A waveguide arrangement

TECHNICAL FIELD

The present disclosure relates to a waveguide arrangement comprising a first waveguide port, a second waveguide port and a waveguide conductor that extends between the waveguide ports.

BACKGROUND

Traditionally, microwave radios and radars are using waveguide components due to the low losses. There are waveguides ports used as interfaces to receivers, to transmitters and to antennas. These waveguide components are often injection molded, 3D printed in polymers, or manufactured in milled metal or cast metal. For all these examples, the materials are often surface-treated with silver, gold or copper to lower the insertion losses. Some materials such as for example aluminum may work to a sufficient extent without surface treatment. These solutions are common on S-, C-, X-, Ku- and Ka- bands. It is common that there are H- or E-bends in the design to connect the waveguide ports to the rest of the waveguide ports. Sometimes filters are realized using so-called comb elements in the form of posts within the waveguide, one example is a so-called interdigital filter or combline filter.

A waveguide arrangement typically consists of a trench embodiment introduced into, or through, a substrate, eventually completed by a top and bottom substrate to seal the waveguide cavity. A silicon-based waveguide arrangement will often be realized by defining the waveguide trench by means of etching. Such an etching process will inherently carry a manufacturing error relating to the etch angle. The deeper the trench that is etched, the larger the potential error in the manufacturing process.

A high-performance waveguide arrangement requires tight and repeatable process tolerances for the etching. Presently, there is a high probability that a resulting waveguide arrangement will suffer deviation from the desired exact mechanical definition, primarily due to CD (Critical Dimension) loss and sidewall etch deviations, where walls that are intended to be perfectly straight end up angled. The CD loss can be compensated for in the mask layout, but the deviation in sidewall angle from a perfect vertical wall cannot be easily achieved using optimization of the etch process.

It is therefore desired to provide a waveguide arrangement and manufacturing method that provides enhanced and repeatable process tolerances in order to achieve a device that is suitable for the intended application without need for individual tuning of each device after the manufacturing process.

SUMMARY The above object is achieved by means of a waveguide arrangement comprising a first waveguide port, a second waveguide port and a waveguide conductor that extends between the waveguide ports. The waveguide conductor has an extension and comprises at least one metallized electrically conducting inner wall. The waveguide arrangement is formed in a multilayer structure comprising two outer layers and at least one intermediate layer that is positioned between the outer layers and where at least one intermediate layer comprises at least one internal structure. At least two layers comprise the waveguide conductor and the layers mainly run along an H-plane of the waveguide conductor.

This means that the waveguide arrangement is formed in several layers that mainly run along an H-plane, where at least one intermediate layer comprises at least one internal structure. Building a waveguide arrangement in this way using a multi-layer structure will reduce the error caused by the wall angle and thereby ensure repeatable process tolerances where delicate internal structures can be formed in a reliable and repeatable manner. Furthermore, improved repeatability minimizes the need of individual tuning.

According to some aspects, each layer is formed in one piece of at least partly metallized silicon.

This means that the waveguide arrangement with the internal structures can be made by using well-known etching and metallization techniques.

According to some aspects, the at least one internal structure comprises an array of posts that extend along a waveguide inner width, the posts extending from one inner wall and ending before the opposite inner wall.

In this way, a combline filter or interdigital filter can be formed in the waveguide arrangement in a reliable and uncomplicated manner. The volume formed between the posts can hereby be reduced, such that a combline filter becomes smaller than traditional cavity filters.

According to some aspects, at least one more layer comprises further internal structures. As an example, at least one further internal structure comprises at least one ridge that extends along a waveguide inner width, extending from one inner wall to the opposite inner wall.

This means that one or more layers can be formed with one or more internal structures, providing a versatile waveguide arrangement

According to some aspects, the waveguide conductor comprises at least one bend, where at least one bend is realized in a stepped manner using the multi-layer structure. At least two different steps are formed in different layers. This provides an uncomplicated way to provide one or more bends in the waveguide arrangement.

According to some aspects, at least one waveguide port is in the form of a coaxial port, where the internal structures of at least one intermediate layer comprise at least one coaxial probe arrangement.

According to some aspects, each coaxial probe arrangement comprises a probe post and a coaxial probe that extends from the probe post and is adapted to extend via a corresponding probe aperture in an outer layer.

This means that many different types of waveguide ports are possible to form in the waveguide arrangement according to the present disclosure, such as for example coaxial ports.

By means of the present disclosure, different kinds of waveguide ports and combinations of these are enabled. It is also made possible to combine traditional waveguide filters and combline filters.

The above object is also achieved by means of methods associated with the above advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will now be described more in detail with reference to the appended drawings, where:

Figure 1 A shows a perspective view of a waveguide arrangement according to a first example;

Figure IB shows a cross-section side view of the waveguide arrangement according to the first example;

Figure 2 shows an exploded view of the waveguide arrangement according to the first example;

Figure 3 shows a cross-section view of the waveguide arrangement according to the first example;

Figure 4 shows a perspective view of a waveguide arrangement according to a second example;

Figure 5 shows an exploded view of the waveguide arrangement according to the second example; Figure 6A shows a first cross-section view of the waveguide arrangement according to the second example;

Figure 6B shows an enlarged part of Figure 6A;

Figure 7 shows a second cross-section view of the waveguide arrangement according to the second example;

Figure 8 shows a top view of two layers of the waveguide arrangement according to the second example;

Figure 9 shows a perspective view of a waveguide arrangement according to a third example;

Figure 10 shows an exploded view of the waveguide arrangement according to the third example;

Figure 11 shows two layers bonded together;

Figure 12A-12F show an example of how a waveguide arrangement with two coaxial ports is formed; and

Figure 13 is a flowchart illustrating methods according to the present disclosure.

DETAILED DESCRIPTION

Aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings. The different devices, systems, computer programs and methods disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

The terminology used herein is for describing aspects of the disclosure only and is not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

With reference to Figure 1 - Figure 3, illustrating a first example, there is a waveguide arrangement 100 having longitudinal extension L and comprising a first waveguide port 101, a second waveguide port 102 and a waveguide conductor 103 that extends between the waveguide ports 101, 102. Figure 1 A shows a perspective view of a waveguide arrangement 100, Figure IB shows a cross-section side view of the waveguide arrangement, Figure 2 shows an exploded view of the waveguide arrangement 100 and Figure 3 shows a cross-section view of the waveguide arrangement 100.

The waveguide conductor 103 has an extension E and comprises at least one metallized electrically conducting inner wall 104, 105, 106, 107, in this example four electrically conducting inner walls 104, 105, 106, 107, the waveguide conductor 103 having a rectangular cross-section.

The waveguide arrangement is formed in a multilayer structure 108 comprising two outer layers

109, 110 and at least one intermediate layer 111 that is positioned between the outer layers 109,

110. According to some aspects, the layers 109, 110, 111 are individually formed. At least one intermediate layer 111 comprises at least one internal structure 112a, 112b, 112c, 112d, 113, 114.

In this example, there are two outer layers 109, 110, a first outer layer 109 and a second outer layer 110, and one intermediate layer 111. The intermediate layer 111 comprises at least one internal structure 112a, 112b, 112c, 112d, 113, 114, at least two layers comprise the waveguide conductor 103 and the layers mainly run along an H-plane of the waveguide conductor 103.

This means an electrically conducting continuous inner wall can be formed by means of metallization.

This means that the waveguide arrangement 100 is formed in several layers that mainly run along an H-plane, where at least one intermediate layer 111 comprises at least one internal structure 112a, 112b, 112c, 112d, 113, 114. Building a waveguide arrangement 100 in this way, using a multi-layer structure, will reduce the error caused by wall angles and thereby ensure repeatable process tolerances where delicate internal structures can be formed in a reliable and repeatable manner. In this manner, for example, working irises in the H-plane are enabled. Furthermore, the present invention also enables working combline filter and/or interdigital filters to be formed in the waveguide arrangement in a reliable and uncomplicated manner.

Furthermore, improved repeatability minimizes the need of individual tuning, where tuning elements often incur undesired losses, which thus may be avoided by means of the present invention.

Also, the metallization allows the use of noble metals such as copper, silver and gold to be used as inner walls, which brings low losses. In this example, all layers 109, 110, 111 comprise the waveguide conductor 103 such that the intermediate layer 111 is sandwiched between the two outer layers 109, 110 which both have a U- shape. According to some aspects, at least one intermediate layer I l l is sandwiched between two U-shaped outer layers 109, 110, where at least one intermediate layer comprises internal structures. Examples of internal structures will be described in the following. The layers have main extensions in an H-plane. Each U-shaped outer layer 109, 110 may be individually formed, or formed from for example two or more layers that are bonded together.

According to some aspects and as in particular shown in Figure 2, the at least one internal structure comprises an array of posts 112a, 112b, 112c, 112d that extend along a waveguide inner width wi, the posts extending from one inner wall 104, 105 and ending before the opposite inner wall 105, 104. Here, four posts 112a, 112b, 112c, 112d are shown, but of course there can be less or more posts.

According to some aspects, the posts 112a, 112b, 112c, 112d run between the inner walls 104, 105 in an alternating manner as shown in Figure 2.

In this way, a combline filter or interdigital filter can be formed in the waveguide arrangement in a reliable and uncomplicated manner. The volume formed between the posts can hereby be reduced, such that a combline filter becomes smaller than traditional cavity filters.

This provides a novel type of waveguide arrangement assembly that confers a lot of advantages. Mainly, enhanced and repeatable process tolerances are provided, as well as a way to produce delicate internal structures in a reliable and repeatable manner.

According to some aspects, at least one waveguide port 102 is in the form of a coaxial port, where the internal structures of at least one intermediate layer 111 comprise at least one coaxial probe arrangement 113, 114. This means that in this context, the term “waveguide port” should be interpreted broadly and encompass different types of ports that connect to the waveguide conductor, for example the coaxial ports described here. According to some further aspects, each coaxial probe arrangement 113, 114 comprises a probe post 113 and a coaxial probe 114 that extends from the probe post 113 and is adapted to extend via a corresponding probe aperture 115 in the first outer layer 109. In this example, one waveguide port 102 is in the form of a coaxial port where the intermediate layer 111 comprises one coaxial probe arrangement 113, 114 according to the above.

This means that delicate internal structures such as posts that end before reaching an opposite inner wall and coaxial probe arrangements can be made in a reliable and repeatable manner. According to some aspects, each layer 109, 110, 111 is formed in one piece of at least partly metallized silicon. This means that the waveguide arrangement 100 with the internal structures 112a, 112b, 112c, 112d, 113, 114 can be made by using well-known etching and metallization techniques.

According to some aspects, as indicated above, the probe post 113 and the coaxial probe 114 are both formed in the intermediate layer 111, and is guided through the probe aperture 115 in the first outer layer 109 when these layers 109, 111 are mounted to each other.

According to some aspects, as an alternative, the probe post 113 is formed in the intermediate layer 111 and the coaxial probe 114 is formed in the first outer layer 109. The coaxial probe 114 is initially not completely separated from the probe aperture 115 in the first outer layer 109, and then these layers 109, 111 are mounted to each other. This process comprises bonding the probe 114 to the probe post 113 such the coaxial probe 114 becomes attached to the probe post 113. In a next step, the coaxial probe 114 is completely separated from the probe aperture 115 such that the coaxial probe 114 is no longer in contact with the rest of the first outer layer 109. Finally, the parts are metallized such that the coaxial probe 114 and the probe post 113 form one metallized part. In this case, the delicate maneuver of inserting the coaxial probe 114 into the probe aperture 115 is avoided.

A further alternative for forming coaxial ports will be described later with reference to Figure 11 and Figure 12.

According to some aspects, at least one outer layer 109, 110 comprises a waveguide conductor part 116, 117. Here, both outer layers 109, 110 comprise a corresponding waveguide conductor part 116, 117, such that each outer layers 109, 110 comprises a corresponding indent or tube part. This means that each outer layer 109, 110 comprises both an outer wall and an inner conductor part 116, 117, constituting an integrated part.

According to some aspects, generally, each intermediate layer 111 comprises a waveguide conductor part 121, and in this example, the intermediate layer 111 comprises a waveguide conductor part 121.

The first example has disclosed a waveguide arrangement 100 that has a first waveguide port 101 in the form of a waveguide opening that is positioned at an edge and faces a direction along the longitudinal extension L, while the second waveguide port, the coaxial port, is positioned perpendicular to the longitudinal extension L. Many different examples and combinations are of course possible, one will be discussed below with reference to Figure 4 - Figure 8. Figure 4 shows a perspective view of a waveguide arrangement according to a second example, Figure 5 shows an exploded view of the waveguide arrangement according to the second example, Figure 6A shows a first cross-section view of the waveguide arrangement according to the second example, Figure 6B shows an enlarged part of Figure 6A, Figure 7 shows a second cross-section view of the waveguide arrangement according to the second example, and Figure 8 shows a top view of two layers of the waveguide arrangement according to the second example.

Here there is a waveguide arrangement 400 comprising a first waveguide port 401, a second waveguide port 402 and a waveguide conductor 403 that extends between the waveguide ports 401, 402. The waveguide conductor 403 has an extension E, the waveguide conductor 403 having a rectangular cross-section with electrically conducting inner walls in the same way as for the first example. The layers mainly run along an H-plane of the waveguide conductor 403.

The waveguide arrangement is formed in a multilayer structure 408 comprising two outer layers 409, 410, a first outer layer 409 and a second outer layer 410, and one intermediate layer 411 that is positioned between the outer layers 409, 410. According to some aspects, the layers 409, 410, 411 are individually formed and comprise the waveguide conductor 403. According to some aspects and as in particular shown in Figure 5 and Figure 8, the internal structures comprised in the intermediate layer 411 comprise posts 412a, 412b, 412c, 412d arranged in the same way as in the first example.

The first port 401 is still in the form of a waveguide opening, but here the waveguide opening faces a direction that is perpendicular to the longitudinal extension L. According to some aspects, generally, this is enabled by the waveguide conductor 403 comprising at least one bend 419, where at least one bend 419 is realized in a stepped manner, where at least two different steps 425, 426, 427, 428 are formed in different layers 409, 410, 411. In Figure 6B, showing an enlarged part of Figure 6A, the stepped bend 419 is pointed out more in detail. In this example, there is one bend 419 with four steps 425, 426, 427, 428 formed in all layers 409, 411, 410.

The second port 402 is a coaxial port arranged in the same way as in the first example, where the intermediate layer 411 comprises a coaxial probe arrangement 413, 414. According to some further aspects, the coaxial probe arrangement 413, 414 comprises a probe post 413 and a coaxial probe 414 that extends from the probe post 413 and is adapted to extend via a corresponding probe aperture 415 in the first outer layer 409.

As discussed for the first example above, the coaxial probe 414 can alternatively be comprised in the first outer layer 409. Furthermore, both outer layers 409, 410 comprise a corresponding waveguide conductor part 416, 417, such that each outer layers 409, 410 comprises a corresponding indent or tube part. This means that each outer layer 409, 410 comprises both an outer wall and an inner conductor part 416, 417, constituting an integrated part. The intermediate layer 411 also comprises a waveguide conductor part 421.

According to some aspects, generally, at least one more layer 410 comprises further internal structures 420a, 420b, 420c. According to some further aspects, at least one further internal structure comprises at least one ridge 420a, 420b, 420c that extends along a waveguide inner width Wi, extending from one inner wall 404 to the opposite inner wall 405. In this example, the inner conductor part 417 of the second outer layer 410 comprises three ridges 420a, 420b, 420c that are positioned such that they run between the posts 412a, 412b, 412c, 412d in the intermediate layer 411. The posts 412a, 412b, 412c, 412d and the ridges 420a, 420b, 420c are shown to have a maximum height with a thickness of the corresponding layer 410, 411, but his is of course not important. There can also be more ridges at other positions than those shown.

As shown in Figure 7, showing a cross-section of Figure 6A, another advantage of the present layered assembly technique for forming the waveguide arrangement 400 is shown. In the case of the layers 409, 410, 411 being formed by etching processes, the walls may not run straight but at certain angles (p (one indicated in Figure 7). If the waveguide arrangement 400 had been formed in one layer, this angular deviation from a desired straight wall would have been significant, but since there are several layers 409, 410, 411 forming waveguide arrangement 400, this manufacturing error angle restarts for each layer and the resulting error is significantly reduced. It is to be noted that Figure 7 is exaggerated to visualize the above.

Figure 9 and Figure 10 illustrate a third example, here there is a waveguide arrangement 900 comprising a first waveguide port 901, a second waveguide port 902. The second waveguide port 902 is hidden in Figure 9, but has the same configuration as the waveguide port 901. A waveguide conductor 903 extends between the waveguide ports 901, 902 and has a rectangular cross-section with electrically conducting inner walls, and the layers mainly run along an H-plane (not shown) of the waveguide conductor 903 in the same way as for the first and second examples. The ports 901, 902 are both in the form of waveguide openings that face a direction along the longitudinal extension L.

The waveguide arrangement is formed in a multilayer structure 908 comprising two outer layers 909, 910, a first outer layer 909 and a second outer layer 910. The multilayer structure 908 comprises a first intermediate layer 91 la, a second intermediate layer 91 lb and a third intermediate layer 911c that is positioned between the first intermediate layer 911a and the second intermediate layer 911b. The intermediate layers 911a, 911b, 911c are positioned between the two outer layers 909, 910.

According to some aspects, the layers 909, 910, 911a, 911b, 911c are individually formed and bonded together to form the waveguide conductor 903. According to some aspects, and as in particular shown in Figure 10, the internal structures comprised in the third intermediate layer 911c comprise posts 912a, 912b, 912c, 912d arranged in the same way as in the first and second examples.

The two outer layers 909, 910 are plates that in this example, form a respective top and bottom of the waveguide arrangement 100 that seal a vertical dimension of the waveguide arrangement 100 that is perpendicular to the longitudinal extension L, while the intermediate layers 911a, 911b, 911c comprise corresponding inner conductor parts 921a, 921b, 921c. The first intermediate layer 911a and the second intermediate layer 911b are constituted by two parallel parts that are shown as separate parts, but these parts can of course be joined at some point. Two or more intermediate layers 911a, 911b, 911c may of course comprise internal structures. According to some aspects, the two outer layers 109, 110 may also comprise internal structures and/or conductor parts.

According to some aspects, each outer layer 909, 910 and the respective adjacent intermediate layers 91 la, 91 lb may form a U-shaped outer layer as the ones described above. These U-shaped outer layers can then be mounted such that one or more intermediate layers is sandwiched between them. The layer may be at least partly U-shaped depending on for example type of waveguide port. In the example described with reference to Figure 1-3, the outer layers are U-shaped until the coaxial port, where the U-shape is terminated. In the example described with reference to Figure 4-8, the outer layers are U-shaped until the ports such that the outer layers 409, 410 have a “bathtub-shape”, where that shape also is interrupted by the ridged 420a, 420b, 420c.

With reference to Figure 11 and Figure 12A-12F, a procedure for forming coaxial ports will be described for the waveguide arrangement 1100. The completed waveguide arrangement 1100 is illustrated in Figure 12F. With reference to Figure 11, the first intermediate layer 1111a and the third intermediate layer 1111c are bonded together, and a cross-section is shown in Figure 12A. Figure 12B and 12D-12F show the same section as the layers are processed and more layers added to form the multi-layer waveguide arrangement 1108.

Figure 12B illustrates how material has been removed from the first intermediate layer 1111a and the third intermediate layer 1111c such that a first port first probe part 1114a and a second port first probe part 1114’ a have been formed in the first intermediate layer 1111a, and how a plurality of posts 1112 not connected to a probe, a first probe post 1113 connected to the first port first probe part 1114a and a second probe post 1113’ connected to the second port first probe part 1114’a have been formed in the third intermediate layer 1111c. Furthermore, a first waveguide conductor part 1102 is formed in the first intermediate layer 1111a and a third waveguide conductor part 1104 is formed in the third intermediate layer 1111c. The first waveguide conductor part 1102 comprises the first probe parts 1114a, 1114’a and the third waveguide conductor part 1104 comprises the posts 1112, 1113, 1113’. Then, the first intermediate layer 1111a and the third intermediate layer 1111c are metallized.

In Figure 12C, the side of the first outer layer 1109 that is intended to face the first intermediate layer 1111a has been metallized such that a metal layer 1120 is formed, and thereafter metal has been removed Rl, R2 where material later is to be removed. In this way, metal end parts El, E2 are formed which are intended to contact the first port first probe part 1114a and the second port first probe part 1114’a.

In Figure 12D, the first outer layer 1109 has been bonded to the first intermediate layer 1111a.

In Figure 12E, material has been removed from the first outer layer 1109, for example from the side that faces away from the first intermediate layer 1111a, such that a first port second probe part 1114b and a second port second probe part 1114’b have been formed in the first outer layer 1109, the first port second probe part 1114b being a continuation of the first port first probe part 1114a and the second port second probe part 1114’b being a continuation of the second port first probe part 1114’a. The first outer layer 1109 is now metallized again such that electrical contact is made along the probe parts 1114a, 1114b; 1114’a, 1114’b that have been formed. Also, all other surfaces of the first outer layer 1109 are metallized such that a corresponding outer coaxial conductor 1121, 1121’ is formed.

At this stage, many different parts can be attached to the third intermediate layer 1111c, for example a PCB, a metal plate, antenna elements and/or other types of active and passive micro wave structures.

In this example, a completed waveguide arrangement according to the one shown in Figure 12F will be formed. In Figure 12F, the waveguide arrangement 1100 comprising the layer structure 1108 is shown just before the second intermediate layer 1111b and the second outer layer 1110 are added, as indicated with arrows Ai, A2.

This addition can be performed in several ways, for example the second intermediate layer 1111b and the second outer layer 1110 are completed and bonded together separately, before being bonded to the rest of the waveguide arrangement 1100 as indicated in Figure 12F. This means that the second intermediate layer 1111b can be bonded to the second outer layer 1110, and then material is removed from the second intermediate layer 1111b and the layers 1110, 1111b metallized such that a second waveguide conductor part 1103 is formed before bonding the second intermediate layer 1111b to the third intermediate layer 1111c. The second intermediate layer 1111b and the second outer layer 1110 form a U-shape or a “bathtub-shape”. The second intermediate layer 1111b and the second outer layer 1110 can be formed in an SOI (Silicon on Insulator) wafer as a starting material provided as two bonded silicon wafers with an oxide separation.

Other orders of assembly are of course conceivable, for example the second intermediate layer 1111b is bonded to the third intermediate layer 1111c, and the second outer layer 1110 is then bonded to the second intermediate layer 1111b. Some steps include that material is removed from the second intermediate layer 1111b and the layers 1111b, 1111c are metallized such that a second waveguide conductor part 1103 is formed, where these steps are performed before the second intermediate layer 1111b is bonded to the third intermediate layer 1111c. According to some aspects, material can be removed from the second intermediate layer 1111b before the second intermediate layer 111 lb is bonded to the third intermediate layer 1111c.

The above is intended to describe a further example of how one or more coaxial ports can be formed in a multi-layer waveguide arrangement according to the present disclosure. The posts are not necessary, and are shown for illustrative purposes. Other internal structures such as for example a plurality of ridges described above with reference to Figure 5 and 6A can also be included. The bonding makes the layers 1109, 1110, 1111a, 1111b, 1111c to be rigidly attached to each other, and the removal of material can be performed in many ways, for example by means of etching of the material that form the layers 1109, 1111a, 1111b, 1111c in which structures are formed. Material may be removed from a layer before or after that layer has been bonded to another layer. The procedure disclosed does not have to take place in the order described, but may be performed in any suitable order.

Metallization of the waveguide arrangement 1100 may be performed layer-wise, when two or more layers are bonded together, and/or when the complete layer structure 108 has been formed.

With reference to Figure 13, the present disclosure also relates to a method for forming a waveguide arrangement 100, 400. The method comprises providing S100 two outer layers 109, 110; 409, 410 and at least one intermediate layer 111, 411, the layers 109, 110, 111; 409, 410, 411 being formed in a substrate material, where each intermediate layer 111, 411 is adapted to be positioned between the outer layers 109, 110; 409, 410 to form a layer structure 108, 408. The method further comprises etching S200 a corresponding waveguide conductor part 116, 117, 121; 416, 417, 421 in at least one layer 109, 110, 111; 409, 410, 411, etching S300 at least one internal structure 112a, 112b, 112c, 112d, 113, 114; 412a, 412b, 412c, 412d; 413, 414 in at least one intermediate layer 111, 411, and bonding S400 the substrate layers 109, 110, 111; 409, 410, 411 together such that the waveguide arrangement 100, 400 is formed in a multilayer structure 108, 408. The waveguide conductor parts 116, 117, 121; 416, 417, 421 form a waveguide conductor 103, 403, where the layers 109, 110, 111; 409, 410, 411 mainly run along an H-plane of the waveguide conductor 103, 403. The method further comprises at least partly metallizing S500 the substrate layers 109, 110, 111; 409, 410, 411 such that metallized electrically conducting inner walls 104, 105, 106, 107 are formed. This means an electrically conducting continuous inner wall can be formed by means of metallization.

The method above may be performed in different ways, according to some aspects such that some steps can be performed in different orders. For example, the step of at least partly metallizing S500 the substrate layers 109, 110, 111; 409, 410, 411 can take place before the step of bonding S400 the substrate layers 109, 110, 111; 409, 410, 411 together. It is also conceivable that the step of at least partly metallizing S500 the substrate layers 109, 110, 111; 409, 410, 411 can take place both before and after the step of bonding S400 the substrate layers 109, 110, 111; 409, 410, 411 together.

According to some aspects, the at least one internal structure comprises an array of posts 112a, 112b, 112c, 112d; 412a, 412b, 412c, 412d that extend along a waveguide inner width wi, the posts extending from one inner wall 104, 105 and ending before the opposite inner wall 105, 104.

According to some aspects, at least one more layer 410 comprises further internal structures 420a, 420b, 420c, where at least one further internal structure comprises at least one ridge 420a, 420b, 420c that extends along a waveguide inner width Wi, extending from one inner wall 104 to the opposite inner wall 105.

According to some aspects, the method comprises forming all layers 109, 110; 409, 410; 909, 910; 111, 411; 911a, 911b, 911c individually and bonding them together.

The present disclosure is not limited to the above, but may vary freely within the scope of the appended claims. For example, all ports in the examples shown can of course be combined and arranged in any manner, for example one or more coaxial ports can be formed at an edge and face a direction along a longitudinal extension L. A waveguide port can also be positioned in a horizontal direction perpendicular to the longitudinal extension L. This is the case for all examples described. Ridges, posts and coaxial probe arrangements have been shown as examples of internal structures; these can of course be combined in any manner, and many other types of internal structures are of course conceivable. This is the case for all examples described.

The waveguide arrangement according to the present disclosure is normally a part of a larger assembly, and several waveguide arrangements may be stacked and/or connected in serial with intermediate components.

By means of the present disclosure, waveguide arrangements with relatively complicated internal structures that previously have been difficult to manufacture, can now be formed in a relatively uncomplicated an inexpensive manner with an increased degree of accuracy.

According to some aspects, at least one further internal structure comprises one or more ridges that extend perpendicular to a waveguide inner width wi.

According to some aspects, for all examples, at least one layer 109, 110; 409, 410; 909, 910; 111, 411; 911a, 911b, 911c is individually formed. In this context, individually formed means that a layer is formed from one piece of material, not formed from bonding two or more pieces of material together.

All Figures are of a schematically character, only being intended to illustrate the present invention, and not being intended to suggest actual proportions and/or measures.

As mentioned previously, the term “waveguide port” should be interpreted broadly and encompass different types of ports that work as interfaces that connect to the waveguide conductor. Other examples of a waveguide port is an interface to one or more antenna elements or an interface to another component such as a waveguide filter or an electronic component/arrangement. Even an interface to a termination, open circuit or short-circuit is also to be regarded as a waveguide port in this context.

According to some aspects, the waveguide arrangement can be regarded as a waveguide structure that is formed in a multilayer structure.