Waveguide component

Abstract

The invention relates to a waveguide component with a cavity for guiding a high-frequency wave, wherein the waveguide component is composed of one or more parts which are joined together to create at least one wall to which high-frequency waves are applied and which limits the cavity, wherein at least one connection element is provided which is designed and arranged to produce a high-frequency-capable connection between the parts forming said wall or sections of the part, wherein the at least one connection element completely or partially forms and / or is tangent to said wall of the cavity of the waveguide component and / or completely or partially projects into the cavity of the waveguide component, and wherein the connection element has one or more projections or is formed by same, which engage in at least one of the joined-together parts or sections of the part.

Description

[0001] Waveguide component

[0002] The present invention relates to a waveguide component having a cavity for guiding a high-frequency wave, wherein the waveguide component is composed of one or more parts which are joined together to produce at least one wall of the waveguide component which is exposed to high-frequency waves and which delimits the cavity, wherein at least one connecting element is provided which is designed and arranged in such a way as to produce a high-frequency-compatible connection between the parts or sections of the part forming said wall.

[0003] It is known from the state of the art to assemble waveguides from multiple components. For example, split-block arrangements are known in which two metal halves are milled in half and then assembled. This is also conceivable using injection-molded and metallized plastic halves and requires an adhesive, soldering, welding, screwing, and / or riveting process during assembly to enable a connection that is as completely sealed and, above all, mechanically gap-free as possible. A mechanically gap-free connection is desirable for state-of-the-art connections, as otherwise electromagnetic waves can escape from the gap and thus limit the functionality of the waveguide.

[0004] The known processes for connecting waveguide components usually prove to be disadvantageous because they can limit the waveguide's high-frequency functionality. For example, during soldering, a solder lump can inadvertently protrude into the waveguide. Welding can also create unwanted cavities that protrude into the waveguide, where they interact undesirably with the electromagnetic wave. The same problem also arises with adhesive bonding and other state-of-the-art processes.

[0005] Screws are known to be used for purely mechanical connections. To create a completely reliably closed mechanical gap at all relevant points of the transition between components, many screws are often required. On the other hand, distortion during tightening of one or more screws can cause such an undesirable mechanical gap at the high-frequency-relevant point of the transition, as the screwed components are then mechanically stressed.

[0006] It is also known in the prior art to accept a certain mechanical gap and still produce functional systems using resonant forms, such as electromagnetic bandgap structures (EBGs), for narrow bandwidth ranges. However, these structures have, among other disadvantages, a limited bandwidth and may also require precise gap dimensions, which is particularly problematic in large-scale production.

[0007] A mechanical gap, which can arise from the prior art methods, limits the design freedom and reliability, as well as the functionality of such waveguides. Against this background, the present invention is based on the object of further developing the aforementioned waveguide in such a way that an improved connection between two components of the waveguide is achieved, which can be reliably used, in particular, in series and mass production.

[0008] This object is achieved by the subject matter having the features of independent claim 1. Advantageous developments of the invention are the subject matter of the dependent claims.

[0009] It is then provided that the at least one connecting element forms and / or is tangent to the said wall of the cavity of the waveguide component and / or protrudes wholly or partly into the cavity of the waveguide component and that the connecting element has or is formed by one or more projections which engage in at least one of the joined parts or sections of the part.

[0010] The invention also encompasses the case where the connecting means is not formed integrally with the first component, i.e. is formed separately therefrom.

[0011] A high-frequency-compatible connection is preferably a connection that closes off the existing or to be created cavity of the waveguide component for the electromagnetic wave in such a way that the cavity effectively behaves like a waveguide without necessarily being completely sealed. For example, after the at least one or more parts of the waveguide have been joined together, the at least one connecting element can fully or partially represent the contour of the waveguide's inner wall and enable a closed contour in cross-section. This contour must, however, be closed in the direction of propagation, but not necessarily everywhere, so that in the area where the parts or sections of one part are joined, a kind of "garden fence" is created that "closes" the contact area in the longitudinal direction.In other words, it can be provided that a high-frequency-compatible connection is provided in the area of ​​the high-frequency-relevant contact point between one or more parts of the waveguide component, which eliminates the gap for an electromagnetic wave transmitted through the waveguide component, even if a gap is or may still be present mechanically. However, the invention also encompasses a gap-free design in the connection area.

[0012] The waveguide component can be, for example, a waveguide, an antenna, a part of a waveguide, or a part of an antenna. The term "waveguide component" therefore also encompasses, for example, a waveguide or an antenna per se.

[0013] Preferably, the waveguide component is assembled from several parts. It is also conceivable that it is just a single part, which is folded, bent, etc., and can thus be joined to form a waveguide component by connecting the free sections of the part.

[0014] The contour of the wall of the waveguide component can be incorporated entirely or partially into one of the parts. The contour of the wall of the waveguide component can also be distributed across several parts and, when assembled, form the intended shape.

[0015] Preferably, the connecting means is provided as a component of the waveguide component. It is also conceivable for the connecting element to be designed as a separate part.

[0016] Preferably, the connecting means comprises or consists of a stamped part, a notch, a blade, a screw, and / or a toothed tooth. However, it is also conceivable for it to be a rivet, screw, or pin. Preferably, the connecting means comprises a press-fit zone, a recess, and / or a protrusion, and / or the parts are connected to one another by a press fit.

[0017] Preferably, the one or more parts are connected to one another by a further connecting means or not by a further connecting means. It is thus conceivable that no further connecting means be present apart from the connecting means according to claim 1.

[0018] However, a further connecting means can also be provided, which is arranged separately from the part(s). This means that in this embodiment, the further connecting means is arranged such that it is not part of the conduction path of the high-frequency wave, but rather has no influence on it.

[0019] It is preferably provided that the further connecting means comprises or consists of a solder, a rivet, a screw and / or a nail.

[0020] A welding process can also be used that takes place before, after or during the joining process.

[0021] Preferably, the waveguide component or the part(s) comprise and / or consist of metal and / or plastic and / or metallization

[0022] Preferably, the waveguide component or the part(s) are manufactured at least partially by injection molding, an additive manufacturing process, in particular 3D printing, punching, deep drawing, shear cutting, laser cutting, and / or a compression molding process, and / or comprise or consist of a molded interconnect device. Preferably, the waveguide component is a component of a circuit board, an antenna, or an antenna array.

[0023] It is also conceivable that one or more parts is / are a circuit board.

[0024] The connection between the two or more parts of the waveguide component can be designed as a separate connecting element, e.g.: a stamped sheet, as one or more blades, serrations and / or free forms that are part of at least one part.

[0025] The one or more blades, toothings and / or free forms that are part of at least the part(s) can be pressed into each other, e.g. by a press-fit zone and / or a press fit.

[0026] Rivets, screws or nail-like connections can be used to make contact on a waveguide wall.

[0027] The part or parts preferably form, due to their shape, at least in part, a wall, in particular an inner wall, of the waveguide channel of the waveguide component.

[0028] The part(s) preferably have connecting means, such as teeth, press-fit zones, blades, etc., or a solderable connecting means, similar to, for example, the "legs" in dual inline packages for integrated circuits.

[0029] The connecting element may be a single part and / or mounted in the connection area or pre-assembled on at least one of the parts.

[0030] The connection created by the connecting means in the region of the waveguide component preferably establishes a high-frequency connection between the parts or the sections of a part to be connected and can interact with an electromagnetic wave guided in the waveguide component.

[0031] The parts may be made of or contain plastic and / or metal.

[0032] One or more of the parts can be designed as a printed circuit board.

[0033] The parts can be made of different materials or can comprise different materials. For example, the first part can be made of coated plastic and the second part can be made of sheet metal, particularly stamped sheet metal, or each can comprise either plastic or sheet metal.

[0034] One or more parts may have recess elements and / or connecting elements.

[0035] Preferably, no clean and / or flat contact surface is required on at least part of the connection.

[0036] The connection is preferably suitable for the mass market and cost-effective.

[0037] Preferably, gap problems no longer exist when joining split blocks. This is preferably achieved by interlocking the connecting elements and parts at least in places.

[0038] The waveguide component is preferably designed such that a high-frequency electromagnetic wave, in particular with a frequency above 3 MHz, can be guided at least in some areas.

[0039] It can also be provided that the waveguide component has more than one part and / or more than one connecting means. In particular, it is conceivable that a connection between the parts or sections of the part is established by more than one connecting means. Furthermore, it is also conceivable that the radio-frequency system comprises an antenna array consisting of several antennas, as well as an associated feed and / or distribution network.

[0040] Preferably, the connecting means comprises or is a contour produced by shear cutting and / or laser cutting and / or a screw. The screw can also be a microscrew. The screw can have a thread diameter between 0.1 mm and 3 mm, preferably between 0.5 mm and 2 mm, in particular between 1 mm and 2 mm.

[0041] The connecting element can be manufactured by forming, e.g. bending and / or shearing.

[0042] The component or part(s) are preferably a high-frequency and / or electrical component.

[0043] In the context of this invention, electrical preferably includes the terms electrical and / or electronic.

[0044] It is conceivable that the connecting means or the elements defining the connecting means touch or even cut into the cross-sectional geometry of the waveguide inner sides at one or more points.

[0045] In particular, it is also conceivable for the contour of the at least one connecting element facing the cavity of the waveguide component to be located at a distance of a maximum of 1 mm, preferably a maximum of 0.5 mm, and in particular a maximum of 0.25 mm from the inner side of said wall of the waveguide component facing the cavity. The connecting means preferably creates a mechanical and high-frequency-compatible connection using one technology and in one step. However, it is also conceivable to focus on the quality of signal transmission (electromagnetic focus) in the transition region and to implement the mechanical requirement elsewhere in the connection of the two parts using approaches known from the prior art.

[0046] The transition region is preferably stable and tolerant to displacements between the parts in one or more directions, particularly in the direction of the joint. Stable and tolerant preferably means that slight changes, for example in the range of up to a few hundred microns, or deviations from the ideal geometric fit and / or positioning do not lead to a malfunction of the waveguide component from an electromagnetic perspective, particularly in terms of signal transmission.

[0047] Preferably, one or more parts are connected via one or more connecting means

[0048] It is conceivable that the connecting means, the waveguide component, and / or the part(s) of the waveguide component have one or more holes. The connecting means and the one or more parts may also have other openings.

[0049] It is also conceivable, in particular, for recesses to be provided for the elements of the connecting means in at least one part of the waveguide component and / or the waveguide system. Such recesses can, in particular, also be provided on a printed circuit board. This can, for example, improve the fit and / or enhance the mechanical connection quality in terms of service life or strength.

[0050] It is preferably provided that at least a part of the waveguide component has a recess, wherein the recess is preferably designed and arranged in such a way as to enable an introduction of at least one region of the connecting means into the recess.

[0051] It is preferably provided that at least one element of the connecting means with at least one of its contours touches and / or intersects the line cross-section of the waveguide component and / or is part of the cross-sectional geometry.

[0052] It is preferably provided that the connecting means is designed as a flat sheet, similar to a blade, and has a thickness of less than 1 mm, preferably less than 600 pm and in particular less than or equal to 500 pm.

[0053] It is preferably provided that the at least one part and / or the connecting means have a chamfer and / or a, preferably gradual, change in shape in the region of the connection.

[0054] Preferably, it is provided that the connecting means comes into contact with the electromagnetic wave which is guided through the waveguide component in the vicinity of which the connecting means is arranged.

[0055] It is preferably provided that the connecting means projects into a part over a certain length, in particular measured in the direction of the joint, wherein said length is less than 10 mm, preferably less than 5 mm and in particular less than 1 mm.

[0056] Preferably, it is provided that the connecting means engages, protrudes and / or engages with the body of a part, not necessarily into the waveguide cross-section, but also merely the plastic body from which the waveguide component is made, in a toothed manner.

[0057] It is preferably provided that the connection consists of at least one and preferably several elements and these elements preferably imitate and / or replicate said waveguide channel entirely or partially with their contours facing the waveguide channel, or are arranged transversely to the propagation direction of the electromagnetic wave.

[0058] It is preferably provided that the connecting means forms the contour of a wall of the waveguide component that carries the transverse currents of the waveguide component and / or functions as such at at least one point of the waveguide cross-section.

[0059] Preferably, it is provided that the fit of the first component on the second component is not ideally aligned, but has an offset, wherein the offset is less than 1 mm, preferably less than 500 pm.

[0060] It is preferably provided that a gap, in particular an air gap, is present in the region of the connection.

[0061] Preferably, an expansion of the waveguide cross-section is provided in the region of the transition, in particular with the aim of reducing the requirements for the accuracy of fit.

[0062] The waveguide cross-section is preferably determined by the frequency. It is conceivable that the higher the intended frequency, the smaller the dimensions.

[0063] For the range from 60 to 110 GHz, the waveguide component preferably has a wide side of approximately 2.5 mm to 3.1 mm and a narrow side of 1.27 mm to 1.55 mm. However, this is not to be considered limiting. Waveguide components with other dimensions and / or with other frequency ranges are also encompassed by the invention.

[0064] It is conceivable that the connecting means comprises a plug contact, a press-in zone, and / or a barb. The connecting means can preferably be connected to the waveguide component through a bore in the waveguide component and a barb and / or a press-in zone of the connecting means, with the barb and / or the press-in zone engaging in a bore in the waveguide component.

[0065] The waveguide component and / or the connecting means in the connection area can be chamfered in terms of their shape and / or exhibit a, preferably gradual, change in shape. This can serve both the mechanical fit, assembly, and high-frequency function.

[0066] It is conceivable that the connecting element could be interlocked with the waveguide component and / or with a component, or could gradually merge into one another via interlocking. Preferably, appropriate recesses are already provided in the model of the waveguide component to improve mechanical strength, avoid unnecessary distortion during compression, and / or promote a precise fit during assembly, especially in large quantities in series production.

[0067] The connecting means can preferably be mounted and / or pre-assembled directly in one of the parts.

[0068] A hole in the connecting element allows the waveguide component to be connected to the connecting element, preferably temporarily. A hole in the connecting element allows two components to be connected in a mechanically stable and, in particular, temporary manner.

[0069] The connecting element can also be a rivet, screw, or pin. Preferably, the connecting means comprises or consists of steel, stainless steel, aluminum, brass, sheet metal, copper, iron, and / or a precious metal, and / or is metallized or non-metallized, and / or is electrically conductive or non-conductive, at least in certain areas. The connecting means can also comprise or consist of a non-conductive material.

[0070] It is preferably provided that the part or one of the parts comprises or consists of plastic and / or has been produced at least partially by injection molding, an additive manufacturing process and / or by milling and / or is metallized or not metallized.

[0071] Parts of the waveguide component and / or the connecting means can also be designed without metallization. This allows the waveguide component to be used for dielectric lines. The waveguide component can preferably be a waveguide.

[0072] Preferably, the connecting means is designed in such a way that heat can be transported between the parts.

[0073] It is conceivable that a welding process and / or soldering may take place before, during or after the parts are joined / assembled.

[0074] It is particularly conceivable that a coating is carried out before, during or especially after the joining, for example by means of galvanic or electroless processes.

[0075] The invention further relates to a high-frequency system comprising at least one waveguide component according to one of the preceding claims. This may be one or more circuit boards, antennas, or antenna arrays, or a part thereof. The invention also relates to a method for producing a waveguide and / or high-frequency system according to the invention.

[0076] It should be noted here that the terms "a" and "an" do not necessarily refer to exactly one of the elements, although this represents a possible embodiment, but can also refer to a plurality of the elements. Likewise, the use of the plural also includes the presence of the element in question in the singular, and conversely, the singular also encompasses several of the elements in question. Furthermore, all features of the invention described herein can be combined with one another as desired or claimed in isolation from one another.

[0077] Further advantages, features and effects of the present invention will become apparent from the following description of preferred embodiments and from the figures which show preferred embodiments of the invention.

[0078] A first embodiment relates to a waveguide in an antenna array for an automotive radar.

[0079] An initially flat sheet of metal is provided with several U-shaped grooves (in cross-section) that are open on one side through a pressing process or deep drawing. Further recesses or cutouts are also created along the grooves to serve the subsequent connection.

[0080] Radiating slot-shaped openings are created in another sheet of metal – for example, using a punching process – to form the radiating slots of the antennas. In addition, tabs are created by inserting U-shaped cut lines into the second sheet. The tabs are bent over and serve as connecting elements / connectors.

[0081] The two sheets are joined together – for example, by pressing – in such a way that the grooves in the first sheet, together with the second sheet, form cavities. The radiating slots in the second sheet are located in the areas that, together with the designated grooves in the first sheet, form a waveguide slot antenna. The areas where the waveguides feeding the antennas and the resulting distribution network are located do not necessarily have slots in the second sheet.

[0082] During assembly, the connecting elements are inserted into the recesses or cutouts provided along the grooves in the first sheet. Thus, where positioned, they close the cross-section of the waveguide and ensure a connection that is – from a high-frequency perspective – RF-compatible. This connection can, in particular, still have gaps or holes in the contact area along the waveguide contour. However, these gaps or holes no longer impair RF functionality.

[0083] Due to the contact created by the blades, a mechanical gap can also remain between the parts in the area of ​​the waveguide cross-section, thus enabling coarser manufacturing tolerances, which is particularly advantageous for series or mass production.

[0084] Due to its geometric complexity, one of the parts may be fully or partially additively manufactured. For example, using plastic 3D printing and subsequent metallic coating. It may also contain waveguides, waveguide components, and / or antennas even before assembly.

[0085] Figure 1 shows a perspective view of a waveguide according to the invention. The waveguide is constructed in two parts and has a cover part 10 and a bottom part 20. Both parts 10, 20 can be formed from sheet metal or made of a different material.

[0086] Part 20 is trough-shaped and has a bottom and two side walls. It is open at its ends. The cover part 10 and the lower part 20 together define the waveguide channel H for guiding the high-frequency wave.

[0087] Figure 2 shows the waveguide according to Figure 1 with a transparent cover part 10 and illustrates that the lower part 20 has recesses 30 which are spaced apart from one another in the longitudinal direction of the part 20 and which are located on both side walls of the part 20.

[0088] Figure 3 shows the embodiment according to Figure 1 with a transparent lower part and illustrates that there are projections 40 on the underside of the cover part 10 which, when the two parts are joined together, together with the recesses 30 form the connecting means in the sense of the present invention.

[0089] Figures 4, 5, and 6 show a cross-sectional view of the waveguide shown in Figure 1. These figures clearly show that the connecting means can be designed such that a gap 50 can remain between the two parts 10, 20 forming the waveguide. Figure 5 shows the cover part as transparent, and Figure 6 shows the lower part of the waveguide.

[0090] Figure 7 shows a longitudinal sectional view through the waveguide according to Figure 1 and illustrates the interlocking between the recesses 30 and the projections 40, which together form the connecting means of the joined waveguide.

[0091] Figure 8 shows the design of Figure 7 with the cover part shown transparently and Figure 9 with the lower part of the waveguide shown transparently.

[0092] Figure 10 shows a longitudinal sectional view of the shape of the projections 40 of the cover part, which have a downwardly projecting section that engages the recesses in the lower part. The illustrated shape of the projections results in the recesses visible in Figure 1 on the upper side of the cover part 10. The projections are created by inserting tabs into the cover part through U-shaped cutting lines. The resulting tabs are bent over and represent blades, i.e., projections as connecting elements / connecting means.

[0093] Figure 11 shows another embodiment of a waveguide according to the invention, in which slots are located in the cover part 10. Figure 12 shows the waveguide according to Figure 11 in plan view. The slots form radiating, slot-shaped openings—created, for example, by means of a punching process—which are intended to form the radiating slots of the antennas.

[0094] Figure 13 shows the waveguide according to Figure 11 in a perspective view with the cover part shown transparently and Figure 14 shows the waveguide with the lower part shown transparently.

[0095] Figure 15 shows the cover part with the downwardly projecting projections which form part of the connecting means with the lower part.

[0096] According to the exemplary embodiment, the connecting means 30, 40 of the waveguide establish a high-frequency connection between the parts 10 and 20 and interact with an electromagnetic wave guided in the waveguide.

[0097] In the embodiment shown here, the connecting means are integral components of the cover part 10 and the lower part 20. The invention also encompasses the case where this is not the case, but rather a separate connecting means is used for the parts 10, 20, such as screws, rivets, etc.

Claims

Patent claims 1. Waveguide component with a cavity for guiding a high-frequency wave, wherein the waveguide component is composed of one or more parts which are joined together to produce at least one wall of the waveguide component which is exposed to high-frequency waves and which delimits the cavity, wherein at least one connecting element is provided which is designed and arranged in such a way as to produce a high-frequency-compatible connection between the parts or sections of the part forming said wall, characterized in that the at least one connecting element wholly or partially forms and / or is tangent to and / or wholly or partially projects into the cavity of the waveguide component and in that the connecting element has or is formed by one or more projections which are inserted into at least one of the joined parts or sections.sections of the part.

2. Waveguide component according to claim 1, characterized in that the plurality of parts or sections of the part are joined together in a joining direction and that the projection(s) of the connecting element extend in this joining direction.

3. Waveguide component according to claim 1 or 2, characterized in that the cavity is filled with air or gas or evacuated.

4. Waveguide component according to one of the preceding claims, characterized in that the connecting element forms an integral part of the part(s) or is designed as a separate connecting element.

5. Waveguide component according to one of the preceding claims, characterized in that the connecting element is designed such that the connection between the parts or between the sections of the part is gap-free or with one or more gaps.

6. Waveguide component according to one of the preceding claims, characterized in that the contour or surface of the at least one connecting element facing the cavity of the waveguide component is located at a distance of maximum 1 mm, preferably of maximum 0.5 mm and in particular of maximum 0.25 mm from the inner side of said wall of the waveguide component facing the cavity.

7. Waveguide component according to one of the preceding claims, characterized in that the waveguide component is a waveguide, an antenna, a part of a waveguide or a part of an antenna.

8. Waveguide component according to one of the preceding claims, characterized in that the connecting element is designed such that the projection(s) engage positively in recesses of at least one of the joined parts or sections of the part.

9. Waveguide component according to one of the preceding claims, characterized in that the at least one connecting element is pre-assembled / attached to at least one of the parts of the waveguide component.

10. Waveguide component according to one of the preceding claims, characterized in that the spatial extent of the connecting element in the propagation direction of the wave guided in the cavity of the waveguide component is less than or greater than or equal to half a guided wavelength of the waveguide component.

11. Waveguide component according to one of the preceding claims, characterized in that a plurality of connecting elements are provided and that the distance between at least two connecting elements in the propagation direction of the waves guided in the cavity of the waveguide component is less than or equal to half a guided wavelength of the waveguide component.

12. Waveguide component according to one of the preceding claims, characterized in that the connecting element forms both an electrical and a mechanical connection between the parts or two regions of the part.

13. Waveguide component according to one of the preceding claims, characterized in that the connecting means comprises or consists of one or more of the following elements: stamped part, notch, blade, screw, pin, rivet, toothing tooth.

14. Waveguide component according to one of the preceding claims, characterized in that the connecting means has a press-in zone, a recess and / or a raised portion and / or that the plurality of parts or the sections of a part are connected to one another by a press fit.

15. Waveguide component according to one of the preceding claims, characterized in that the parts or the sections of the part are connected by a further connecting means, or that the parts or the sections of the part are not connected by a further connecting means which is designed separately from the parts or the sections of the part.

16. Waveguide component according to claim 15, characterized in that the further connecting means comprises or consists of a solder, a rivet, a screw and / or a nail and / or a welded joint.

17. Waveguide component according to one of the preceding claims, characterized in that the waveguide component and / or at least one of the assembled parts is produced by additive manufacturing processes or injection molding, die casting, or other casting processes or by deep drawing, punching, mechanical forming of metal sheets or metal parts or by means of photolithography and / or that one of the assembled parts is a printed circuit board.

18. Waveguide component according to one of the preceding claims, characterized in that the waveguide component and / or at least one of the joined parts comprises or consists of metal and / or plastic and / or a metallization.

19. Waveguide component according to one of the preceding claims, characterized in that the waveguide component and / or at least one of the assembled parts has been produced partially or completely by injection molding, an additive manufacturing process, in particular 3D printing, punching, deep drawing, shear cutting, laser cutting and / or a pressing process and / or has or consists of a molded interconnect device.

20. Waveguide component according to one of the preceding claims, characterized in that the waveguide component is part of a printed circuit board, an antenna or an antenna array.

21. Waveguide component according to one of the preceding claims, characterized in that the waveguide component is galvanically coated, in particular in such a way that all or some of the surfaces are coated in such a way that the effective surface roughness is reduced compared to a non-galvanically coated surface.

22. High-frequency system with at least one waveguide component according to one of the preceding claims.

23. High-frequency system according to claim 22, characterized in that it comprises one or more printed circuit boards, antennas or antenna arrays or a part thereof.

24. A method for producing a waveguide component according to one of claims 1 to 21 and / or a high-frequency system according to claim 22 or 23.

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