EP3451441B1 - Coaxial filter - Google Patents

Description

The invention relates to a coaxial filter which is constructed with very few different parts in order to facilitate manufacture.

Filters are always used in communications engineering and high frequency technology when only certain frequency components of a signal are to be further processed. In addition to high-pass and low-pass filters, there are also band-pass or band-stop filters. Filters can be implemented digitally or constructed using discrete components. The filters can be built on a printed circuit board or designed as coaxial filters in the form of milled or cast cavity structures. Filters with a coaxial design are mostly produced in a die-casting process, with fine-tuning being possible using additional screw-in tuning elements.

the U.S. 6,005,455 A describes an RF filter for base stations. The HF filter comprises a housing in which a receiving chamber for a resonator inner conductor arrangement is provided. The resonator inner conductor arrangement comprises a connecting web on which individual resonator inner conductors are electrically conductively connected by their first end and run away from one another at a distance from the latter. The connecting web is galvanically connected to the housing.

From the U.S. 5,225,799 A a microwave filter is known which is constructed in one piece. The structures that ultimately form the side walls, the base, the cover and the inner conductor of the resonator are punched from a common sheet metal. These structures are all integrally connected to one another. A bending process then takes place to form a housing structure. The resonator inner conductors protrude from a side wall into the receiving space.

the US 2007/084977 A1 describes a high frequency filter. The RF filter comprises a housing which delimits a receiving chamber. A resonator inner conductor arrangement is provided in this. The resonator inner conductor arrangement comprises a plurality of resonator inner conductors. One end of this resonator inner conductor can be galvanically connected to the housing. The individual resonator inner conductors are connected to one another via a connecting web.

From the U.S. 5,892,419 A a high-frequency filter is known which comprises a resonator inner conductor arrangement. This resonator inner conductor arrangement comprises a connecting web on which individual resonator inner conductors are arranged. The resonator inner conductor arrangement can be bent in a U-shape.

the U.S. 3,597,709 A describes a high frequency filter. It comprises two housings which are arranged one above the other and each delimit a receiving space. Both housings are separated by a partition which has coupling openings. In each housing, resonator inner conductors are provided in the respective receiving space, the resonator inner conductors being arranged on one side wall and extending to the opposite side wall.

the JP S58 166803 A describes a filter that consists of dielectric plates. These plates are glued to one another with their backs via a metallic carrier plate. Thus, the coupling windows formed on the rear sides of the panels overlap via a through hole drilled in the first panel. In this way, several resonators are connected in series.

Such a filter is, for example, from DE 10 2004 010 683 B3 known. However, such a filter has the disadvantage that the overall volume, in particular the height, is large. This leads to problems in some areas of application.

Another high frequency filter is from the DE 43 30 491 A1 known. This high-frequency filter comprises two circumferential frames that are placed on top of one another and glued together. Resonator inner conductors, which are glued to the surrounding frame, are inserted between the two surrounding frames. The two lid arrangements close the high frequency filter.

Disadvantage of the DE 43 30 491 A1 is that the structure requires the provision of a large number of individual parts, which overall does not lead to highly accurate, reproducible electrical properties during assembly.

It is therefore the object of the present invention to create a coaxial filter whose ratio of electrical properties to structural volume is improved. This filter should also be able to be constructed as simply and inexpensively as possible.

The object is achieved according to independent claim 1. The dependent claims advantageously contain further developments.

1. a) an der Stirnwand eines wannenförmigen Gehäuseelements ausgebildet, wenn das Gehäuse ein weiteres wannenförmiges Gehäuseelement umfasst; oder
2. b) an der Deckelanordnung ausgebildet, wenn das Gehäuse eine Deckelanordnung umfasst.

The coaxial filter according to the invention comprises a housing which delimits a common receiving space. The housing comprises an electrically conductive material and furthermore has a trough-shaped housing element which comprises side walls and an end wall. The end wall closes a space between the side walls on one side from the outside. The side walls are formed in one piece with the end wall. The housing also comprises a further trough-shaped housing element which comprises side walls, a further space between these side walls being closed on one side by a further end wall. The side walls are in turn formed in one piece with the end wall. Both trough-shaped housing elements are placed on top of one another, so that the side walls of both trough-shaped housing elements run between the two end walls and together delimit or define the receiving space. define which is formed by the two spaces. The housing can alternatively also comprise a cover arrangement instead of a further trough-shaped housing element, the side walls of the trough-shaped housing element running between the end wall and the cover arrangement and thereby delimiting the receiving space formed by the space. In this case, the cover arrangement closes the receiving space. The housing is preferably designed to be HF-tight. Furthermore, at least one resonator inner conductor arrangement embodied in one piece is provided, which is arranged in the receiving space and which preferably consists of a stamped and / or lasered sheet metal. The at least one resonator inner conductor arrangement comprises a plurality of resonator inner conductors, at least two or all of which lie in the same plane and have a first end and a second end spaced apart from the first end. The resonator inner conductors are aligned parallel or with one component predominantly parallel to the end wall or to the cover arrangement. The resonator inner conductor arrangement also comprises a connecting web, on which the individual resonator inner conductors are electrically conductively connected at their first end and run away from the latter at a distance from one another. The resonator inner conductor arrangement preferably consists exclusively of the plurality of resonator inner conductors and the connecting web. At least two immediately adjacent resonator inner conductors, which extend away from the common connecting web in the same direction, are in visual contact with one another over their entire length or over their predominant length, which enables direct coupling. This means that the housing is not adapted to the contour of the resonator inner conductor arrangement and extends into the space between two adjacent resonator inner conductors. The wording "entire length" is to be understood as the length from the first to the second end. The housing can then have a very simple geometry and is therefore simple and inexpensive to manufacture. Furthermore, at least one pedestal arrangement is provided, the at least one pedestal arrangement extending in the direction of the at least one resonator inner conductor arrangement and ending at a distance from the latter. The at least one platform arrangement is in one piece:

1. a) formed on the end wall of a trough-shaped housing element if the housing comprises a further trough-shaped housing element; or
2. b) formed on the cover assembly when the housing comprises a cover assembly.

The side walls and the end wall of the housing element consist of a cast and / or extrusion and / or milled part or include such a part. The resonator inner conductor of the at least one resonator inner conductor arrangement extend away from the connecting web on both sides. The connecting web is divided into different connecting web sections, the connecting web sections running offset to one another. The resonator inner conductor arrangement is screwed and / or clamped to the housing.

It is particularly advantageous that the housing can be manufactured more cheaply than that of the prior art. The use of at least one trough-shaped housing element is advantageous because it can be manufactured in advance, i.e. before final assembly, and because the tolerances with regard to the respective side walls together with the end wall are many times lower than the tolerances for the housing from the state of the technique. In this case, only inadequate manufacturing tolerances can be achieved by using two separate side frames and two separate cover arrangements together with an adhesive connection. The solution according to the invention also reduces the number of joining or contact or transition points between different housing elements and the resonator inner conductor arrangement, which can negatively affect the electrical properties (lower losses or intermodulation). The number of possible faults or defects is therefore reduced. The use of a further trough-shaped housing element allows a symmetrical structure, only a corresponding shape being required if the trough-shaped housing element is produced, for example, in a (pressure) casting process. Use with a cover arrangement is also advantageous because it enables a very flat housing to be realized. The use of the resonator inner conductor arrangement also facilitates production because all the resonator inner conductors are arranged on the common connecting web and the entire resonator inner conductor arrangement is manufactured in one piece. The resonator inner conductor arrangement can be produced in a separate process and measured in advance for its exact dimensions. Due to the flat structure of the resonator inner conductor arrangement, it is ideally suited for use in the housing described above. Particularly beneficial is that the coaxial filter is made up of only three parts, which means that the overall height is very low. The coaxial filter can be produced in a casting process, in particular in an (aluminum or zinc) die-casting process. The production can also take place in a milling process or in an extrusion process. Such a coaxial filter can be used in particular for outputs of 5 to 20 watts. The performance can also be lower or higher. The housing and / or the resonator inner conductor arrangement could also be made of plastic, which would then have to be provided with an electrically conductive layer.

The at least one resonator inner conductor arrangement preferably consists of a sheet metal which can be punched, lasered, milled, drilled and / or printed. The at least one resonator inner conductor arrangement can on the one hand be galvanically separated from the housing or galvanically connected to it. The second end of the resonator inner conductor is preferably kept at a distance from the housing, the resonator inner conductor arrangement, in particular the individual resonator inner conductor, running centrally through the receiving space and being equidistant from the end faces or the cover arrangement. The resonator inner conductor arrangement is in particular soldered and / or screwed and / or clamped to the housing, but not glued (non-adhesive). An eccentric course would also be possible.

The resonator inner conductor arrangement can provide a low-pass or band-pass or band-stop or high-pass characteristic. It can also be an interconnected filter with which several frequency ranges can be served. The coaxial filter can be used as a diplexer or multiplexer or duplexer.

The resonator inner conductor arrangement preferably has a homogeneous thickness. This is preferably greater than 0.2 mm, 0.4 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, but more preferably smaller than 5mm, 4mm, 3mm, 2mm, 1mm, 0.8mm, 0.6mm. The area of the top or bottom of the resonator inner conductor arrangement is many times (more than 3, 5, 7, 9, 11, 13, 15, 17, 19 times) larger than the side surface of the resonator inner conductor arrangement.

In a further advantageous embodiment, the coaxial filter comprises a conductive separating web, which arises on one side wall of both trough-shaped housing elements placed on top of one another if the housing comprises a further trough-shaped housing element, or on the one trough-shaped housing element if the housing comprises a cover arrangement and in the direction of the opposite one Sidewall runs. As a result, the receiving space is divided into two receiving chambers which are connected to one another via an opening. The common connecting web of the resonator inner conductor arrangement preferably rests on the separating web, so that the individual resonator inner conductors protrude into different receiving chambers. As a result, a duplexer with filter paths which are predominantly decoupled from one another can be created in a very advantageous manner.

Another embodiment according to the invention provides that an additional resonator inner conductor arrangement is formed, wherein the one resonator inner conductor arrangement is fastened to the end wall of the trough-shaped housing element and the further resonator inner conductor arrangement is fastened to the end wall of the further trough-shaped housing element (e.g. directly or via Platform arrangements or spacers). An additional trough-shaped housing element could also be provided, the end wall of the trough-shaped housing element being placed on the end faces of its side walls, which is closed with a cover arrangement, whereby a further receiving space is formed. The further resonator inner conductor arrangement is then arranged in this further receiving space. At least one coupling opening is made in the end wall of the trough-shaped housing element, which is closed with the cover arrangement, so that electrical coupling between the individual resonator inner conductor arrangements in the different receiving spaces is possible. As a result, the coaxial filter can be expanded as required in order to be able to attach additional coupling and decoupling devices.

Figur 1:

eine vereinfachte Darstellung des erfindungsgemäßen Koaxialfilter, welches ein wannenförmiges Gehäuseelement zeigt, in dem eine Resonator-Innenleiteranordnung angeordnet ist;

Figur 2:

eine weitere vereinfachte Darstellung des erfindungsgemäßen Koaxialfilter, welches eine andere Ausgestaltung der Resonator-Innenleiteranordnung zeigt, und bei welchem drei Ein- und/oder Auskoppelvorrichtungen bzw. Ein- und/oder Auskoppelanschlüsse sichtbar sind;

Figuren 3A bis 3D:

verschiedene Ausführungsformen einer Podestanordnung auf der die Resonator-Innenleiteranordnung aufliegt;

Figuren 4A bis 4J:

verschiedene Ausführungsformen der Resonator-Innenleiteranordnung;

Figuren 5A, 5B:

zwei verschiedene Ausführungsbeispiele des Gehäuses des erfindungsgemäßen Koaxialfilters;

Figur 6:

den Einsatz mehrerer übereinander angeordneter Resonator-Innenleiteranordnungen;

Figuren 7A, 7B:

den Einsatz eines Trennstegs, der den Aufnahmeraum in zwei Aufnahmekammern teilt;

Figuren 8A bis 8L:

verschiedene Befestigungsmöglichkeiten für die Resonator-Innenleiteranordnung ;

Figuren 8M, 8N:

verschiedene Möglichkeiten, um die kapazitive Kopplung zwischen dem Gehäuse und der Resonator-Innenleiteranordnung zu erhöhen; und

Figuren 8O bis 8S:

verschiedene Möglichkeiten wie zwei Resonator-Innenleiteranordnungen übereinander angeordnet und ausgerichtet sein können.

Various exemplary embodiments of the invention are described below by way of example with reference to the drawings. The same items have the same reference symbols. The corresponding figures in the drawings show in detail:

Figure 1:

a simplified representation of the coaxial filter according to the invention, which shows a trough-shaped housing element in which a resonator inner conductor arrangement is arranged;

Figure 2:

a further simplified representation of the coaxial filter according to the invention, which shows a different embodiment of the resonator inner conductor arrangement, and in which three coupling and / or decoupling devices or input and / or decoupling connections are visible;

Figures 3A to 3D:

various embodiments of a pedestal arrangement on which the resonator inner conductor arrangement rests;

Figures 4A to 4J:

various embodiments of the resonator inner conductor arrangement;

Figures 5A, 5B:

two different embodiments of the housing of the coaxial filter according to the invention;

Figure 6:

the use of several superimposed resonator inner conductor arrangements;

Figures 7A, 7B:

the use of a divider that divides the receiving space into two receiving chambers;

Figures 8A to 8L:

various mounting options for the resonator inner conductor arrangement;

Figures 8M, 8N:

various ways to increase the capacitive coupling between the housing and the resonator inner conductor arrangement; and

Figures 8O to 8S:

different possibilities of how two resonator inner conductor arrangements can be arranged and aligned one above the other.

Figure 1 shows a simplified representation of the coaxial filter 1 according to the invention. The coaxial filter 1 comprises a housing 2 which delimits a common receiving space 5. The housing 2 consists of an electrically conductive material and comprises a trough-shaped housing element 2a, which comprises side walls 3a ₁ , 3a ₂ , 3a ₃ and 3a ₄ . The trough-shaped housing element 2a also comprises an end wall 4a, all side walls 3a ₁ , 3a ₂ , 3a ₃ and 3a _{4 being formed in} one piece with the end wall 4a. A space 5a between the side walls 3a ₁ , 3a ₂ , 3a ₃ and 3a ₄ is closed on one side by the end wall 4a. The side walls 3a ₁ , 3a ₂ , 3a ₃ and 3a ₄ delimit the space 5a or receiving space 5 all around. The side walls 3a ₁ , 3a ₂ , 3a ₃ and 3a _{4 also} represent the outer walls of the housing 2 at the same time.

In this case, the trough-shaped housing element 2a has a rectangular outline, in particular a longitudinal section. The side walls 3a ₁ to 3a ₄ preferably run perpendicular to the end wall 4a. However, they could also run obliquely to the end wall 4a. In the exemplary embodiment shown, the individual side walls 4a ₁ to 4a ₄ run at right angles to one another. The corners formed in this way could, however, also be rounded. Other basic forms are also conceivable. Thus, the coaxial filter 1 can also be designed square, oval or circular in a plan view of a longitudinal section. The individual side walls 4a ₁ to 4a ₄ can also have a stepped profile, as shown in FIG Figure 2 is shown. The trough-shaped housing element 2a consists of a material or comprises a material that is electrically conductive.

In Figure 1 the open housing 2 is shown. For the correct operation of the coaxial filter 1, however, it must be closed. This can be done in two ways. In a first possibility it is provided that a further trough-shaped housing element 2b is used, which is preferably constructed identically to the trough-shaped housing element 2a already described. The further tub-shaped housing element 2b, which can be found in Figure 5A also includes (circumferential) side walls 3b ₁ , 3b ₂ , 3b ₃ and 3b ₄ and an end wall 4b with a further space 5b between the side walls 3bi, 3b ₂ , 3b ₃ and 3b ₄ on one side through the end wall 4b is completed. The side walls 3bi, 3b ₂ , 3b ₃ and 3b ₄ are formed in one piece with the end wall 4b. The end wall 4b of the further trough-shaped housing element 2b therefore closes off the further space 5b between the side walls 3b ₁ , 3b ₂ , 3b ₃ and 3b ₄ on one side (end face) thereof. The side walls 3b ₁ , 3b ₂ , 3b ₃ and 3b _{4 also} represent the outer walls of the housing 2 at the same time.

The two trough-shaped housing elements 2a, 2b are placed one on top of the other with their open sides. The end faces of the side walls 3a ₁ to 3a ₄ and 3bi to 3b _{4 of the} two trough-shaped housing elements 2a, 2b preferably touch one another. The side walls 3a ₁ to 3a ₄ and 3bi to 3b _{4 of} both trough-shaped housing elements 2a, 2b run between the respective end walls 4a, 4b, whereby the receiving space 5 is limited, which is formed by the two spaces 5a, 5b. Such a composite housing 2 can, for example, the Figure 5A can be removed. Both trough-shaped housing elements 2a, 2b are preferably screwed and / or soldered to one another. The housing elements 2a, 2b can also be connected to one another differently (galvanically). Depending on the requirements for shielding to the outside, the connection does not necessarily have to be galvanic. The housing elements 2a, 2b can also be connected in a moisture-tight manner.

Instead of a further trough-shaped housing element 2b, one trough-shaped housing element 2a can also be closed with a cover arrangement 2c, the side walls 3a ₁ to 3a ₄ running between the end wall 4a and the cover arrangement 2c and the receiving space 5, which is formed by the space 5a, limit. Such a structure of the housing 2 is for example in Figure 5B to recognize. The cover arrangement 2c is preferably designed in one piece and, like the trough-shaped housing element 2a, consists of an electrically conductive material. In principle, the cover arrangement 2c could also consist of a dielectric which is coated on at least one side with an electrically conductive layer. A cover arrangement 2c is preferably plate-shaped and does not delimit any space itself. It extends itself only in one plane.

In Figure 1 Furthermore, at least one resonator inner conductor arrangement 6, 6a embodied in one piece is provided, which is arranged in the receiving space 5. The at least one resonator inner conductor arrangement 6, 6a comprises several resonator inner conductors 7a, 7b, ... 7n with n ≥ 2, 3, 4, 5, 6, 7, 8, 9, 10 and n element of the natural numbers, the preferably all lie in the same plane. The resonator inner conductors 7a to 7n each include a first end 8 and a second end 9 spaced from the first end 8. The resonator inner conductors 7a to 7n run with one component parallel or predominantly parallel to an end wall 4a, 4b or to the cover arrangement 2c .

The at least one resonator inner conductor arrangement 6, 6a also comprises a (common) connecting web 10, on which the resonator inner conductors 7a to 7n are electrically conductively connected with their first end 8. The individual resonator inner conductors 7a to 7n run parallel to one another and parallel to at least one side wall 3a ₂ or 3a ₄ .

The resonator inner conductor arrangement 6, 6a is in particular free of a surrounding frame in which the multiple resonator inner conductors 7a, 7b,... 7n and the connecting web 10 are arranged and which is formed in one piece on the connecting web 10.

The connecting web 10 of the resonator inner conductor arrangement 6, 6a extends over more than 60%, 70%, 80%, 90% or 95% of the length of a side wall 3a ₁ , 3a ₂ , 3a ₃ and 3a ₄ , which also forms an outer wall, along and parallel to this. In particular, the receiving space 5 extends over the entire length and / or width of the coaxial filter 1 (minus the thickness of the respective side wall 3a ₁ , 3a ₂ , 3a ₃ and 3a ₄ ).

The individual resonator inner conductors 7a to 7n are spaced apart from one another by a predetermined distance. At least two adjacent resonator inner conductors 7a to 7n, which extend away from the connecting web 10 in the same direction, are in visual contact with one another over their entire length or over their predominant length (more than 50%, 60%, 70% or 80%). This means that the housing 2 is just not in the space immersed between two adjacent resonator inner conductors 7a to 7n, whereby the coupling between two adjacent resonator inner conductors 7a to 7n would be greatly reduced.

All resonator inner conductors 7a to 7n extend in Figure 1 away from the same side of the connecting web 10. The connecting web 10 preferably runs parallel to a side wall 3a ₁ or 3a _{3 of} the trough-shaped housing element 2a. The connecting web 10 is preferably arranged closer to a side wall 3a ₃ , to which it runs parallel or with one component predominantly parallel, than to another side wall 3a ₁ , to which it also runs parallel or predominantly parallel.

The connecting web has a length which preferably corresponds to more than 50%, 60%, 70%, 80% or 90% of the length of the side wall 3a ₁ or 3a ₃ , to which it runs parallel. The connecting web 10 is, however, preferably shorter than the corresponding side wall 3a ₁ or 3a ₃ to which it runs parallel.

The width of the connecting web 10 is preferably greater than the width of at least one or all of the resonator inner conductors 7a to 7n. However, it could also be the same or smaller.

In Figure 1 the width of the connecting web 10 at the beginning and at the end of the connecting web 10 is greater than in a region between the beginning and the end of the connecting web 10.

The resonator inner conductor arrangement 6, 6a consists of a stamped and / or lasered and / or bent and / or milled and / or printed sheet metal. A carrier material for the actual filter structure, as used in microstrip structures, is not required. This means that the resonator inner conductor arrangement 6, 6a is free of carrier material. Dispensing with a carrier material also reduces electrical losses, which improves the filter. In particular, the resonator inner conductor arrangement 6, 6a is free of circuit boards.

The resonator inner conductor arrangement 6, 6a is preferably made of a different material than the housing 2. It could also be made of the same material such as aluminum. However, the resonator inner conductor arrangement 6, 6a and the housing 2 do not consist of one and the same part or workpiece. They therefore consist of different workpieces. These are not formed in one piece with one another. These are produced in separate processes. The resonator inner conductor arrangement 6, 6a and the trough-shaped housing element 2a or 2b or the cover arrangement 2c are not produced from a common workpiece or part. This means that the resonator inner conductor arrangement 6, 6a is manufactured separately and inserted into the receiving space 5 of the housing 2. The insertion of the resonator inner conductor arrangement 6, 6a into the one trough-shaped housing element 2a is only possible via an opening which is closed by the further trough-shaped housing element 2b or the cover arrangement 2c. All other openings for insertion are closed by the side walls 3a ₁ , 3a ₂ , 3a ₃ and 3a ₄ and the end wall 4a.

The resonator inner conductor arrangement 6, 6a is held at a distance from the end faces 4a, 4b and the cover arrangement 2c. In particular, the resonator inner conductors 7a to 7n are kept at a distance from the housing 2, in particular from the end walls 4a, 4b or the cover arrangement 2c.

The resonator inner conductor arrangement 6, 6a is arranged in the receiving space 5 which is delimited _{directly by the side walls 3a 1} , 3a ₂ , 3a ₃ and 3a _{4 or 3bi, 3b 2} , 3b ₃ and 3b ₄ . The receiving space 5 always includes boundary walls, which are the side walls 3a ₁ , 3a ₂ , 3a ₃ and 3a ₄ or 3bi, 3b ₂ , 3b ₃ and 3b ₄ , which also represent the outer walls of the housing 2.

As will be explained later, the at least one resonator inner conductor arrangement 6, 6a is preferably soldered and / or screwed and / or clamped to the housing 2. This is preferably a galvanic connection. But this is not mandatory. The resonator inner conductor arrangement 6, 6a can also rest on a pedestal arrangement 11. Such a pedestal arrangement 11 is in view of Figures 3A to 3D explained in more detail. In the Figures 3A and 3B the pedestal arrangement 11 comprises a plurality of individual pedestals spaced apart from one another. The pedestal arrangement 11 comprises a dielectric material and / or an electrically conductive material. In principle, the dielectric material could also be coated with an electrically conductive layer or vice versa be. In Figure 3A the pedestal arrangement 11, which consists of several individual pedestals which have a round shape in cross section, is formed in one piece on at least one end wall 4a, 4b. The individual platforms are arranged at a distance from the side walls 3a ₁ , 3a ₂ , 3a ₃ , 3a ₄ . In principle, it could also be formed on the cover arrangement 2c. The individual platforms are preferably arranged at the same distance from one another. The resonator inner conductor arrangement 6, 6a preferably does not touch the housing 2 and is only held at a distance from the housing 2 by the pedestal arrangement 11.

In Figure 3B these individual platforms also have an extension in the direction of the respective side wall 3a ₁ to 3a ₄ or 3b ₁ to 3b ₄ . In the Figure 3B The pedestal arrangement 11 shown is preferably formed in one piece with the corresponding side wall 3a ₁ to 3a ₄ or 3bi to 3b _{4 of} the at least one trough-shaped housing element 2a or 2b. It can also be designed in one piece on the corresponding end wall 4a or 4b. In this case, the pedestal arrangement 11 consists of the same electrically conductive material from which the trough-shaped housing elements 4a, 4b also consist.

In Figure 3C the pedestal arrangement 11 comprises a continuous pedestal which extends along at least 50% of the length of a side wall 3a ₁ or 3a ₃ or 3b ₁ , 3b ₃ . The continuous platform extends parallel or with one component predominantly parallel to the corresponding side wall 3a ₁ , 3a ₃ or 3b ₁ , 3b ₃ .

Figure 3D combines the exemplary embodiments Figure 3B and 3C . The continuous platform Figure 3C , which is arranged at a distance from the side walls 3a ₁ to 3a ₄ or 3bi to 3b ₄ , is additionally galvanically and in particular _{integrally connected to at least one side wall 3a 1} to 3a ₄ or 3bi to 3b ₄ via connecting segments. This platform arrangement 11 is also preferably connected in one piece with the end wall 4a and / or at least one side wall 3a ₁ to 3a _{4 of} the trough-shaped housing element 2a or with the end wall 4b and / or at least one side wall 3bi to 3b _{4 of} the further trough-shaped housing element 2b.

The at least one resonator inner conductor arrangement 6, 6a rests on the at least one pedestal arrangement 11. The resonator inner conductor arrangement is preferably located 6 only on its connecting web 10 on the pedestal arrangement 11. This fact is for example in Figure 1 shown.

Figure 2 shows a further embodiment of the coaxial filter 1 according to the invention run in one plane to each other. This means that the individual connecting web sections 10a to 10n are _{spaced at different distances from the side walls 3a 1} , 3a ₃ or 3b ₁ , 3b ₃ , to which they run parallel or with one component predominantly parallel. It is also shown that at least two or all of the resonator inner conductors 7a to 7n, which, starting from the common connecting web 10, extend in the same direction, are of different lengths.

The resonator inner conductor 7a to 7n of the at least one resonator inner conductor arrangement 6, 6a extend in Figure 2 away from the connecting web 6 on both sides.

The resonator inner conductor arrangement 6, 6a lies in Figure 2 not on their connecting web 10 on the at least one pedestal arrangement 11, but on the second end 9 of those resonator inner conductors 7a to 7n which extend along a direction away from the common connecting web 10. However, it would also be possible for the connecting web 10 to rest on the at least one pedestal arrangement 11.

The resonator inner conductors 7a to 7n, which extend along one direction from the common connecting web 10, are spaced along a partial length of the connecting web 10 at different distances from the side wall 3a ₁ or 3bi to which they run, whereas they are spaced over a different partial length of the connecting web 10, from which they protrude, are _{spaced equidistant from the corresponding side wall 3a 1} or 3bi to which they run. Furthermore, those resonator inner conductors 7a to 7n, which are on another side of the common connecting web 10 in the direction of corresponding side wall 3a ₃ or 3b ₃ extend away, equidistant from this side wall 3a ₃ or 3b ₃ .

In Figure 2 a first, a second and a third coupling and / or decoupling device 12a, 12b and 12c are also provided, which are arranged at different points on the housing 2 and protrude from outside the housing 2 into the receiving space 5 and a capacitive or inductive or galvanic or produce predominantly capacitive or predominantly inductive or predominantly galvanic coupling to different resonator inner conductors 7a to 7n of the at least one resonator inner conductor arrangement 6, 6a.

Two of these coupling and / or decoupling devices 12a, 12b pass through a side wall 3a ₁ to 3a ₄ or 3b ₁ to 3b ₄ , whereas the third coupling and / or decoupling device 12c passes through an end wall 4a or 4b or the cover arrangement 2c. The first and second coupling and / or decoupling devices 12a, 12b are preferably coupled to the resonator inner conductors 7a, 7n, which are arranged at the beginning and at the end of the common connecting web 10. The third coupling and / or decoupling device 12c, which is preferably arranged perpendicular to the other coupling and / or decoupling devices 12a, 12b, is coupled to a resonator inner conductor which is located between the outermost resonator inner conductors 7a, 7n (in particular in the middle).

The distance between the individual coupling and / or decoupling devices 12a, 12b, 12c from the respective resonator inner conductor is preferably less than 5 cm, 4 cm, 3 cm, 2 cm, 1 cm, 0.5 cm. The coaxial filter 1 preferably works as a duplex filter.

The coupling and / or decoupling devices 12a, 12b, 12c can also be referred to as coupling and / or decoupling connections 12a, 12b, 12c. These are preferably sockets or plugs, which are placed on the housing 2 from the outside in particular and are screwed to it. Preferably, no printed circuit board is arranged between the coupling and / or decoupling devices 12a, 12b, 12c and the at least one resonator inner conductor arrangement 6, 6a.

In the following, the Figures 4A to 4J received, which show different embodiments of the resonator inner conductor arrangement 6, 6a.

At least one or all of the resonator inner conductors 7a to 7n of the at least one resonator inner conductor arrangement 6, 6a extend obliquely away from the common connecting web 10. The smaller angle α between the resonator inner conductors 7a to 7n and the common connecting web 10 has a size of more than 10 °, 20 °, 30 °, 40 °, 50 °, 60 °, 70 °, 80 °, but of less than 85 °, 75 °, 65 °, 55 °, 45 °, 35 °, 25 °, 15 °, 5 °. Each of the resonator inner conductors 7a to 7n can be divided into individual sections, which in turn run towards one another at an angle. In this case the corresponding inner conductor of the resonator would be kinked. However, all of these sections run at an angle of less than 90 ° to the connecting web 10.

In Figure 4B the resonator inner conductors 7a to 7n run away from the connecting web 10 at right angles. They are all the same length. The second end 9 of at least one or all of the resonator inner conductors 7a to 7n is angled (for example 90 °). The angled section preferably runs parallel to the side wall 3a _{1 or 3a 3} or 3bi or 3b ₃ , in the direction of which the individual resonator inner conductors 7a to 7n extend from the common connecting web 10. The angling enables the electrically effective length of the resonator inner conductors 7a to 7n, which also determine the corresponding resonance frequencies and thus the frequency range of the coaxial filter 1, to remain the same, while the side walls 3a ₂ and 3a ₄ (or 3b ₂ and 3b ₄ ) are shorter can be and the installation space of the coaxial filter 1 can be reduced in this dimension.

According to Figure 4B the resonator inner conductors 7a to 7n have an L-shape or are approximated to such a shape. The angled section runs in the same direction in all resonator inner conductors. The angled section of two adjacent resonator inner conductors 7a to 7n could also point to the respectively adjacent section, as shown in FIG Figure 4I is shown. This creates an increased (capacitive) coupling at the second end 9 of two adjacent resonator inner conductors 7a to 7n. The two ends 9 of two adjacent resonator inner conductors 7a to 7n therefore run towards one another.

In principle, it would also be possible for the angled sections with the second end 9 of the resonator inner conductor 7a to 7n to also run at an angle not equal to 90 ° with respect to the remaining section of the resonator inner conductor 7a to 7n.

In Figure 4C it is shown that the second end 9 of at least one, preferably all of the resonator inner conductors 7a to 7n is double-angled and the corresponding resonator inner conductor 7a to 7n in particular has a T-shape or approximates such a shape. Both sections of the resonator inner conductor 7a to 7n therefore run in the direction of two opposing side walls 3a ₂ , 3a ₄ and 3b ₂ , 3b _4, respectively. As a result, not only is the capacitive coupling between the individual adjacent resonator inner conductors 7a to 7n increased, but the capacitive coupling to the housing 2 is also increased.

In Figure 4D it is also shown that the second end 9 of at least one or all of the resonator inner conductors 7a to 7n has a double-angled shape. In this case, the resonator inner conductors 7a to 7n have a U-shape or are approximated to such a shape. This means that the second end 9 of the resonator inner conductor runs back in the direction of the first end 8. This not only increases the electrical length of the individual resonator inner conductor. At the same time, the coupling between two adjacent resonator inner conductors 7a to 7n and the coupling to the housing 2 are also increased.

In Figure 4E it is shown that the second end 9 of one or all of the resonator inner conductors 7a to 7n has an enlarged section. In particular, the second end 9 has an enlarged width which is circular in plan view or at least approximates a circular shape. The second end 9 can also be square or hexagonal or otherwise widened.

In Figure 4F a resonator inner conductor arrangement 6, 6a is shown, through which the coaxial filter works as a bandstop filter. At least two resonator inner conductors 7a to 7n or all resonator inner conductors 7a to 7n of the at least one resonator inner conductor arrangement 6, 6a have a width over a first partial length 13a, preferably starting at the first end 8, than over a second partial length 13b, which preferably ends at the second end 9. Both partial lengths 13a, 13b together preferably result in the total length of the resonator inner conductor 7a to 7n. The first partial length 13a can be of different lengths in at least two or all resonator inner conductors 7a to 7n. The same can also apply to the second partial length 13b. The first partial length 13a or the second partial length 13b can also be of the same length for all resonator inner conductors 7a to 7n. The resonator inner conductor 7a to 7n is approximately more than 1.5 or 2 or 2.5 or 3 or 3.5 or 4 times as wide over the second partial length 13b as in the case of the first partial length 13a.

In principle, it also applies that the common connecting web 10 is approximately as wide as the resonator inner conductor 7a to 7n. The wording "approximately" is to be understood to include a deviation of less than 25%, 20%, 15%, 10% or less than 5%.

Figure 4G shows a resonator inner conductor arrangement 6, 6a, by means of which the coaxial filter 1 can be operated as a low-pass filter. The at least one resonator inner conductor arrangement 6, 6a is constructed mirror-symmetrically in this case, the mirror axis running through the connecting web 10 and the connecting web 10 being several times narrower than the resonator inner conductors 7a to 7n. Such a mirror-symmetrical arrangement means that the resonator inner conductors 7a to 7n run on two sides from the common connecting web 10 in the direction of the opposite side wall 3a ₁ , 3a ₃ or 3b ₁ , 3b ₃ . The length of at least two resonator inner conductors 7a to 7n is different. The same also applies to the width of at least two resonator inner conductors 7a to 7n. The distance between two adjacent resonator inner conductors 7a to 7n can also be different. A structure that is not mirror-symmetrical would also be possible. The resonator inner conductor arrangement 6, 6a rests on a pedestal arrangement 11, not shown, which in this case consists of a dielectric material or comprises such a material.

The structure of the resonator inner conductor arrangement 6, 6a in Figure 4H essentially corresponds to the one from Figure 2 . The resonator inner conductor arrangement 6, 6a lies on the second end 9 of its resonator inner conductor 7a to 7n on the pedestal arrangement 11. The common connecting web 10 does not run through a straight line here, but is divided into connecting web sections 10a to 10n which are offset from one another. Figure 4J shows a cross-coupling between two non-adjacent resonator inner conductors 7a to 7n. In this case, a capacitive coupling is shown. The capacitive coupling is formed by a coupling element 14 which has at least two capacitive coupling surfaces 14a, 14b that are galvanically connected to one another. Each of these capacitive coupling surfaces 14a 14b preferably runs parallel or with one component predominantly parallel to the respective resonator inner conductor 7a to 7n. The coupling surfaces 14a, 14b are preferably closer to the second end 9 of the respective resonator inner conductor 7a to 7n than to the first end 8. The capacitive coupling surfaces 14a, 14b are between the resonator inner conductor 7a to 7n and the respective end wall 4a, 4b or the cover arrangement 2c. The coupling element 14 is galvanically separated from the resonator inner conductors 7 a to 7 n and the housing 2. A dielectric, on which the capacitive coupling surfaces 14a, 14b rest, can also be arranged between the capacitive coupling surfaces 14a, 14b and the resonator inner conductors 7a to 7n.

An inductive coupling would also be possible, this being preferably formed by a coupling rod (not shown). This would then be galvanically connected to two non-adjacent resonator inner conductors 7a to 7n, for example soldered. The arrangement would be the same as for the coupling element 14.

An inductive coupling between two adjacent resonator inner conductors 7a to 7n could also take place in that the connecting web 10 between these two resonator inner conductors 7a to 7n is wider than between two other resonator inner conductors 7a to 7n.

A coupling between two adjacent resonator inner conductors 7a to 7n generally exists both via their line of sight and via the corresponding part of the connecting web 10. The coupling can also be varied, for example, by changing the distances between the adjacent resonator inner conductors 7a to 7n or by varying the position (closer to the base point or closer to the open end) or by varying the shape (for example thinner or thicker) of the respective connecting web section 10a to 10n.

Figure 6 shows a further embodiment of the coaxial filter 1 according to the invention. In addition to the trough-shaped housing element 2a, the receiving space 5 of which is closed by the end wall 4a and the side walls 3a ₁ to 3a ₄ and the cover arrangement 2c, the coaxial filter 1 also includes an additional trough-shaped housing element 2b. This additional trough-shaped housing element 2b is constructed like the trough-shaped housing element 2a already described. The space 5b, which is delimited by the side walls 3bi to 3b ₄ , is additionally delimited by the end wall 4b and the end wall 4a of the trough-shaped housing element 2a lying above it. A resonator inner conductor arrangement 6, 6a, 6b is arranged in each of the two spaces 5a, 5b. The end wall 4a of the trough-shaped housing element 2a, which separates the two spaces 5a, 5b from one another, preferably comprises a coupling opening 15 (see FIG. Figure 8P ), whereby the individual resonator inner conductor arrangements 6, 6a, 6b are partially coupled to one another.

the Figures 7A and 7B show a further embodiment of the coaxial filter 1 according to the invention. In the event that two trough-shaped housing elements 2a, 2b are used, which together delimit the receiving space 5, an electrically conductive separating web 20 extends from a side wall 3a ₁ to 3a ₄ or 3b ₁ to 3b ₄ in the direction of an opposite side wall 3a ₁ to 3a ₄ or 3b ₁ to 3b ₄ and ends there with the formation of an opening 21 with this, whereby the receiving space 5 in at least a first receiving chamber 5 ₁ and in a second receiving chamber 5 ₂ and the , the opening 21 connecting at least two receiving chambers 5 ₁ , 5 _{2 is divided.} The separating web 20 is preferably formed in one piece with the corresponding trough-shaped housing element 2a, 2b and is also electrically conductive. The individual receiving _{chambers 5 1} , 5 ₂ are connected or coupled to one another directly via the opening 21 and without the interposition of a further chamber. The opening 21 is preferably free of parts of the resonator inner conductor arrangement 6, 6a, 6b, such as, for example, the resonator inner conductors 7a to 7n. The opening 21 preferably extends over the entire height of the receiving space 5 or preferably at least up to the respective end wall 4a, 4b.

In the event that only a trough-shaped housing element 2a is used, which is closed with the cover arrangement 2c and the receiving space 5, this has a separating web 20, which runs from a side wall 3a ₁ to 3a ₄ in the direction of the opposite side wall 3a ₁ to 3a ₄ and ends at a distance from this, forming an opening 21. Here, too, the separating web 20 is electrically conductive, preferably connected in one piece to the side wall _{3 a 1} to _{3 a 4} .

The common connecting web 10 preferably rests on the separating web 20. The individual resonator inner conductors 7a to 7n of the at least one resonator inner conductor arrangement 10 then extend into the first and second receiving chambers 5 ₁ , 5 _{2 of} the receiving space 5.

When using two trough-shaped housing elements 2a, 2b, the common connecting web 10 is preferably arranged between the two separating webs 20 and further preferably pressed and / or screwed and / or soldered to it. Figure 7A shows a longitudinal section through a trough-shaped housing element 2a, 2b, whereas Figure 7B shows a plan view of a trough-shaped housing element 2a or 2b, on the separating web of which the resonator inner conductor arrangement 6, 6a is placed. The individual resonator inner conductors 7a to 7n extend away from the common connecting web 10 in two different directions and end in the first and in the second receiving chamber 5 ₁ , 5 _{2 of} the receiving space 5.

In the event that only one trough-shaped housing element 2a is used, the common connecting web 10 is preferably arranged between the separating web 20 and the cover arrangement 2c, more preferably clamped or pressed and / or soldered and / or screwed to them. The first end 8 of the respective resonator inner conductors 7a to 7n comprises, for example, a segment which is bent in the direction of the end wall 4a so that the resonator inner conductors 7a to 7n run over the major part of their length at a predetermined distance from the cover arrangement 2c . The distance from the cover arrangement 2c is preferably more than 10% or 20% or 30% or 40% of the distance between the end face 4a and the cover arrangement 2c.

In the Figures 8A through 8L the fastening of the resonator inner conductor arrangement 6, 6a in the housing 2 is explained in more detail.

In Figure 8A it is shown that the resonator inner conductor arrangement 6, 6a is galvanically connected to the housing 2. Figure 8A shows a housing 2, which consists of two trough-shaped housing elements 2a, 2b, the side walls 3a ₁ to 3a ₄ and 3bi to 3b _{4 of} which are placed on top of one another and are surrounded by the respective end walls 4a, 4b. It is true that a gap (right part) is still shown between the two trough-shaped housing elements 2a, 2b. This, however, serves more for illustration purposes, in order to emphasize that these two trough-shaped housing elements 4a, 4b are not formed in one piece with one another. The resonator inner conductor arrangement 6, 6a runs centrally through the receiving space 5. This is to be understood as meaning that it is spaced essentially the same distance from the two end walls 4a, 4b. The wording "approximately" means that a difference of less than 10% or less than 5% is preferably included. An eccentric course would also be conceivable.

In Figure 8A the at least one resonator inner conductor arrangement 6, 6a is clamped and / or screwed between the two trough-shaped housing elements 2a, 2b. More precisely, a platform arrangement 11 extends from each trough-shaped housing element 2a, 2b into the receiving space 5. The resonator inner conductor arrangement 6, 6a is arranged between the two pedestal arrangements 11. For this purpose, the platform arrangements 11 have corresponding support shoulders 25, on which the resonator inner conductor arrangement 6, 6a, in particular with their common connecting web 10, rests. The resonator inner conductor arrangement 6, 6a preferably only comes into contact with the pedestal arrangements 11. The resonator inner conductor arrangement 6, 6a is preferably not _{arranged or clamped between side walls 3a 1} , 3a ₂ , 3a ₃ , 3a ₄ , 3b ₁ , 3b ₂ , 3b ₃ , 3b _{4 of} the trough-shaped housing elements 2a, 2b. The resonator inner conductor arrangement 6, 6a is preferably arranged exclusively within the receiving space 5 and at a distance from the side walls 3a ₁ , 3a ₂ , 3a ₃ , 3a ₄ , 3b ₁ , 3b ₂ , 3b ₃ , 3b _{4 of} the trough-shaped housing elements 2a, 2b.

The pedestal arrangement 11 is at least partially penetrated by a fastening opening 28 and preferably has a thread. A screw 26 with a screw body 26a and a screw head 26b engages in the two pedestal arrangements 11. By tightening the screw connection Both pedestal arrangements 11, that is to say both trough-shaped housing elements 2a, 2b, are pressed towards one another. Only that pedestal arrangement 11 of the two pedestal arrangements 11 is designed with a thread, which is further spaced from the screw head 26b. The screw body 26a also penetrates the resonator inner conductor arrangement 6, 6a. This is preferably designed exclusively thread-free. In the example shown, the opening 27 in the resonator inner conductor arrangement 6, 6a is larger than the diameter of the screw body 26a.

The screw head 26b is arranged outside the housing 2. In the exemplary embodiment shown, the housing 2 comprises, in particular, the further trough-shaped housing element 2b, an indentation in which the screw head 26b is arranged so that it does not protrude beyond the remaining end wall 4b of the housing element 2b. The screw head 26b is therefore countersunk in a receiving space accessible from the outside in one of the two housing elements 2a, 2b.

The openings, in particular the fastening openings 28, completely penetrate both pedestal arrangements 11 in the exemplary embodiment. The pedestal arrangements 11 are preferably designed in one piece on the respective end walls 4a, 4b and spaced apart from the side walls 3a ₁ , 3a ₂ , 3a ₃ , 3a ₄ , 3b ₁ , 3b ₂ , 3b ₃ , 3b _{4 of} the trough-shaped housing elements 2a, 2b . The pedestal arrangements 11 preferably touch (contact) the resonator inner conductor arrangement 6, 6a directly without a dielectric being arranged in between.

In Figure 8B a cross section through a housing 2 is shown, which consists of a trough-shaped housing element 2a and a cover arrangement 2c. The resonator inner conductor arrangement 6, 6a in turn rests on a pedestal arrangement 11. The pedestal arrangement 11 extends from the end face 4a of the trough-shaped housing element 2a into the receiving space 5. The pedestal arrangement 11 is in turn penetrated completely by a fastening opening 28 which has a thread.

A spacer 30 is also arranged between the resonator inner conductor arrangement 6, 6a and the housing cover 2c. The at least one resonator inner conductor arrangement 6, 6a is therefore between the pedestal arrangement 11 and the at least one spacer 30 clamped. The spacer 30 can consist of a dielectric material or of an electrically conductive material. The fastening opening 28, into which the screw connection 26 at least partially engages, continues through the resonator inner conductor arrangement 6, 6a and the at least one spacer 30 and the cover arrangement 2c. The screw body enters from outside the housing 2 through the fastening opening 28 in the cover arrangement 2c and penetrates the spacer 30 and the resonator inner conductor arrangement 6, 6a completely and the pedestal arrangement 11 at least partially. The screw head 26b is arranged outside the housing 2 on an outside of the cover arrangement 2c.

Figure 8C shows a similar embodiment to that of FIG Figure 8A . In this case, both platform arrangements 11 comprise a receiving space that is at least partially accessible from the outside. The screw head 26b is arranged in the one receiving space. In the other receiving space, a nut 26c is arranged, which is in engagement with the screw body 26a. In this exemplary embodiment, the fastening openings 28 are designed without threads.

Figure 8D corresponds to the embodiment from Figure 8A . The screw connection 26 penetrates a side wall 3a ₁ to 3a ₄ or 3b ₁ to 3b ₄ of a trough-shaped housing element 2a, 2b. Depending on the point of view, it can also be said that the pedestal arrangement 11 is located in each trough-shaped housing element 2a, 2b both on the respective end face 4a, 4b and on the respective side wall 3a ₁ to 3a ₄ or 3b ₁ to 3b ₄ .

The cross section through the coaxial filter 1 according to the invention according to FIG Figure 8E shows that the resonator inner conductor arrangement 6, 6a is soldered to the housing 2, in particular to both trough-shaped housing elements 2a, 2b and there in particular to the respective pedestal arrangements 11 running towards one another. The structure corresponds roughly to that of Figure 8A , whereby a screw connection 26 has been dispensed with. The platform arrangements 11 run from the end walls 4a, 4b into the receiving space 5. The podium arrangements 11 are in turn penetrated by the fastening opening 28. This fastening opening 28 also penetrates the Resonator inner conductor arrangement 6, 6a. The pedestal arrangements 11 each include an end face, the two end faces of the pedestal arrangements 11 facing one another. The resonator inner conductor arrangement 6, 6a lies on these end faces or is clamped between these end faces. A soldered connection 35 is formed on the inner wall formed by the fastening opening 28 in the resonator inner conductor arrangement 6, 6a and on the respective end faces of the pedestal arrangements 11. This solder deposit 35 is accessible via the fastening openings 28 in the pedestal arrangements 11.

Figure 8F shows a similar embodiment as Figure 8E . In this case, the resonator inner conductor arrangement 6, 6a is not penetrated by the fastening opening 28. A soldered connection 35 takes place between the top and bottom of the resonator inner conductor arrangement 6, 6a, in particular the common connecting web 10 and the respective pedestal arrangements 11 of the two trough-shaped housing elements 2a, 2b. The soldered connections 35 are not accessible via the fastening opening 28, but only via the corresponding receiving space 5. The soldered connections 35 can be produced, for example, from a pre-inserted solder preform. This applies to all soldered connections 35. The soldered connections 35 can be melted, for example, by inductive soldering or by heating in a reflow oven. These soldered connections 35 rest in a stepped shoulder in the respective pedestal arrangements 11.

Figure 8G shows a further exemplary embodiment of the coaxial filter 1. The resonator inner conductor arrangement 6, 6a rests on a pedestal arrangement 11 which extends from an end wall 4a, 4b into the receiving space 5. The pedestal arrangement 11 has a projection 36 which passes through an opening in the resonator inner conductor arrangement 6, 6a and is surrounded by support shoulders on which, in addition to a solder deposit 35, part of the resonator inner conductor arrangement 6, 6a, in particular a part of the common connecting web 10 is arranged.

Figure 8H shows a similar embodiment as Figure 8G . The pedestal arrangement 11 is, however, formed both on the end wall 4a and on one or more of the side walls 3a ₁ to 3a ₄ and extends into the receiving space 5. Instead of a second trough-shaped housing element 2b, a cover arrangement 2c is provided. The resonator inner conductor arrangement 6, 6a rests on the pedestal arrangement 11. The same also applies to a solder deposit 35, via which the resonator inner conductor arrangement 6, 6a can be soldered to the pedestal arrangement 11.

As with regard to the exemplary embodiments to the Figures 3A to 3D has been described, the pedestal arrangement 11 is a plurality of non-interconnected individual pedestals or a continuous pedestal.

Figure 8I shows that the resonator inner conductor arrangement 6, 6a _{is soldered to one or more side walls 3a 1} to 3a _{4 of} the trough-shaped housing element 2a. The distance between the resonator inner conductor arrangement 6, 6a and the end wall 4a is approximately the same as the distance between the resonator inner conductor arrangement 6, 6a and the cover arrangement 2c. The wording “approximately” is to be understood to the effect that a difference between the two distances is preferably less than 10%, more preferably less than 5%.

Figure 8J describes a further exemplary embodiment of how the resonator inner conductor arrangement 6, 6a can be soldered to the housing 2. The resonator inner conductor arrangement 6, 6a has a segment 38, which is bent towards the end face 4a of the at least one trough-shaped housing element 2a and soldered to it, at least with respect to the predominant part of the resonator inner conductor 7a to 7n. This segment 38 is preferably the common connecting web 10.

With regard Figure 8K this segment 38 does not run in the direction of the end face 4a, but in the direction of the cover arrangement 2c. The cover arrangement 2c preferably has an opening, as a result of which part of the resonator inner conductor arrangement 6, 6a protrudes therefrom and is soldered to the cover arrangement 2c outside the housing 2.

Figure 8L shows a similar embodiment as Figure 8H . Instead of the resonator inner conductor arrangement 6, 6a being soldered to the pedestal arrangement 11, this is screwed to the pedestal arrangement 11. The screw head 26b is located in the receiving space 5. Part of the resonator inner conductor arrangement 6, 6a rests on the pedestal arrangement 11 and, together with the pedestal arrangement 11, is penetrated by the fastening opening 28. In this case, the fastening opening 28 comprises a thread so that the screw body 26a can be screwed to it. The resonator inner conductor arrangement 6, 6a again comprises a segment 38 which is bent in the direction of the end wall 4a with respect to the individual resonator inner conductors 7a to 7n. The part of the resonator inner conductor arrangement 6, 6a which rests on the pedestal arrangement 11 therefore runs parallel or with one component predominantly parallel to the individual resonator inner conductors 7a to 7n, but is arranged closer to the end wall 4a than the individual resonator inner conductors 7a to 7n. This part is preferably the common connecting web 10. However, it can also be the second end 9 of the individual resonator inner conductors 7a to 7n.

The screw 26 can be an electrically conductive screw or a screw 26 made of a dielectric material.

Figure 8M explains how the coupling between the resonator inner conductor arrangement 6, 6a and the housing 2 can be reinforced. In particular, a dielectric material 39, which is preferably U-shaped in cross-section and thus the second end 9 of the at least one resonator inner conductor, is applied to the second end 9 of at least one or all of the resonator inner conductors 7a to 7n 7a to 7n covered on both sides. A fastening mechanism, in particular in the form of a latching connection, would also be conceivable. The second end 9 could also be completely enclosed with a dielectric material.

In contrast, explained Figure 8N that a pedestal arrangement 11 extends in the direction of the resonator inner conductor arrangement 6, 6a, in particular in the direction of the second end 9 of at least one or all of the resonator inner conductors 7a to 7n, but ends with the formation of a space therefrom.

The executions of the Figures 8M and 8N serve to influence the resonance frequencies. The greater capacitive loading at the open end 9 of the at least one resonator inner conductor 7a to 7n reduces the resonance frequency. Otherwise, a longer resonator inner conductor 7a to 7n would be necessary, which in turn would result in a larger design of the housing 2.

Figure 8O shows a cross section through the coaxial filter 1, as shown in the exploded view Figure 6 is shown. A trough-shaped housing element 2a is closed with the cover arrangement 2c. A platform arrangement 11 protrudes into the receiving space 5 thus formed. The pedestal arrangement 11 is partially penetrated by the fastening opening 28, which comprises a thread. By means of a screw, the resonator inner conductor arrangement 6, 6a, which rests on the pedestal arrangement 11, is firmly screwed to the latter and thereby clamped. The end wall 4a in turn serves to close off a further trough-shaped housing element 2b. In this, too, there is a pedestal arrangement 11 which is only partially penetrated by the fastening opening 28 and which contains a thread. The screw 26 also serves to screw the further resonator inner conductor arrangement 6, 6b to the pedestal arrangement 11.

In Figure 8P a coupling opening 15 is shown, which is made in the end wall 4a of the trough-shaped housing element 2a and allows coupling between the resonator inner conductor arrangement 6, 6a to the further resonator inner conductor arrangement 6, 6b.

A plurality of coupling openings 15 can also be used, which can have any dimensions and shapes (e.g. square, rectangular, slot-shaped, round, oval).

the Figures 8Q , 8R and 8S explain the use of at least two resonator inner conductor arrangements 6, 6a, 6b in a common receiving space 5 using two trough-shaped housing elements 2a, 2b, the end walls 4a, 4b of which together with the respective side walls 3a ₁ to 3a ₄ and 3b ₁ to 3b _{4 form} the housing 2 of the coaxial filter 1. In the thereby delimited common receiving space 5 are in accordance with Figure 8Q two separate resonator inner conductor arrangements 6, 6a, 6b arranged. In this case, two platform arrangements 11 are formed which protrude from the respective end walls 4a, 4b into the receiving space 5. These pedestal arrangements 11 are only partially from the fastening opening 28 and have a thread, the resonator inner conductor arrangements 6, 6a, 6b being screwed and / or clamped to the respective pedestal arrangement 11 via a screw. Soldering would also be possible, with the two trough-shaped housing elements 2a, 2b themselves still being connected to one another via a screw or soldered connection (not shown).

In Figure 8R there is a one-piece resonator inner conductor arrangement 6, 6a, 6b. In the Figure 8Q The separate resonator inner conductor arrangements 6, 6a, 6b shown are additionally connected to one another via a curved connecting section 40 and are formed in one piece. The resonator inner conductor arrangements 6, 6a, 6b are soldered (in particular without a thread) to the pedestal arrangement 11, which has an outwardly continuous fastening opening 28. The resonator inner conductor arrangement 6, 6a, 6b with a U-shaped cross-section can be resilient, so that the individual resonator inner conductors 7a to 7n of the individual resonator inner conductor arrangements 6, 6a, 6b want to move away from one another, whereby the resonator inner conductor arrangement 6, 6a, 6b rests well on the pedestal arrangements 11.

Figure 8S FIG. 13 shows a further embodiment which is similar to that of FIG Figure 8Q Has. At least one, preferably the two platform arrangements 11 that converge are completely penetrated by the fastening opening 28. Between the two separate resonator inner conductor arrangements 6, 6a, 6b there is a spacer 30 which supports the two resonator inner conductor arrangements 6, 6a, 6b from one another. A screw connection penetrates at least one pedestal arrangement 11 and the spacer 30, as well as the two resonator inner conductor arrangements 6, 6a, 6b completely and preferably ends in the further pedestal arrangement 11 the respective pedestal arrangement 11 are screwed or clamped.

A separating element can also be used between the two resonator inner conductor arrangements 6, 6a, 6b in order to reduce the coupling. It is also possible to screw tuning elements in the form of tuning screws from outside the housing 2 to different distances into the receiving space 5 in order to be able to tune the coaxial filter 1.

In principle, partitions can also be used, which are preferably galvanically connected to the housing 2. Such a partition is pushed between the space between two adjacent resonator inner conductors 7a to 7n in order to at least partially reduce the direct coupling. They can also be formed only on the side walls 3a ₁ to 3a ₄ or 3b ₁ to 3b ₄ and / or on the end walls 4a, 4b in order to reduce the volume slightly. It is still the case that two adjacent resonator inner conductors 7a to 7n are in visual contact with one another over their entire length or over their predominant length.

The coaxial filter 1 according to the invention can have any dimensions that differ depending on the frequency range used. The application frequency ranges for such a coaxial filter 1 are typically between 500 MHz and 4500 MHz. A use above or below is also conceivable.

The housing 2 of the coaxial filter 1 can have side lengths which are greater than 20mm, 50mm, 75mm, 100mm, 150mm, 200mm, 250 or 300 mm and which are preferably smaller than 400mm, 375mm, 325mm, 275mm, 225mm, 175mm, 125mm, 90mm, 70mm or 40mm. These side lengths apply in particular in the X or Y direction, that is to say along the respective side walls 3a ₁ , 3a ₂ , 3a ₃ , 3a ₄ or 3b ₁ , 3b ₂ , 3b ₃ , 3b ₄ .

The housing 2 of the coaxial filter 1 can have a thickness which is preferably greater than 3mm, 5mm, 7mm, 9mm, 11mm, 13mm or 15mm and which is more preferably less than 30mm, 25mm, 20mm, 17mm, 13mm, 12mm, 10mm, 6mm or 4mm. Mostly it is between 7mm and 10mm. The wall thickness of metal sheets (eg the resonator inner conductor 7a, ..., 7n) and / or of the housing elements 2a, 2b and / or of the cover arrangement 2c and / or of the end walls 4a, 4b is preferably greater than 0.5mm , 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm and more preferably smaller than 7mm, 6mm, 4.8mm, 3.8mm, 2.8mm, 1.8mm or 0.8mm. Mostly it is in a range between 1mm and 2mm.

The invention is not restricted to the exemplary embodiments described. The scope of protection is defined by the appended claims.

Claims (15)

1. Coaxial filter (1) having the following features:

   - a housing (2) that delimits a common receiving space (5) ;

   - the housing (2) consists of an electrically conducting material and comprises a trough-shaped housing element (2a) that has sidewalls (3a₁, 3a₂, 3a₃, 3a₄) and a front wall (4a), wherein between the sidewalls (3a₁, 3a₂, 3a₃, 3a₄), a space (5a) is closed off by the front wall (4a) on one of their sides, and wherein the sidewalls (3a₁, 3a₂, 3a₃, 3a₄) are integral with the front wall (4a);

   - the housing (2) further comprises:

   a) a further trough-shaped housing element (2b) that comprises sidewalls (3b₁, 3b₂, 3b₃, 3b₄) and a front wall (4b), wherein a further space (5b) between the sidewalls (3b₁, 3b₂, 3b₃, 3b₄) is closed off on one of their sides by the front wall (4b), wherein the sidewalls (3b₁, 3b₂, 3b₃, 3b₄) are integral with the front wall (4b), and wherein the two trough-shaped housing elements (2a, 2b) are placed on top of one another, and so the sidewalls (3a₁, 3a₂, 3a₃, 3a₄, 3b₁, 3b₂, 3b₃, 3b₄) of both trough-shaped housing elements (2a, 2b) run between the two front walls (4a, 4b) and surround the receiving space (5) which is formed by the two spaces (5a, 5b); or

   b) a lid arrangement (2c), wherein the sidewalls (3a₁, 3a₂, 3a₃, 3a₄) run between the front wall (4a) and the lid arrangement (2c) and surround the receiving space (5) which is formed by the space (5a);

   - in addition, at least one resonator inner conductor arrangement (6, 6a) with a one-piece design is provided which is arranged in the receiving space (5), and which preferably consists of or comprises a punched and/or lasered metal sheet;

   - the at least one resonator inner conductor arrangement (6, 6a) comprises a plurality of resonator inner conductors (7a, ..., 7n) which lie in the same plane and have a first end (8) and a second end (9) spaced apart from the first end (8);

   - the at least one resonator inner conductor arrangement (6, 6a) comprises a connecting bridge (10), on which the resonator inner conductors (7a, ..., 7n) are connected to with their first end (8) in an electrically conducting manner;

   - at least two adjacent resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a), which extend in the same direction away from the connecting bridge (10), are in the line of sight of one another over their entire length or over their predominant length;

   - at least one pedestal arrangement (11), wherein the at least one pedestal arrangement (11) extends in direction of the at least one resonator inner conductor arrangement (6, 6a) and ends at a distance therefrom;

   - the at least one pedestal arrangement (11) is integrally:

   a) formed on the front wall (4a, 4b) of a trough-shaped housing element (2a, 2b) if the housing (2) comprises another trough-shaped housing element (2b); or

   b) formed on the lid arrangement (2c) if the housing (2) comprises a lid arrangement (2c); and

   - the sidewalls (3a₁, 3a₂, 3a₃, 3a₄, 3b₁, 3b₂, 3b₃, 3b₄) and the front wall (4a, 4b) of the housing element (2a, 2b) consist of a casting and/or extrusion and/or milling part or comprise a casting and/or extrusion and/or milling part;

   - the resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a) extend on both sides away from the connecting bridge (10);

   - the connecting bridge (10) is divided into different connecting bridge sections (10a, ..., 10n), wherein the connecting bridge sections (10a, ..., 10n) run offset to one another;

   - the resonator inner conductor arrangement (6, 6a) is screwed and/or clamped to the housing (2).
2. Coaxial filter (1) according to claim 1, with the following features:

   - the at least one pedestal arrangement (11) comprises a plurality of individual pedestals spaced apart from one another or a continuous pedestal that extends over at least 50% along the length of a sidewall (3a₁, 3a₂, 3a₃, 3a₄, 3b₁, 3b₂, 3b₃, 3b₄) ;

   - the at least one pedestal arrangement (11) consists of or comprises an electrically conducting material.
3. Coaxial filter (1) according to one of the previous claims, with the following feature:

   - the at least one resonator inner conductor arrangement (6, 6a) is galvanically separated from the housing (2).
4. Coaxial filter (1) according to claim 1 or 2, with the following features:

   - the at least one resonator inner conductor arrangement (6, 6a) is soldered to a side wall (3a₁, 3a₂, 3a₃, 3a₄, 3b₁, 3b₂, 3b₃, 3b₄) of a trough-shaped housing element (2a, 2b) if the housing (2) comprises a further trough-shaped housing element (2b); or

   - the at least one resonator inner conductor arrangement (6, 6a) comprises a segment (38) which is curved at least with regard to the predominant part of the resonator inner conductors (7a, ... , 7n) in the direction of the front side (4a, 4b) of a trough-shaped housing element (2a, 2b) and is soldered thereto if the housing (2) comprises a further trough-shaped housing element (2b), or which is curved at least with regard to the predominant part of the resonator inner conductors (7a, ..., 7n) in the direction of the lid arrangement (2c) and is soldered thereto if the housing (2) comprises a lid arrangement (2c).
5. Coaxial filter (1) according to one of the previous claims, with the following feature:

   - the housing (2) has a thickness which is larger than 3mm, 5mm, 7mm, 9mm, 11mm, 13mm or 15mm and which is smaller than 30mm, 25mm, 20mm, 17mm, 13mm, 12mm, 10mm, 6mm or 4mm.
6. Coaxial filter (1) according to one of the previous claims, with the following feature:

   - at least two or all resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a) are of the same or different length.
7. Coaxial filter (1) according to one of the previous claims, with the following feature:

   - at least two resonator inner conductors (7a, ..., 7n) or all resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a) have over a first partial length (13a) beginning at the first end (8), a smaller width than over a second partial length (13b), which ends at the second end (9), wherein the first partial length (13a) for at least two resonator inner conductors (7a, ..., 7n) preferably has a different length, resulting in a band-stop characteristic.
8. Coaxial filter (1) according to one of the previous claims, with the following features:

   - at least one capacitive or inductive overcoupling between two resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a) that are not adjacent, wherein

   a) the inductive overcoupling is formed by an overcoupling rod that is galvanically connected to the two resonator inner conductors (7a, ..., 7n) and runs between them and a front wall (4a, 4b) of a trough-shaped housing element (2a, 2b) if the housing (2) comprises a further trough-shaped housing element (2b), or the lid arrangement (2a) if the housing (2) comprises a lid arrangement (2c); or

   b) the capacitive overcoupling is formed by an overcoupling element (14), having at least two galvanically connected capacitive coupling surfaces (14a, 14b), wherein each of said capacitive coupling surfaces (14a, 14b) is arranged spaced apart between one of the two resonator inner conductors (7a, ..., 7n) and a front wall (4a, 4b) of a trough-shaped housing element (2a, 2b) if the housing (2) comprises a further trough-shaped housing element (2b), or the lid arrangement (2a) if the housing (2) comprises a lid arrangement (2c), wherein the overcoupling element (14) is galvanically separated from the resonator inner conductors (7a, ..., 7n) and the housing (2).
9. Coaxial filter (1) according to one of the previous claims, with the following features:

   - one electrically conducting separator (20) each begins on each sidewall (3a₁, 3a₂, 3a₃, 3a₄, 3b₁, 3b₂, 3b₃, 3b₄) of both trough-shaped housing elements (2a, 2b) placed on top of one another if the housing (2) comprises a further trough-shaped housing element (2b), or an electrically conducting separator (20) begins on a sidewall (3a₁, 3a₂, 3a₃, 3a₄) of the one trough-shaped housing element (2a) if the housing (2) comprises a lid arrangement (2c) and is connected to these or this sidewall (3a₁, 3a₂, 3a₃, 3a₄, 3b₁, 3b₂, 3b₃, 3b₄) galvanically conductingly and protrudes into the receiving space (5) and runs in the direction of a second sidewall (3a₁, 3a₂, 3a₃, 3a₄, 3b₁, 3b₂, 3b₃, 3b₄) which is opposite of the first sidewall (3a₁, 3a₂, 3a₃, 3a₄, 3b₁, 3b₂, 3b₃, 3b₄) and ends there by forming an opening (21) with it, thus dividing the receiving space (5) at least into a first receiving chamber (5₁) and into a second receiving chamber (5₂) and the opening (21) which connects the at least two receiving chambers (5₁, 5₂);

   - a plurality of resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a) are arranged in the first and the second receiving chamber (5₁, 5₂) of the receiving space (3).
10. Coaxial filter (1) according to claim 9, with the following features:

    - the connecting bridge (10) is:

    a) arranged between the two separators (20) if the housing (2) comprises a further trough-shaped housing element (2b); or

    b) arranged between the separator (20) and the lid arrangement (2c) if the housing (2) comprises a lid arrangement (2c), wherein the first end (8) of the corresponding resonator inner conductors (7a, ..., 7n) has a segment that is curved in the direction of the front wall (4a), so that the resonator inner conductors (7a, ..., 7n) run over the predominant part of their length spaced apart at a predefined distance from the lid arrangement (2c).
11. Coaxial filter (1) according to one of the previous claims, with the following features:

    - a further resonator inner conductor arrangement (6, 6b), wherein:

    a) if the housing (2) comprises a further trough-shaped housing element (2b), the at least one resonator inner conductor arrangement (6, 6a) is fastened to the front wall (4a) of the trough-shaped housing element (2a), and the further resonator inner conductor arrangement (6, 6b) is fastened to the front wall (4b) of the further trough-shaped housing element (2b); or

    b) if the housing (2) comprises a lid arrangement (2c), the coaxial filter comprises an additional trough-shaped housing element (2b), wherein the front wall (4a) of the trough-shaped housing element (2a), which is closed with the lid arrangement (2c), is placed onto the sidewalls (3b1, 3b2, 3b3, 3b4) of the additional trough-shaped housing element (2b), thus forming a further receiving space, wherein the further resonator inner conductor arrangement (6, 6b) is arranged in the further receiving space, and wherein at least one coupling opening (15) is introduced in the front wall (4a) of the trough-shaped housing element (2a), so that a coupling between the individual resonator inner conductor arrangements (6, 6a, 6b) in the different receiving spaces (5) is possible.
12. Coaxial filter (1) according to claim 11, wherein, if the housing (2) comprises a further trough-shaped housing element (2b):

    - between the resonator inner conductor arrangement (6, 6a) and the further resonator inner conductor arrangement (6, 6b), which are arranged in the same receiving space (5), a separating wall is arranged, having at least one coupling opening, through which the individual resonator inner conductor arrangements (6, 6a, 6b) are coupled; or

    - the resonator inner conductor arrangement (6, 6a) and the further resonator inner conductor arrangement (6, 6b), which are arranged in the same receiving space (5), are connected to one another by means of a curved connecting section (40) and designed as one piece.
13. Coaxial filter (1) according to one of the previous claims, with the following feature:

    - at least one first and one second and one third coupling and/or decoupling device (12a, 12b, 12c), which are arranged at different locations of the housing (2) and project into the receiving space (5) from outside the housing (2) and establish a capacitive or inductive or galvanic coupling to different resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a).
14. Coaxial filter (1) according to one of the claims 1 to 13, with the following features:

    - the second end (9) of at least one or all resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a):

    a) runs angled, for example L-shaped; or

    b) double-angled, for example T-shaped or is U-shaped.
15. Coaxial filter (1) according to one of the previous claims, with the following feature:

    - at least one or all of the resonator inner conductors (7a, ..., 7n) of the at least one resonator inner conductor arrangement (6, 6a) extend obliquely or at right angles away from the connecting bridge (10).

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