Radiating element, waveguide antenna, and method for manufacturing a radiating element
Patent Information
- Application Number
- EP2023833829
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-08
- Filing Date
- 2023-12-20
- Publication Date
- 2025-12-17
AI Technical Summary
Waveguide antennas with single slots have low directivity, requiring multiple slots in an array configuration, which complicates manufacturing and design, especially in achieving efficient electromagnetic wave emission with phase coherence.
A radiating element comprising a first waveguide section with a rectangular cross-section and a second waveguide section, where the electromagnetic wave is fed laterally into the second section via a slot, allowing for compact design and impedance matching through varying dimensions and angles, enabling efficient electromagnetic radiation emission.
The solution enables compact, efficient, and impedance-matched electromagnetic radiation emission, allowing multiple radiating elements to be arranged closely, improving the directivity and manufacturing efficiency of waveguide antennas.
Smart Images
Figure EP2023086915_15082024_PF_FP
Abstract
Description
[0001] Description
[0002] title
[0003] Radiating element. Waveguide antenna and method for manufacturing a radiating element
[0004] The present invention relates to a radiating element for a waveguide antenna, a waveguide antenna and a method for producing a radiating element.
[0005] State of the art
[0006] In a waveguide, electromagnetic energy is transported within a metallic cavity. The waveguide can be part of a waveguide antenna. In the simplest case, a slot is formed in the waveguide, forming an interface between the inner region of the waveguide and free space, i.e., serving as a radiating element. This slot does not have to run completely parallel to the currents of the electromagnetic wave traveling through the waveguide.
[0007] Since a single slot has only a low directivity, waveguide antennas typically comprise multiple slots forming an antenna array. The simplest way to create a waveguide antenna array is to place the slots along the long side of a rectangular cross-section of the waveguide, maintaining a spacing of half a wavelength, creating a zigzag pattern relative to the center of the waveguide. This zigzag pattern ensures that all slots radiate with the same phase.
[0008] In the series production of such waveguide antenna arrays using cost-effective processes, two metal parts can be manufactured and then joined together. The waveguide channels can be arranged vertically, leaving the narrow side free for radiation. The two parts are connected parallel to the narrow side of the waveguide, thus ensuring that the currents flowing through the waveguide are not disturbed. The two metal parts do not even need to be in galvanic contact, so the guiding performance of the waveguide is hardly affected. To achieve the required distance between the radiating elements, US 2020 / 203841 A1 proposes a center-fed open waveguide antenna array, with the feeding waveguide connected to elements formed by two openings.
[0009] Disclosure of the invention
[0010] The invention provides a radiating element for a waveguide antenna, a waveguide antenna and a method for producing a radiating element for a waveguide antenna having the features of the independent patent claims.
[0011] Preferred embodiments are the subject of the respective subclaims.
[0012] According to a first aspect, the invention accordingly relates to a radiating element for a waveguide antenna. The radiating element comprises a first waveguide section into which an electromagnetic wave can be coupled, wherein the first waveguide section has a first rectangular cross-section, wherein a narrow side of the first rectangular cross-section runs parallel to a first axis, wherein a wide side of the first rectangular cross-section runs parallel to a second axis, wherein the first waveguide section extends along a third axis, and wherein the first to third axes are orthogonal to one another in pairs.The radiating element further comprises a second waveguide section, wherein the second waveguide section has a second rectangular cross-section, wherein a narrow side of the second rectangular cross-section runs parallel to the third axis, wherein a wide side of the second rectangular cross-section runs parallel to the first axis, and wherein the second waveguide section extends along the second axis. A first dimension of the narrow side of the second rectangular cross-section is smaller in a first region of the second waveguide section than a second dimension of the narrow side of the second rectangular cross-section in a second region of the second waveguide section.The electromagnetic wave can be fed from the first waveguide section into the second waveguide section via a slot in the first region of the second waveguide section and emitted via an open end of the second region of the second waveguide section. According to a second aspect, the invention relates to a waveguide antenna having a plurality of radiating elements according to the first aspect and a power splitting device configured to feed an electromagnetic wave into the respective first waveguide sections of the radiating elements.
[0013] According to a third aspect, the invention relates to a method for producing a radiating element for a waveguide antenna. A first waveguide section is formed into which an electromagnetic wave can be coupled, wherein the first waveguide section has a first rectangular cross-section, wherein a narrow side of the first rectangular cross-section runs parallel to a first axis, wherein a wide side of the first rectangular cross-section runs parallel to a second axis, wherein the first waveguide section extends along a third axis, and wherein the first to third axes are orthogonal to one another in pairs.A second waveguide section is formed, the second waveguide section having a second rectangular cross-section, a narrow side of the second rectangular cross-section running parallel to the third axis, a wide side of the second rectangular cross-section running parallel to the first axis, and the second waveguide section extending along the second axis. A first dimension of the narrow side of the second rectangular cross-section in a first region of the second waveguide section is smaller than a second dimension of the narrow side of the second rectangular cross-section in a second region of the second waveguide section.The electromagnetic wave can be fed from the first waveguide section into the second waveguide section via a slot in the first region of the second waveguide section and emitted via an open end of the second region of the second waveguide section.
[0014] Advantages of the invention
[0015] The invention provides independent radiating elements which can be fed by a power splitting device and then emit electromagnetic radiation.
[0016] The emitting element comprises a first waveguide section, which serves to feed the electromagnetic radiation into a second waveguide section. The feed is made laterally into the slot in the first region of the second waveguide section, i.e., perpendicular to the emitting aperture formed by the opening of the second waveguide section. This enables a compact design of the waveguide antenna, since several emitting elements can be arranged adjacent to one another at a short distance.
[0017] The radiating element is of compact construction and enables a wide impedance matching from a vertical power dividing device to the radiating element by means of an impedance transformation in the vertical dimension by means of the different dimensions of the narrow side with respect to the first region and the second region.
[0018] The first dimension and the second dimension of the narrow side of the second rectangular cross-section correspond to parameters that can be selected to suit the impedance matching in the frequency range of the electromagnetic radiation used. The dimension of the wide side of the second rectangular cross-section and the dimension of the extension of the second waveguide section along the second axis correspond to further parameters.
[0019] Dimensions here refer to the respective lengths.
[0020] According to a further embodiment of the radiating element, the second waveguide section has a third region between the first region of the second waveguide section and the second region of the second waveguide section, wherein a dimension of the narrow side of the second rectangular cross-section in the third region increases linearly from the first dimension to the second dimension. The linear increase, which can be expressed as an angle, represents a further parameter that can be used for impedance matching.
[0021] According to a further embodiment of the radiating element, three side surfaces of the second waveguide section are planar. The second waveguide section can, for example, be L-shaped.
[0022] According to a further embodiment of the radiating element, the slot in the first region of the second waveguide section is offset along the third axis relative to a center of the second waveguide section. The dimension of the offset corresponds to a further parameter for impedance matching.
[0023] According to a further embodiment of the radiating element, a dimension of the wide side of the second rectangular cross-section is greater than or equal to half a wavelength of the electromagnetic wave and less than or equal to three-quarters of a wavelength of the electromagnetic wave, for a given application range of the radiating element.
[0024] According to a further embodiment of the radiating element, an extension of the second region of the second waveguide section along the second axis is less than or equal to a quarter wavelength of the electromagnetic wave.
[0025] According to a further embodiment of the method for producing the radiating element for a waveguide antenna, the second waveguide section has a third region between the first region of the second waveguide section and the second region of the second waveguide section, wherein a dimension of the narrow side of the second rectangular cross-section in the third region increases linearly from the first dimension to the second dimension.
[0026] According to a further embodiment of the method for producing the radiating element for a waveguide antenna, three side surfaces of the second waveguide section are planar.
[0027] Further advantages, features and details of the invention will become apparent from the following description, in which various embodiments are described in detail with reference to the drawing.
[0028] Short description of the drawings
[0029] They show:
[0030] Figure 1 shows a schematic cross-sectional view of a waveguide antenna with radiating elements according to an embodiment of the invention; Figure 2 shows a schematic oblique top view of a radiating element according to an embodiment of the invention;
[0031] Figure 3 is a further schematic view obliquely from above of the radiating element shown in Figure 2;
[0032] Figure 4 is a schematic oblique view from below of the radiating element shown in Figures 2 and 3;
[0033] Figure 5 is a schematic cross-sectional view of the radiating element shown in Figures 2 to 4;
[0034] Figure 6 is a schematic cross-sectional view of a radiating element according to a further embodiment of the invention;
[0035] Figure 7 is a schematic exploded view of a radiating element according to a further embodiment of the invention; and
[0036] Figure 8 is a flowchart of a method for manufacturing a radiating element for a waveguide antenna according to an embodiment of the invention.
[0037] In all figures, identical or functionally equivalent elements and devices are provided with the same reference numerals. The numbering of process steps serves the purpose of clarity and is generally not intended to imply a specific chronological order. In particular, several process steps can be performed simultaneously.
[0038] Description of the embodiments
[0039] Figure 1 shows a schematic cross-sectional view of a waveguide antenna 10 with a power splitter 8 and four radiating elements 1a-1d. The power splitter 8 includes an input 81 fed with an electromagnetic signal. The power of the electromagnetic signal is divided by the power splitter 8, and the four radiating elements 1a-1d are fed with respective electromagnetic signals. The amplitudes and phase relationships for the individual radiating elements 1a-1d can be adjusted by the design and dimensions of the power splitter 8.
[0040] The invention is not limited to a specific number of radiating elements la- Id.
[0041] Figure 2 shows a schematic view of a radiating element 1 obliquely from above, illustrating the waveguides. Figure 3 shows another schematic view of the radiating element 1 shown in Figure 2, illustrating the housing. Figure 4 shows a schematic view obliquely from below of the radiating element 1 shown in Figures 2 and 3, again illustrating the waveguides.
[0042] The emitting element 1 comprises a first waveguide section 2, into which an electromagnetic wave can be coupled. The first waveguide section is cuboid-shaped and thus has a constant first rectangular cross-section, with a narrow side of the first rectangular cross-section running parallel to a first axis X, and a wide side of the first rectangular cross-section running parallel to a second axis Z. The first waveguide section extends along a third axis Y. The first to third axes X, Y, Z are orthogonal to each other in pairs.
[0043] The radiating element 1 further comprises a second waveguide section 3, 4, wherein the second waveguide section 3, 4 has a second rectangular cross-section. A narrow side of the second rectangular cross-section is parallel to the third axis Y. A wide side of the second rectangular cross-section is parallel to the first axis X. The second waveguide section 3, 4 extends along the second axis Z. The second rectangular cross-section varies along the extension of the second waveguide section 3, 4 along the second axis Z. In a first region 3, the narrow side of the second rectangular cross-section has a constant first dimension (width), which is smaller than a constant second dimension of the narrow side of the second rectangular cross-section in a second region 4 of the second waveguide section 3, 4. Three side surfaces of the second waveguide section 3, 4 are planar, i.e.the second waveguide section 3, 4 is L-shaped.
[0044] The first region 3 of the second waveguide section 3, 4 has a slot extending along the second axis Z and corresponding to the first rectangular cross-section. The electromagnetic wave can be fed from the first waveguide section 2 via the slot into the first region 3 of the second waveguide section 3, 4. The electromagnetic radiation is then emitted via an open end of the second region 4 of the second waveguide section 3, 4.
[0045] The slot in the first region 3 of the second waveguide section 3, 4 is offset along the third axis X with respect to a center of the second waveguide section 3, 4. The slot is arranged at a distance Inp from one side of the first region 3 of the second waveguide section 3, 4.
[0046] The wide side of the second rectangular cross-section of the second waveguide section 3, 4 has a length La.
[0047] Figure 5 shows a schematic cross-sectional view of the radiating element 1 shown in Figures 2 to 4. The second waveguide section 3, 4 has, with respect to the narrow side of the second cross section, a first dimension W1 in the first region 3 of the second waveguide section 3, 4, and has a second dimension W2 in the second region 4 of the second waveguide section 3, 4. An angle α of a projecting part of the second region 4 of the second waveguide section 3, 4 is 90 degrees. The second region 4 of the second waveguide section 3, 4 further has a length LI along the second axis Z.
[0048] Figure 6 shows a schematic view of a radiating element 1', wherein the angle α is greater than 90 degrees. The second waveguide section 3, 4, 7 thus has a third region 7 between the first region 3 of the second waveguide section 3, 4, 7 and the second region 4 of the second waveguide section 3, 4, 7, wherein a dimension of the narrow side of the second rectangular cross-section in the third region increases linearly from the first dimension W 1 to the second dimension W 2. In total, there are thus six parameters W 1, W 2, L 1, L a, L np, α, which can be selected for impedance matching in the used frequency range of the electromagnetic radiation.
[0049] The dimension La of the wide side of the second rectangular cross-section is greater than or equal to half a wavelength Xo of the electromagnetic wave and less than or equal to three-quarters of a wavelength Xo of the electromagnetic wave:
[0050] Xo / 2 < La < 3Xo / 4.
[0051] The extension LI of the second region 4 of the second waveguide section along the second axis Z is less than or equal to a quarter wavelength Xo of the electromagnetic wave:
[0052] LI < X0 / 4.
[0053] Furthermore, the angle a is greater than or equal to 90 degrees.
[0054] Figure 7 shows a schematic exploded view of a radiating element 1'. The housing of the radiating element 1' comprises a first part 6 and a second part 7, which are connected to each other centrally parallel to the first axis X and the third axis Y. The connection may not be galvanically formed.
[0055] Figure 8 shows a flow diagram of a method for producing a radiating element for a waveguide antenna, in particular one of the radiating elements 1a-1d; 1; 1'; 1" described above.
[0056] In a first method step S1, a first waveguide section 2 is formed into which an electromagnetic wave can be coupled, wherein the first waveguide section 2 has a first rectangular cross-section, wherein a narrow side of the first rectangular cross-section runs parallel to a first axis X, wherein a wide side of the first rectangular cross-section runs parallel to a second axis Z, wherein the first waveguide section extends along a third axis Y, and wherein the first to third axes X, Y, Z are orthogonal to one another in pairs.In a step S2, a second waveguide section 3, 4, 7 is formed, wherein the second waveguide section 3, 4, 7 has a second rectangular cross-section, wherein a narrow side of the second rectangular cross-section runs parallel to the third axis Y, wherein a wide side of the second rectangular cross-section runs parallel to the first axis X, and wherein the second waveguide section 3, 4, 7 extends along the second axis Z. A first dimension W1 of the narrow side of the second rectangular cross-section in a first region 3 of the second waveguide section 3, 4, 7 is smaller than a second dimension W2 of the narrow side of the second rectangular cross-section in a second region 4 of the second waveguide section 3, 4, 7.The electromagnetic wave can be fed from the first waveguide section 2 into the second waveguide section 3, 4, 7 via a slot in the first region 3 of the second waveguide section 3, 4, 7 and emitted via an open end of the second region 4 of the second waveguide section 3, 4, 7.
[0057] The second waveguide section 3, 4, 7 may have a third region 7 between the first region 3 of the second waveguide section 3, 4, 7 and the second region 4 of the second waveguide section, wherein a dimension of the narrow side of the second rectangular cross-section in the third region 7 increases linearly from the first dimension W 1 to the second dimension W 2.
Claims
Claims 1. Radiating element (1a-1d; 1; 1'; 1”) for a waveguide antenna (10), comprising: a first waveguide section (2) into which an electromagnetic wave can be coupled, wherein the first waveguide section (2) has a first rectangular cross-section, wherein a narrow side of the first rectangular cross-section runs parallel to a first axis (X), wherein a wide side of the first rectangular cross-section runs parallel to a second axis (Z), wherein the first waveguide section (2) extends along a third axis (Y), and wherein the first to third axes (X, Y, Z) are orthogonal to one another in pairs;and a second waveguide section (3, 4), wherein the second waveguide section (3, 4) has a second rectangular cross-section, wherein a narrow side of the second rectangular cross-section runs parallel to the third axis (Y), wherein a wide side of the second rectangular cross-section runs parallel to the first axis (X), and wherein the second waveguide section (3, 4) extends along the second axis (Z); wherein a first dimension (W1) of the narrow side of the second rectangular cross-section in a first region (3) of the second waveguide section (3, 4) is smaller than a second dimension (W2) of the narrow side of the second rectangular cross-section in a second region (4) of the second waveguide section (3, 4);and wherein the electromagnetic wave can be fed from the first waveguide section (2) into the second waveguide section (3, 4) via a slot in the first region (3) of the second waveguide section (3, 4) and can be emitted via an open end of the second region (4) of the second waveguide section (3, 4); 2. Radiating element (la- Id; 1; 1'; 1”) according to claim 1, wherein the second Waveguide section (3, 4) has a third region (7) between the first region (4) of the second waveguide section (3, 4) and the second region (3) of the second waveguide section (3, 4), wherein a dimension of the narrow side of the second rectangular cross-section in the third region (7) increases linearly from the first dimension (Wl) to the second dimension (W2).
3. Radiating element (1a-1d; 1; 1'; 1”) according to claim 1 or 2, wherein three side surfaces of the second waveguide section (3, 4) are planar.
4. Radiating element (1a-1d; 1; 1'; 1”) according to one of the preceding claims, wherein the slot in the first region (3) of the second waveguide section (3, 4) is offset along the third axis (X) with respect to a center of the second waveguide section (3, 4).
5. Radiating element (la-ld; 1; 1'; 1”) according to one of the preceding claims, wherein a dimension (La) of the wide side of the second rectangular cross-section is greater than or equal to half a wavelength of the electromagnetic wave and less than or equal to three-quarters of a wavelength of the electromagnetic wave.
6. Radiating element (1a-1d; 1; 1'; 1”) according to one of the preceding claims, wherein an extension (LI) of the second region (4) of the second waveguide section (3, 4) along the second axis (Z) is less than or equal to a quarter wavelength of the electromagnetic wave.
7. Waveguide antenna (10) (la-ld; 1; 1'; 1") with: a plurality of radiating elements (la-ld; 1; 1'; 1") according to one of the preceding claims; and a power splitting device which is designed to feed an electromagnetic wave into the respective first waveguide sections (2) of the radiating elements (la-ld; 1; 1'; 1").
8. A method for producing a radiating element (la-ld; 1; 1'; 1”) for a waveguide antenna (10), comprising the steps: Forming a first waveguide section (2) into which an electromagnetic wave can be coupled, wherein the first waveguide section (2) has a first rectangular cross-section, wherein a narrow side of the first rectangular cross-section runs parallel to a first axis (X), wherein a wide side of the first rectangular cross-section runs parallel to a second axis (Z), wherein the first waveguide section (2) extends along a third axis (Y), and wherein the first to third axes (X, Y, Z) are orthogonal to one another in pairs; and Forming a second waveguide section (3, 4), wherein the second waveguide section (3, 4) has a second rectangular cross-section, wherein a narrow side of the second rectangular cross-section runs parallel to the third axis (Y), wherein a wide side of the second rectangular cross-section runs parallel to the first axis (X), and wherein the second waveguide section (3, 4) extends along the second axis (Z); wherein a first dimension (W1) of the narrow side of the second rectangular cross-section in a first region (3) of the second waveguide section (3, 4) is smaller than a second dimension (W2) of the narrow side of the second rectangular cross-section in a second region (4) of the second waveguide section (3, 4);and wherein the electromagnetic wave can be fed from the first waveguide section (2) into the second waveguide section (3, 4) via a slot in the first region (3) of the second waveguide section (3, 4) and can be emitted via an open end of the second region (4) of the second waveguide section (3, 4); 9. The method according to claim 8, wherein the second waveguide section (3, 4) has a third region (7) between the first region (4) of the second waveguide section (3, 4) and the second region (3) of the second waveguide section (3, 4), wherein a dimension of the narrow 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. The method according to claim 8 or 9, wherein three side surfaces of the second waveguide section (3, 4) are planar.