Abstract
A multi-layer waveguide including at least three physical layers assembled into a multi-layer waveguide. The layers are a top layer, one or more intermediate layer, and a bottom layer. The multi-layer waveguide further includes a waveguide channel being an elongated aperture in at least one intermediate layer. At least one layer has a metasurface on a first surface facing a first adjoining layer, wherein the metasurface surrounds the elongated aperture and comprise thick and thin sections.
Claims
1. A multi-layer waveguide comprising at least three physical layers assembled into a multi-layer waveguide, wherein the layers are a top layer, one or more intermediate layer, and a bottom layer, the multi-layer waveguide comprises a waveguide channel being an elongated aperture in at least one intermediate layer, wherein at least one layer has a metasurface on a first surface facing a first adjoining layer, wherein the metasurface surrounds the elongated aperture and comprise thick and thin sections.
2. The multi-layer waveguide according to claim 1, wherein the first surface has a flat portion surrounding the metasurface, and wherein the thick sections have a thickness corresponding to the layer thickness at the flat portion and the thin sections have a thickness that is less than the thickness at the flat portion.
3. The multi-layer waveguide according to claim 1, wherein a second surface of the layer facing a second adjoining layer is a flat surface except for the elongated aperture.
4. The multi-layer waveguide according to claim 1, wherein the layers are stacked separate layers without elements extending between the layers.
5. The multi-layer waveguide according to claim 1, wherein each thick section has any one of a circular, elliptical, triangular, square, pentagonal, rectangular, rectangular, square, hexagonal, or rectangular shape.
6. The multi-layer waveguide according to claim 1, wherein the thick sections are arranged in rows parallel to the elongated aperture.
7. The multi-layer waveguide according to claim 1, wherein the thick sections are arranged at irregular distances from the elongated aperture.
8. The multi-layer waveguide according to claim 1, wherein the metasurface surrounds the elongated aperture.
9. The multi-layer waveguide according to claim 1, wherein the multi-layer waveguide comprise a first, second, and third intermediate layers each comprises an elongated aperture, and wherein the second intermediate layer further comprises a central member arranged within the elongated aperture.
10. The multi-layer waveguide according to claim 1, wherein the multi-layer waveguide comprises a first, second, and third intermediate layers wherein the second intermediate layer is a non-textured layer for integrated electronic chipsets.
11. The multi-layer waveguide according to claim 1, wherein the difference in thickness between the thick sections and the thin sections of the metasurface is less than the wavelength divided by 20.
12. The multi-layer waveguide according to claim 1, wherein the difference in thickness between the thick sections and the thin sections of the metasurface is less than the wavelength divided by 25.
13. The multi-layer waveguide according to claim 1, wherein any one of the top and bottom layer comprise a metasurface.
14. The multi-layer waveguide according to claim 1, wherein the multi-layer waveguide is implemented as a slotted waveguide antenna.
15. The multi-layer waveguide according to claim 1, wherein the top layer comprises antenna slots.
16. A method for producing a multi-layer waveguide according to claim 1.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0064] The invention is now described, by way of example, with reference to the accompanying drawings, in which:
[0065] FIG. 1 illustrates one embodiment of a multi-layer waveguide with layers comprising a metasurface, wherein the top layer is presented as an exploded view.
[0066] FIG. 2 illustrates one embodiment of an isometric cross-section of an intermediate layer.
[0067] FIG. 3 illustrates an exploded view of one embodiment of a multi-layer waveguide with layers comprising a metasurface.
[0068] FIG. 4 illustrates a cross-section of an embodiment as illustrated in FIG. 3.
[0069] FIG. 5 illustrates a cross-section of part of an intermediate layer where thin and thick sections of a metasurface is illustrated in detail.
[0070] FIG. 6 illustrates a cross-section showing one embodiment of metasurfaces in multiple layers wherein the metasurface is produced using chemical etching as the fabrication method.
[0071] FIG. 7 illustrates one embodiment showing a co-axial multi-layer waveguide with metasurfaces in multiple layers.
[0072] FIG. 8 illustrates a cross-section of one embodiment of a co-axial multi-layer waveguide with a flat layer between multiple layers with metasurfaces.
[0073] FIG. 9 illustrates a cross-section of one embodiment of a rectangular multi-layer waveguide with metasurfaces in a bottom layer.
[0074] FIG. 10 illustrates one embodiment wherein the metasurface section have a round shape.
[0075] FIG. 11 illustrates one embodiment wherein the thick and/or thin sections are unevenly arranged in the metasurface.
[0076] FIG. 12 illustrates one embodiment wherein multiple waveguides are arranged as slotted waveguide antennas in one unit.
[0077] FIG. 13 illustrates a bottom view of a top layer according to the embodiment as illustrated in FIG. 12.
[0078] FIG. 14 illustrates one embodiment of a multi-layer waveguide arranged as a slotted waveguide antenna.
[0079] FIG. 15 illustrates one embodiment of a multi-layer waveguide arranged as a slotted waveguide antenna, wherein corrugations to reduce unwanted signal propagations are arranged in the extension direction of the waveguide channel.
DESCRIPTION OF EMBODIMENTS
[0080] In the following, a detailed description of the different embodiments of the invention is disclosed under reference to the accompanying drawings. All examples herein should be seen as part of the general description and are therefore possible to combine in any way of general terms. Individual features of the various embodiments and aspects may be combined or exchanged unless such combination or exchange is clearly contradictory to the overall function of the multi-layer waveguide, arrangement, or production method thereof.
[0081] Briefly described the solution relates to a compact multi-layer waveguide without any requirement for electrical and galvanic contact between the layers. The multi-layer waveguide has metasurfaces in layers arranged as leak suppressing structure for reducing energy leakage between the layers of the waveguide. The metasurface comprise multiple thick and thin sections surrounding a waveguide channel.
[0082] FIG. 1 illustrates one embodiment of a multi-layer waveguide 1 with multiple layers 21, 2a, 2b, 2c, 22 of a multi-layer waveguide. The intermediate layers 2a, 2b, 2c, 2d, 2e each has an elongated aperture 7 that alone or together with elongated apertures of other layers creates a waveguide channel 77. The elongated aperture 7 is in some or all of the intermediate layers surrounded by a metasurface.
[0083] FIG. 2 illustrates a cross-section of part of an intermediate layer 2b. The layer comprises an elongated aperture 7 which off only part is visible in the illustration of FIG. 2. The elongated aperture 7 is surrounded by a metasurface 3 comprising thick 3a and thin 3b sections. The thick 3a and thin 3b sections together creates the metasurface, wherein the metasurface is leak suppressing in the way that it helps guide the wave and keep it within the waveguide channel 77 that the elongated aperture 7 is part of.
[0084] FIG. 2 further illustrates a flat portion 4 surrounding the metasurface 3. The flat portion 4, in one embodiment has the same thickness as the thick sections 3a. In the embodiment as illustrated in FIG. 2 the thick sections 3a are arranged in straight rows 6a, 6b, 6c. In one embodiment the number of straight rows 6a, 6b, 6c could be one, two, three or more at any or all sides of the elongated aperture 7.
[0085] FIG. 3 illustrates one embodiment of the multi-layer waveguide 1 wherein the layers are spaced apparat. This exploded view illustrates an important feature of the multi-layer waveguide 1 in that no galvanic, electric, or physical connection is required between the layers. I.e. a small gap can exist between the layers. This gap could for example be an uncontrolled air gap from production of the layers. The gap could also be on micron or even an atomic level. However, it shall be noted that the size of the gap as illustrated in FIG. 3 is only for illustration, the gap between the layers could typically be anywhere between 0 and 15 micrometers.
[0086] FIG. 4 illustrates a cross-section of one embodiment of a multi-layer waveguide 1 wherein the entry 30 and exit 31 openings are visible. Those openings 30, 31 are the openings wherein the wave enter and exits the waveguide channel 77. FIG. 4 further illustrates a first 5a and second 5b surface identified for one intermediate layer 2b. It shall be noted that each layer comprises a first 5a and second 5b surface. The entry 30 and exit 31 openings don’t have to be arranged in the bottom layer 22. In another embodiment the entry 30 and exit 31 openings are instead arranged in the top layer 21. In yet another embodiment the entry 30 and exit 31 openings are arranged in different layers, for example, the entry opening 30 could be arranged in the top layer 21 and the exit opening 31 in the bottom layer 22, or vice versa.
[0087] FIG. 5 illustrates parts of an intermediate layer 2a, 2b, ..., 2n or part of a top 21 or bottom 22 layer with a metasurface 3. FIG. 5 illustrates differences in thickness between the thick 3a and thin 3b sections as well as the flat portion 4. The difference can for example be between 50-70%, 50-60%, 55-65%, or 60-70% of the total thickness of the layer, however the difference in thickness might vary also outside said range.
[0088] FIG. 6 illustrates one embodiment of the metasurfaces 3 wherein the metasurface 3 was produced by metal chemical etching creating a characteristic shape of the edges in the metasurface, the shape of the edges in the metasurface becomes rounded. It shall be noted that other production methods such as CNC, laser cutting etc. also are possible.
[0089] FIG. 7 illustrates a co-axial multi-layer waveguide 1 wherein the waveguide channel 77 comprises a central member 8 arranged within the elongated aperture 7 of one intermediate layer 2a, 2b, 2c, ..., 2n. The center member 8 is attached to the rest of the layer at one or more place connecting the central member to the layer and keeping it in place.
[0090] FIG. 8 illustrates one embodiment of a co-axial multi-layer waveguide 1 wherein the top 21 and bottom 22 layers have metasurfaces 3. It shall be noted that the top 21 and bottom 22 layers in some embodiments have metasurfaces 3 and in some they don’t. Further, in some embodiment, as illustrated in for example FIG. 8, one or more intermediate layer doesn’t have a metasurface 3.
[0091] FIG. 9 illustrates another embodiment of a multi-layer waveguide 1 wherein the top layer 21 don’t have any metasurface but the intermediate layers 2a, 2b, 2c and the bottom layer 22 have metasurfaces.
[0092] FIG. 10 illustrates one embodiment of an intermediate layer 2a, 2b, 2c, ..., 2n, wherein the thick sections 3a have a round shape. It shall be noted that the shape is not important to the functionality and the metasurface 3 may have thick sections 3a of many different shapes, both in the same and in different metasurfaces 3.
[0093] FIG. 11 illustrates another embodiment wherein the thick sections 3a of the metasurface 3 are randomly placed around the elongated aperture 7. FIG. 11 is a representation of how the thick sections 3a could be arranged but it shall be noted that describes herein is only different possible embodiments and other arrangements of the thick sections 3a is also possible within the scope of the claims. The small gap between the layers and the metasurface provide the electromagnetic bandgap (EBG) structure.
[0094] FIG. 12 illustrates an exploded isometric view of a multi-layer slotted waveguide antenna 40 as one implementation of waveguides 1 as described herein. The embodiment as illustrated in FIG. 12 shows a top layer 21, an intermediate layer 2a, and a bottom layer 22. The top layer 21 comprise antenna slots 41 and corrugations 42 arranged at one end of the waveguide 1. The intermediate layer 2a comprise elongated apertures 7 providing routing in each waveguide 1. The bottom 22 and the top layer 21 comprise meta surfaces 3 arranged to surround the elongated apertures 7 of the intermediate layer 2a.
[0095] The elongated apertures 7 as illustrated in FIG. 12 comprise support structures for enhancing the mechanical support of the layer. The support structures are arranged within the elongated apertures 7 providing an embodiment wherein multiple elongated apertures 7 are arranged instead of a single aperture extending the entire length. In one embodiment this is merely for structural support.
[0096] FIG. 13 illustrates a bottom view of the top layer 21 as illustrated in FIG. 12. As shown, the top layer 21 in one embodiment comprises meta surfaces 3 arranged to surround the elongated apertures 7 of the intermediate layer 2a. As understood, the embodiments as illustrated in FIGS. 12 and 13 are merely examples of how the solution as described herein could be implemented as a slotted waveguide antenna 40. FIGS. 12 and 13 further illustrates how the routing of the waveguide 1 may differ depending of the implementation. For example, the routing may in one embodiment be straight and in another comprise one or more turns.
[0097] FIG. 14 illustrate one embodiment of a multi-layer waveguide 1 implemented as a slotted waveguide antenna 40. FIG. 15 illustrate a slightly more complex multi-layer waveguide 1 implemented as a slotted waveguide antenna 40 wherein corrugations 42 are arranged to reduce ripple in the transmission pattern. The corrugations 42 reduce surface currents in the top layer and thus enhance the propagation pattern. As illustrated in FIG. 14 the corrugations 42 extend through the top 21 and intermediate layer 2a. In another embodiment wherein the multi-layer waveguide implemented as a slotted waveguide antenna 40 comprise additional intermediate layers 2b, 2c, ..., 2n, the corrugations 42 extends through the top layer 21 and the intermediate layers 2a, 2b, 2c, ..., 2n. In yet another embodiment the corrugations 42 extend through at least the top layer 21 and at least some of the intermediate layers 2a, 2b, 2c, ..., 2n.
