section 3,4 has a first dimension W1 in the first region 3 of the second hollow tubular section 3,4 and a second dimension W2 in the second region 4 of the second hollow tubular section 3,4, relative to the shorter side of the second cross-section. The projection angle α of the second region 4 of the second hollow tubular section 3,4 is 90 degrees. Furthermore, the second region 4 of the second hollow tubular section 3,4 has a length L1 along the second axis Z.

[0037] 6 shows a schematic diagram of a radiating element 1', in which the angle α is greater than 90 degrees, i.e., the second hollow tubular section 3,4,7 has a third region 7 between the first region 3 of the second hollow tubular section 3,4,7 and the second region 4 of the second hollow tubular section 3,4,7, and the dimension of the short 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, overall, there are six parameters W1, W2, L1, La, Inp, α, which can be selected for impedance matching in the applied frequency range of electromagnetic radiation.

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

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

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

[0042] FIG. 7 shows a schematic exploded view of the radiating element 1″. The housing of the radiating element 1′ comprises a first part 6 and a second part 7 which are centrally coupled parallel to each other about a first axis X and about a third axis Y. This coupling may be achieved without a galvanic connection.

[0043] FIG. 8 shows a flow chart of a method for manufacturing radiating elements for a waveguide antenna, in particular the radiating elements 1a-1d;1;1';1" described above.

[0044] In method step S1, a first hollow tube section 2 into which electromagnetic waves can be coupled is constructed, the first hollow tube section 2 having a first rectangular cross section, the short sides of the first rectangular cross section extending parallel to a first axis X, the long sides of the first rectangular cross section extending parallel to a second axis Z, the first hollow tube section extending along a third axis Y, the first to third axes X, Y, Z being perpendicular to each other in pairs.

[0045] In step S2, a second hollow tube section 3,4,7 is constructed, the second hollow tube section 3,4,7 having a second rectangular cross section, the shorter side of the second rectangular cross section extending parallel to the third axis Y, the longer side of the second rectangular cross section extending parallel to the first axis X, and the second hollow tube section 3,4,7 extending along the second axis Z. A first dimension W1 of the shorter side of the second rectangular cross section in the first region 3 of the second hollow tube section 3,4,7 is smaller than a second dimension W2 of the shorter side of the second rectangular cross section in the second region 4 of the second hollow tube section 3,4,7. Electromagnetic waves can be fed from the first hollow tube section 2 to the second hollow tube section 3,4,7 through a slot in the first region 3 of the second hollow tube section 3,4,7 and can be emitted through the open end of the second region 4 of the second hollow tube section 3,4,7.

[0046] The second hollow tube section 3,4,7 may have a third region 7 between the first region 3 of the second hollow tube section 3,4,7 and the second region 4 of the second hollow tube section 3,4,7, 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.

Claims

1. In the radiating elements (1a-1d; 1; 1'; 1") for a waveguide antenna (10), a first hollow tubular section (2) into which electromagnetic waves can be coupled, the first hollow tubular section (2) having a first rectangular cross section, the short sides of the first rectangular cross section extending parallel to a first axis (X) and the long sides of the first rectangular cross section extending parallel to a second axis (Z), the first hollow tubular section (2) extending along a third axis (Y), the first to third axes (X, Y, Z) being pairwise orthogonal to each other; a second hollow tubular section (3, 4) having a second rectangular cross section, the short sides of which extend parallel to the third axis (Y) and the long sides of which extend parallel to the first axis (X), the second hollow tubular section (3, 4) extending along the second axis (Z); a first dimension (W1) of the short side of the second rectangular cross section in the first region (3) of the second hollow tubular section (3, 4) is smaller than a second dimension (W2) of the short side of the second rectangular cross section in the second region (4) of the second hollow tubular section (3, 4); A radiating element, wherein electromagnetic waves can be fed from the first hollow tubular section (2) to the second hollow tubular section (3, 4) through a slot in the first region (3) of the second hollow tubular section (3, 4) and can be emitted through the open end of the second region (4) of the second hollow tubular section (3, 4).

2. 2. The radiating element (1a-1d; 1; 1'; 1") according to claim 1, wherein the second hollow tubular section (3, 4) has a third region (7) between the first region (4) of the second hollow tubular section (3, 4) and the second region (3) of the second hollow tubular section (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. Radiating element (1a-1d; 1; 1'; 1'') according to claim 1 or 2, wherein three sides of said second hollow tubular section (3, 4) are planar.

4. A radiating element (1a-1d; 1; 1'; 1") according to any one of claims 1 to 3, wherein the slots in the first region (3) of the second hollow tubular section (3, 4) are offset along the third axis (X) with respect to the center of the second hollow tubular section (3, 4).

5. A radiating element (1a-1d; 1; 1'; 1") according to any one of claims 1 to 4, 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. A radiating element (1a-1d; 1; 1'; 1") according to any one of claims 1 to 5, wherein the extension (L1) of the second region (4) of the second hollow tube section (3, 4) along the second axis (Z) is less than or equal to a quarter of the wavelength of an electromagnetic wave.

7. In the waveguide antenna (10) (1a-1d; 1; 1'; 1"), a number of radiating elements (1a-1d; 1; 1'; 1") according to any one of claims 1 to 6, a power dividing device configured to feed electromagnetic waves into the first hollow tube section (2) of each of the radiating elements (1a-1d; 1; 1'; 1"); A waveguide antenna having

8. A method for manufacturing a radiating element (1a-1d; 1; 1'; 1") for a waveguide antenna (10), comprising the steps of: A first hollow tubular section (2) capable of coupling electromagnetic waves is configured, the first hollow tubular section (2) having a first rectangular cross section, a short side of the first rectangular cross section extending parallel to a first axis (X), a long side of the first rectangular cross section extending parallel to a second axis (Z), the first hollow tubular section (2) extending along a third axis (Y), the first to third axes (X, Y, Z) being paired and orthogonal to each other; a second hollow tubular section (3, 4) is constructed, said second hollow tubular section (3, 4) having a second rectangular cross section, the short sides of said second rectangular cross section extending parallel to said third axis (Y) and the long sides of said second rectangular cross section extending parallel to said first axis (X), said second hollow tubular section (3, 4) extending along said second axis (Z); and a first dimension (W1) of the short side of the second rectangular cross section in the first region (3) of the second hollow tubular section (3, 4) is smaller than a second dimension (W2) of the short side of the second rectangular cross section in the second region (4) of the second hollow tubular section (3, 4); Electromagnetic waves can be fed from the first hollow tubular section (2) to the second hollow tubular section (3, 4) through a slot in the first region (3) of the second hollow tubular section (3, 4) and can be emitted through the open end of the second region (4) of the second hollow tubular section (3, 4). method.

9. 9. The method according to claim 8, wherein the second hollow tubular section (3, 4) has a third region (7) between the first region (4) of the second hollow tubular section (3, 4) and the second region (3) of the second hollow tubular section (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).

10. 10. The method according to claim 8 or 9, wherein three sides of the second hollow tube section (3, 4) are planar.

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