MULTI-LAYER FILTER, ARRANGEMENT, AND METHOD FOR PRODUCTION THEREOF

Abstract

A multi-layer signal filter includes at least three physical layers. Each layer has through going apertures arranged with an offset to apertures of at least one adjoining layer, each layer further has a filter channel opening for receiving signals to be filtered. The apertures are arranged along a perimeter outside the filter channel opening and the apertures are arranged with a central surface portion increasing the edge length of the aperture.

Claims

1. A multi-layer signal filter comprising at least three physical layers, wherein each layer has through going apertures arranged with an offset to apertures of at least one adjoining layer, each layer further has a filter channel opening for receiving signals to be filtered, wherein the apertures are arranged along a perimeter outside the filter channel opening, and wherein the apertures are arranged with a central surface portion increasing the edge length of the aperture.

2. The multi-layer signal filter according to claim 1, wherein the filter channel openings of all layers in the multi-layer signal filter has at least partly overlapping areas creating a filter channel through the multi-layer signal filter.

3. The multi-layer signal filter according to claim 1, wherein the apertures of two adjoining layers in the multi-layer signal filter offsets such that an open space of said apertures completely surrounds the filter channel of the two layers.

4. The multi-layer signal filter according to claim 1, wherein the apertures are arranged periodically along a perimeter outside the filter channel opening of each layer.

5. The multi-layer signal filter according to claim 1, wherein every second layer in the multi-layer signal filter has the same number and pattern of apertures.

6. The multi-layer signal filter according to claim 1, wherein the apertures at each layer are arranged in a pattern selected from any one of a circular, rectangular, square, and elliptical patterns along the perimeter outside the filter channel opening.

7. The multi-layer signal filter according to claim 6, wherein the offset between the apertures of two adjoining layers corresponds to moving the apertures along the perimeter of the pattern around its center with 360/(n*2) degrees, where n is the number of apertures in the layer.

8. The multi-layer signal filter according to claim 1, wherein the apertures of each layer are arranged at a center-to-center distance of any one of less than 75% of a wavelength, less than 50% of a wavelength, and 50% of a wavelength of the signal the multi-layer signal filter is designed for.

9. The multi-layer signal filter according to claim 1, wherein each aperture encompasses its central surface portion to at least 75% of the aperture edge length.

10. The multi-layer signal filter according to claim 1, wherein the offset between the apertures of two adjoining layers corresponds to the any one of the length, width, and diameter of the central surface portion.

11. The multi-layer signal filter according to claim 1, wherein the at least three layers comprise an entry layer, an intermediate layer, and an exit layer, wherein the entry layer has the same number and pattern of apertures as the exit layer.

12. The multi-layer signal filter according to claim 1, wherein each aperture of each layer has an overlapping portion of two apertures of an adjoining layer.

13. The multi-layer signal filter according to claim 1, wherein the distance between the layers of the multi-layer signal filter is between 0 and 50 microns.

14. The multi-layer signal filter according to claim 1, wherein the multi-layer signal filter is an air-filled waveguide filter.

15. A multi-layer signal filter array, comprising a plurality of multi-layer signal filters 1 arranged in a single unit, wherein the multi-layer signal filters are filters according to claim 1.

16. The multi-layer signal filter according to claim 2, wherein the apertures of two adjoining layers in the multi-layer signal filter offsets such that an open space of said apertures completely surrounds the filter channel of the two layers.

17. The multi-layer signal filter according to claim 2, wherein the apertures are arranged periodically along a perimeter outside the filter channel opening of each layer.

18. The multi-layer signal filter according to claim 3, wherein the apertures are arranged periodically along a perimeter outside the filter channel opening of each layer.

19. The multi-layer signal filter according to claim 2, wherein every second layer in the multi-layer signal filter has the same number and pattern of apertures.

20. The multi-layer signal filter according to claim 3, wherein every second layer in the multi-layer signal filter has the same number and pattern of apertures.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0070] The invention is now described, by way of example, with reference to the accompanying drawings, in which:

[0071] FIG. 1 illustrates layers for one embodiment of a multi-layer filter.

[0072] FIG. 2 illustrates another view of layers for one embodiment of a multi-layer filter.

[0073] FIG. 3 illustrates layers for another embodiment of a multi-layer filter.

[0074] FIG. 4 illustrates a cross-section view of an embodiment of a multi-layer filter wherein the filter channel is shown.

[0075] FIG. 5 illustrates an embodiment of a multi-layer filter array.

[0076] FIG. 6 illustrates one embodiment of a multi-layer filter array and an antenna array.

[0077] FIG. 7 illustrates one embodiment of an assembled multi-layer filter.

[0078] FIG. 8 illustrates a vertical cross-section of an assembled multi-layer filter.

[0079] FIG. 9 illustrate examples of aperture shapes for layers of a multi-layer filter.

[0080] FIG. 10 illustrates two layers for one embodiment of a multi-layer filter, wherein a transparent view shows the offset of apertures in the two layers.

DESCRIPTION OF EMBODIMENTS

[0081] 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 filter, arrangement, or production method thereof.

[0082] Briefly described the solution relates to a multi-layer filter without any requirement for electrical and galvanic contact between the layers. The multi-layer filter has a leak suppressing structure for reducing leakage between the layers of said filter. The leak suppressing structure comprise multiple apertures that are arranged along at least one perimeter outside the filter channel and the apertures are arranged with an offset between the layers creating an EBG-structure (electromagnetic band gap). The apertures further have an improved design to enable reduction of the size of the multi-layer filter.

[0083] FIG. 1 illustrates one embodiment of multiple layers 2a, 2b, 2c, 2d, 2e of a multi-layer filter. The layers 2a, 2b, 2c, 2d, 2e each has a filter channel opening 77 for a signal to be filtered. In the embodiment as illustrated in FIG. 1 each layer solely has one filter channel opening 77 and thus the multi-layer filter is a single multi-layer filter 1. However, in other embodiment multiple filter channel openings 77 might be arranged in a single layer, i.e. for use as a multi-layer filter array 10.

[0084] FIG. 1 further illustrates multiple apertures 3 arranged around a perimeter outside the filter channel opening 77. In the embodiment as illustrated in FIG. 1 the apertures 3 are arranged in a circle pattern. It is further shown one example of offsets between apertures 3 of different layers 2a, 2b, 2c, 2d, 2e and that the filter channel opening 77 of the different layers 2a, 2b, 2c, 2d, 2e have different sizes creating characteristics of the filter 1.

[0085] FIG. 2 illustrates the embodiment of FIG. 1 with the layers 2a, 2b, 2c, 2d, 2e separately illustrated. Multiple apertures 3 of each layer 2a, 2b, 2c, 2d, 2e are shown as well as central surface portions 5 for each aperture 3.

[0086] FIG. 3 illustrates another embodiment of a multi-layer filter 1 in a non-assembled state. The embodiment of FIG. 3 illustrates a filter with another number of layers 2a, 2b, 2c, . . . , 2n.

[0087] FIG. 4 illustrates a cross section wherein offset between apertures 3 are illustrated as well as one embodiment of a filter channel 78 is shown. It shall be noted that the multi-layer filter 1 as disclosed herein may have any number of layers and/or apertures 3.

[0088] FIG. 4 further illustrates how the filter channel openings 77 of the filter channel 78 can be arranged at different positions of the extension plane of the layers 2a, 2b, 2n such that different filter characteristics can be achieved. It should here be noted that in one embodiment the filter channel opening 77 of the intermediate layer is adjusted further than the other layers as one example.

[0089] FIG. 5 illustrates a multi-layer filter array 10 comprising multiple filter channels 78, each at least partly encompassed by apertures 3. FIG. 5 thus illustrates a clear advantage of the present solution wherein multiple filters can be arranged in an array.

[0090] FIG. 5 illustrates a 4×4 array filter but any number of rows and columns is possible and depends on what is suitable for the application area.

[0091] FIG. 6 illustrates the multi-layer filter array 10 of FIG. 5 and an antenna array 100 adapted to be attached to the multi-layer filter 10. The antenna array 100 is only an example embodiment and it is understood that many different forms of antennas can be used with the multi-layer filter array 10 as described herein.

[0092] FIG. 7 illustrates an assembled multi-layer filter 1 of the embodiment as shown in FIGS. 1 and 2.

[0093] FIG. 8 illustrates a cross-section of the embodiment as illustrated in FIGS. 1, 2 and 7 wherein the filter channel 78 is shown. The filter channel 78 might have different shape and form depending on which filter characteristics that are desired, for example if the multi-layer filter is designed as a low-pass, high-pass, or band-pass filter.

[0094] FIG. 9 illustrate examples of apertures 3 in layers 2a; 2b; . . . ; 2n. The apertures 3 may have different shape and form in different embodiments of the multi-layer filter and multi-layer filter array. It could in some embodiments also be a combination of apertures within a single filter or filter array. FIG. 9 further illustrates one example of a second aperture 3b and a second central surface portion 5b increasing the edge length of the aperture 3 even further. FIG. 9 further illustrates how the central surface portion 5 can be connected to the rest of the layer with for example one or two connection tabs 6.

[0095] FIG. 10 illustrates a transparent view wherein apertures 3 of two layers 2a, 2b, are visible showing one embodiment of an offset between apertures. The dashed lines describe the second layer 2b that is located behind the first layer 2a.

[0096] In general, for the embodiments as disclosed here in the apertures arranged around the filter channel opening can be arranged at multiple outside perimeters. I.e. in an embodiment two or more outside perimeters of EBG structure apertures 3 might be used instead of one.