EP3220473B1 - Coaxial filter in frame construction - Google Patents

Description

The invention relates to coaxial filter in frame construction.

Filters are always used in communications engineering and in high-frequency engineering if only certain frequency components of a signal are to be further processed. In addition to high-pass or low-pass filters, there are also band-pass or band-stop filters. Filters can be realized both digitally and by means of discrete components. The filters can be constructed on a circuit board or be designed as a coaxial filter in the form of milled or cast cavity structures. Filters in coaxial design are usually produced in a die-casting process, the fine-tuning can be done by means of additional rotatable tuning elements.

The JP 3 385 909 B2 describes an RF filter having a housing bottom, two end walls and a housing cover includes, is bounded by a receiving space. In the receiving space resonator inner conductors are arranged, which are galvanically connected to the housing bottom and extending therefrom in the direction of the housing cover. The housing bottom, the housing cover, the end walls and the resonator inner conductor consist of a common part. Side walls close the receiving space on both sides. At the two opposite end faces in each case an input and / or decoupling device is arranged.

In the US 2008/122559 A1 an RF filter is described which comprises two end walls, two side walls and a housing bottom defining a receiving space. A divider extends between the two end walls and divides the receiving space into two areas. The divider is either integrally connected to an end wall and spaced from the other end wall, or is integrally connected to a side wall and spaced from both end walls. Resonator inner conductors are arranged on the divider and extend from this in both areas in the direction of the respective side walls. The divider includes extensions that extend between two resonator inner conductors in a region, thereby dividing each region into at least two resonator chambers. The receiving space can be closed by a lid.

From the US 5 262 742 A is an RF filter known. This comprises two end walls, two side walls, a bottom part and a lid part, which are all screwed together and define a receiving space. A separating web part is screwed to an end wall and extends from this in the direction of the other end wall and ends to form a distance space to this. The separating web part divides the receiving space into two areas. On both side walls resonators are screwed, which extend from the respective side wall in the direction of the Trennstegteils in the respective area. The distance of the resonators to the separating web part is adjustable via a screw connection. An elongated resonator is bolted to both sidewalls and passes through the spacer space.

The JP S58 172001A describes an RF filter that includes a filter housing. In this filter housing, a conductor structure is arranged on a carrier plate spaced from a housing bottom. At different ends of this conductor structure, a coupling to various input and / or output devices takes place. The conductor structure comprises additional L-shaped conductor elements.

The US 8,884,722 B2 describes an RF filter including first and second electromagnetic resonators configured to operate in a TEM mode. A coupling device inductively couples the first and second resonators together.

From the JP 5 341 121 B2 For example, an RF filter is known which comprises a housing bottom and circumferential side walls, through which a receiving space is formed. In the receiving space resonator inner conductors are arranged, which are galvanically connected to the housing bottom and extending away from the latter. The housing bottom, the side walls and the resonator inner conductors are in one piece. A housing cover, which rests on the end faces of the side walls, closes off the receiving space. On two opposite side walls in each case an input and / or output device is arranged.

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

It is therefore the object of the present invention to provide a coaxial filter in frame construction, the ratio of power to volume is improved. This filter should also be as simple and inexpensive to build.

The object is achieved according to independent claim 1. Advantageous developments are advantageously contained in the dependent claims.

The coaxial filter according to the invention in frame construction comprises at least one filter frame, which consists of an electrically conductive medium and identifies a receiving space, wherein the receiving space is disposed within the at least one electrically conductive filter frame. Furthermore, a lid assembly is provided, which is arranged on both opposite sides of the at least one filter frame, so that the receiving space is at least predominantly closed from all sides. Exceptions may arise, for example, in the area of the connection sockets. At least a first Resonator inner conductor is arranged in the receiving space.

It is particularly advantageous that the coaxial filter is constructed in a frame construction, whereby a very low height is achieved. This means that one can see in plan view of the high frequency filter therethrough when the lid assembly is removed. The coaxial filter can be produced in a casting process, in particular in an (aluminum, or zinc) die casting process. Such a coaxial filter can be used in particular for powers of 5 to 20 watts. The power can also be lower or higher. According to the invention, the filter frame is formed integrally with the separating web and the resonator inner conductors. The filter frame could be made of plastic with its resonator inner conductors, which would then have to be provided with an electrically conductive layer.

According to the invention, the coaxial filter also has at least one electrically conductive separating web which rises on a first side of the at least one filter frame and is electrically conductively connected thereto and protrudes into the receiving space and extends in the direction of a second side of the at least one filter frame and there under formation an opening with this ends, whereby the receiving space is divided into at least a first and in at least one second receiving chamber and connecting the two receiving chambers opening. The at least one first resonator inner conductor is arranged in the at least one first receiving chamber of the receiving space. The at least one The first resonator inner conductor is thereby either galvanically connected to a third side of the at least one electrically conductive filter frame or to a first side of the electrically conductive separating web and extends therefrom either in the direction of the separating web or in the direction of the filter frame and ends at a distance in front of the separating web or filter frame. The same applies to a second resonator inner conductor, which is arranged in the second receiving chamber of the receiving space.

The coaxial filter has, in particular, a first input and / or output device and / or at least one second input and / or outcoupling device, which preferably enters the first or second receiving chamber via the first side of the at least one filter frame from the outside, and there predominantly produces capacitive or predominantly inductive coupling to the respective first and second resonator inner conductor. It is also possible for a third input and / or decoupling device to be arranged opposite the first or second input and / or decoupling device, this being preferably arranged on the second side, which lies opposite the first side. This can then produce a predominantly capacitive or predominantly inductive coupling to a first resonator inner conductor and / or a second resonator inner conductor in the first or second exception chamber, wherein the resonator inner conductor in the respective receiving chamber is closest to the third input. and / or decoupling device is arranged. The third input and / or output device preferably passes through the opening.

The input and / or decoupling devices can also be arranged on the third or fourth side.

In one development of the coaxial filter according to the invention, one end of the at least one first resonator inner conductor, which is not galvanically connected to the filter frame or the at least one divider, has an extension section in the direction of the first and / or the second side of the filter frame, whereby the at least a first resonator inner conductor is formed in plan view L-shaped or T-shaped. This extension section preferably runs exclusively parallel to the third or fourth side of the filter frame or parallel to the separating web. He could also run inclined to the third and fourth side of the filter frame. The same applies to the at least one second resonator inner conductor. This may also have such an extension section. As a result, the electrically effective length of the respective resonator inner conductor is increased. At the same time, the capacitive coupling between the resonator inner conductor can be increased via the extension section to the filter frame or the separating web.

The extension sections of all first resonator inner conductors or all second resonator inner conductors can all point in the same direction. They can also be aligned differently.

In order to increase the inductive coupling between two adjacent resonator inner conductors, they can be galvanically connected via a coupling web. This coupling bridge On the one hand, it can be arranged at a distance from the filter frame and, on the other hand, from the separating web. However, it should be arranged at the end of the resonator inner conductor where they are galvanically connected to the filter frame or the divider. The coupling bridge could also be galvanically connected to the filter frame or the separating web on its side facing the filter frame or the separating web.

In a development of the coaxial filter according to the invention, at least one additional capacitive or inductive coupling is provided between two resonator inner conductors which are not adjacent or which do not follow one another in the signal transmission path. Such a coupling is preferably provided in the space between the resonator inner conductors and the lid assembly. An inductive coupling between the two resonator inner conductors is spaced from the other (underlying) resonator inner conductors, as well as from the lid assembly. A capacitive overcoupling is spaced from all resonator inner conductors and from the lid assembly. At the resonator inner conductors to be coupled, the capacitive coupling preferably has a larger area than is the case with the other resonator inner conductors.

In another development of the coaxial filter according to the invention, this comprises a plurality of filter frames, which are arranged one above the other. The cover assembly closes the outer filter frame to the outside and includes at least one intermediate cover. In each case at least one intermediate cover is in each case arranged between two filter frames and separates them from each other.

However, the intermediate cover comprises at least one coupling opening, whereby a coupling takes place between at least two resonator inner conductors of different filter frames. As a result, a cascading can take place or the individual filter paths can be extended.

Figuren 1A bis 15B:

verschiedene Ausführungsbeispiele des erfindungsgemäßen Koaxialfilters in Rahmenbauweise bzw. verschiedene Längsschnitte durch das erfindungsgemäße Koaxialfilter;

Figur 16:

ein Ausführungsbeispiel des erfindungsgemäßen Koaxialfilters, das mehrere Filterrahmen zeigt, die übereinander angeordnet und durch einen Zwischendeckel einer Deckelanordnung voneinander getrennt sind; und

Figuren 17 bis 18B:

weitere Ausführungsbeispiele des erfindungsgemäßen Koaxialfilters in Rahmenbauweise.

Various embodiments of the invention will now be described by way of example with reference to the drawings. Same objects have the same reference numerals. The corresponding figures of the drawings show in detail:

FIGS. 1A to 15B:

various embodiments of the coaxial filter according to the invention in frame construction or different longitudinal sections through the coaxial filter according to the invention;

FIG. 16:

An embodiment of the coaxial filter according to the invention, showing a plurality of filter frame, which are arranged one above the other and separated by an intermediate cover of a lid assembly from each other; and

FIGS. 17 to 18B:

further embodiments of the coaxial filter according to the invention in frame construction.

Figure 1A shows a spatial representation of the coaxial filter 1 according to the invention in frame construction with removed cover assembly. FIG. 1B shows a parallel to the removed lid assembly extending Section in the longitudinal direction through the coaxial filter 1 according to the invention Figure 1A , The main component of the coaxial filter 1 is at least one filter frame 2, which consists of an electrically conductive material and a receiving space 3, wherein the receiving space 3 is disposed within the at least one electrically conductive filter frame 2, whereby the at least one electrically conductive filter frame 2 a border of the receiving space 3 represents. The filter frame 2 is in plan view preferably rectangular or square or at least approximated to this shape.

The lid assembly, not shown, closes the open ends, ie the opposite broad sides of the at least one filter frame 2. In Figure 1A the lid assembly would close the filter frame 2 above and below. The lid assembly may consist of one or more lids. The cover arrangement preferably has at least two outer covers 22, 23. Such a first outer cover 22 and a second outer cover 23 are in FIG. 13 shown. The lid assembly may also include at least one intermediate lid 20, as in FIG FIG. 16 you can see.

The first outer lid 22 rests on the upwardly or forwardly facing side 2a of the filter frame 2. It is galvanically connected to the filter frame 2. The second outer lid 23 rests on the downwardly or rearwardly facing side 2b of the filter frame 2 and is galvanically connected thereto. The two sides 2a and 2b are parallel to each other.

In the Figures 1A and 1B At least one electrically conductive separating web 4 is shown, which rises on a first side 5a of the at least one filter frame 2 and is connected to it in an electrically conductive manner. The at least one divider 4 is formed integrally with the filter frame 2 and protrudes into the receiving space 3. The at least one separating web 4 extends in the direction of a second side 5b opposite the first side 5a and ends there to form an opening 6. As a result, the receiving space 3 is in at least a first receiving chamber 3a and in at least one second receiving chamber 3b and in the two Receiving chambers 3a, 3b connecting opening 6 articulated. At least one first resonator inner conductor 7a is arranged in the at least one first receiving chamber 3a of the receiving space 3. The at least one first resonator inner conductor 7a is within Figure 1A is galvanically connected to a first side 4a of the electrically conductive separating web 4 and extends from this in the direction of a third side 5c of the electrically conductive filter frame 2 and ends at a distance in front of the electrically conductive filter frame 2. It would also be possible that the at least one first resonator Inner conductor 7a has an electrically insulating coating, whereby it is electrically isolated from the electrically conductive filter frame 2. By way of the size of the distance between the at least one first resonator inner conductor 7a and the third side 5c of the filter frame 2, the capacitive coupling from the first resonator inner conductor 7a to the filter frame 2 can be set. However, the distance is smaller, in particular smaller by a multiple, than the first resonator inner conductor 7a long (extension from the divider 4 in the direction of the filter frame 2).

The divider 4 preferably has the same height H as the filter frame 2. This means that both the first outer lid 22, and the second outer lid 23 rest on the filter frame 2 and on the divider 4 and are galvanically connected to both. They preferably lie on the entire first and second side 2a, 2b of the filter frame 2, or on the entire length of the separating web 4. The same applies to the intermediate cover 20, as in FIG. 16 is shown.

In the Figures 14A and 14B It is shown that the divider 4 is U-shaped in plan view and has an outer space 30 which is separated from the receiving space 3 and the first and second receiving chamber 3a, 3b and is accessible from outside the coaxial filter 1. This means that the divider 4 has two longer, spaced side walls, which are interconnected by a shorter side wall. It would also be possible for the at least one separating web 4 to have a gap. In this case, a side peripheral wall of the filter frame 2 would still be closed and rectangular in shape. The divider 4 would therefore be at least partially hollow.

The FIGS. 15A and 15B show an embodiment without the use of the separating web 4. There are also different first resonator inner conductor 7a formed. The at least one first resonator inner conductor 7a is is galvanically connected to one side of the at least one electrically conductive filter frame 2 and extends from this in the direction of another, in particular opposite side of the electrically conductive filter frame 2 and ends at a distance from the opposite side of the electrically conductive filter frame 2 and / or from the opposite Side of the electrically conductive filter frame 2 galvanically isolated. The coaxial filter 1 according to the invention comprises a third input and / or output coupling device 8c, which is arranged on the second side 5b of the at least one filter frame 2 and has a predominantly capacitive or predominantly inductive coupling. In Figure 15A a predominantly inductive coupling takes place to the first resonator inner conductor 7a in the first receiving chamber 3a, which is arranged closest to the second side 5b.

In Figure 1A There are three first resonator inner conductor 7a. However, fewer or considerably more first resonator inner conductors 7a may also be formed.

The coaxial filter 1 from the Figures 1A and 1B also has at least one second resonator inner conductor 7b. The second resonator inner conductor 7b is in Figure 1A galvanically connected to the second side 4b of the electrically conductive separating web 4 and extends from this in the direction of a fourth side 5d of the electrically conductive filter frame 2 and also ends at a distance in front of the electrically conductive filter frame 2 and / or is galvanically separated from this. Here, the same statements apply as they have already been made for the first resonator inner conductor 7a.

The resonator inner conductors 7a, 7b preferably have a smaller height H than the filter frame 2. This means that the cover assembly with its outer covers 22, 23 and possibly its intermediate cover 20 are spaced from the resonator inner conductors 7a, 7b and not on rest it.

The first side 5a of the filter frame 2 is parallel to the second side 5b of the filter frame 2. The third side 5c of the filter frame 2 is parallel to the fourth side 5d of the filter frame 2. The third and fourth sides 5c, 5d of the filter frame 2 are perpendicular to the first one and second side 5a, 5b of the filter frame 2.

With regard FIG. 1B It can be seen that the at least one separating web 4 and the resonator inner conductors 7a, 7b are integrally formed. The same applies to the at least one divider 4 and the filter frame. 2

In this context, on the FIGS. 3A and 3B directed. FIG. 3A also shows a spatial representation of another embodiment of a coaxial filter 1, whereas FIG. 3B a section along the longitudinal axis through the embodiment FIG. 3A shows. In FIG. 3A the at least one first resonator inner conductor 7a is galvanically connected to the third side 5c of the at least one electrically conductive filter frame 2 and extends therefrom in the direction of the first side 4a of the electrically conductive separating web 4 and ends at a distance in front of the electrically conductive separating web 4 and / or is of the electric conductive divider 4 galvanically isolated. The same applies to the second resonator inner conductor 7b. This is galvanically connected to the fourth side 5 d of the at least one electrically conductive filter frame 2 and extends from this in the direction of the second side 4 b of the electrically conductive divider 4 and ends at a distance in front of the divider 4 and / or is galvanically isolated from the divider 4 ,

Preferably, the at least one first resonator inner conductor 7a is arranged in the at least one first receiving chamber 3a of the receiving space 3, whereas the at least one second resonator inner conductor 7b is arranged in the at least one second receiving chamber 3b of the receiving space 3.

It is also true that the resonator inner conductors 7a, 7b, the at least one divider 4 and the corresponding filter frame 2 are integrally formed. A production is preferably carried out by means of a casting process, in particular a die-casting process, such as an aluminum die-casting process. However, it would also be possible for the coaxial filter 1 according to the invention to be produced by means of a milling process.

The coaxial filter 1 off FIG. 2A comprises a first resonator inner conductor 7a, which is galvanically connected to the first side 4a of the electrically conductive separating web 4 and extends therefrom in the direction of the third side 5c of the filter frame 2 and ends at a distance in front of the filter frame 2. In contrast, the second resonator inner conductor 7b is galvanically connected to the fourth side 5d of the filter frame 2 and extends from this in the direction of the second side 4b of the electrically conductive separating web 4 and ends at a distance in front of the electrically conductive separating web 4. It would also be possible for the at least one first resonator inner conductor 7a to be connected to the third side 5c of the filter frame 2, whereas the second resonator inner conductor 7b is connected to the second side 4b of the divider 4. FIG. 2B shows a corresponding longitudinal section through the coaxial filter 1 FIG. 2A , In a sectional plane parallel to the removed lid assembly.

It would also be conceivable for some of the first or second resonator inner conductors 7a, 7b to be connected alternately to the corresponding side of the filter frame 2 or the separating web 4.

The coaxial filter 1 also comprises a first input and / or output coupling device 8a, which is arranged on the first side 5a of the at least one filter frame 2 and produces a predominantly capacitive or predominantly inductive coupling to the first resonator inner conductor 7a, which is closest to the first first side 5a is arranged in the first receiving chamber 3a. In Figure 1A it is an inductive coupling.

The coaxial filter 1 further comprises at least one second input and / or output device 8b, which is arranged on the first side 5a of the at least one filter frame 2 and produces a predominantly capacitive or a predominantly inductive coupling to the second resonator inner conductor 7b which is closest to the first side 5a arranged in the second receiving chamber 3b is. Each input and / or output device 8a, 8b is preferably exclusively coupled to only one resonator inner conductor 7a, 7b.

In FIG. 17 showing a further embodiment of the coaxial filter 1 according to the invention, a third input and / or output device 8c can be seen, which is arranged on the second side 5b of the at least one filter frame 2 and has a predominantly capacitive or predominantly inductive coupling. In FIG. 17 a predominantly inductive coupling takes place to the first resonator inner conductor 7a in the first receiving chamber 3a, which is arranged closest to the second side 5b. At the same time, a predominantly inductive coupling to that resonator inner conductor 7b also takes place, which is arranged closest to the second side 5b in the second receiving chamber 3b. It would also be possible for the third input and / or output coupling device 8c to produce a capacitive or inductive coupling only to a resonator inner conductor 7a, 7b. The third input and / or output device 8c extends through the opening 6 therethrough.

In Figure 1A However, it could also extend eccentrically through the filter frame 2, whereby in this case the two receiving chambers 3a, 3b would be of different sizes.

An off-center course of the at least one separating web 4 is in particular the case if the coaxial filter still has m further separating webs 4 with m ≥ 1, which subdivide the receiving space 3 into m further receiving chambers 3a, 3b, wherein the m further receiving chambers 3a, 3b each have at least one further resonator inner conductor 7a, 7b. In this case, the m further separating webs 4 may alternately be galvanically connected alternately to the first and the second side 5a, 5b of the at least one filter frame 2, whereby the individual receiving chambers 3a, 3b are connected to one another in a meandering manner. This can increase the length of the filter path. The further separating webs 4 can also all be galvanically connected to the first side 5a of the at least one filter frame 2 and protrude into the receiving space 3 and extend in the direction of the second side 5b and terminate there to form an opening 6. In this case, there are a plurality of filter paths, wherein preferably each filter path has its own input and / or outcoupling device 8a, 8b, which is arranged on the first side 5a of the filter frame 2.

The at least one first resonator inner conductor 7a, just like the at least one second resonator inner conductor 7b, is connected at one point only to the filter frame 2 or the separating web 4. This one point is also called the foot point. The at least one first resonator inner conductor 7a is therefore no more than the at least one second resonator inner conductor 7b connected to the lid assembly. This means that the at least one first resonator inner conductor 7a and the at least one second resonator inner conductor 7b have a lower height than the filter frame 2, whereby they are spaced from the lid assembly by a predetermined value. This distance is preferably less than the actual thickness of the resonator inner conductor 7a, 7b. This preferably applies to all resonator inner conductors 7a, 7b.

In Figure 1A the divider 4 is completely spaced from the second side 5b of the filter frame 2. As a result, the opening 6 is formed. In FIG. 12 the at least one divider 4 is at least partially galvanically connected to the second side 5b of the filter frame 2, wherein the divider 4 at the transition to the second side 5b of the filter frame 2 has a lower height than the filter frame 2 towards the lid assembly, not shown, whereby the opening. 6 is formed. The divider 4 here has a bulge or recess through which the opening 6 is formed.

In order to increase the electrically effective length of the resonator inner conductors 7a, 7b, with regard to Figure 1A a second end of the at least one first resonator inner conductor 7a that opposes the first end (this end forms the root) by an extension portion 9a toward the second side 5b of the filter frame 2. As a result, the first resonator inner conductor 7a has the shape of an "L" in plan view. The same applies to the second resonator inner conductor 7b. This also has an extension portion 9 b, which extends in the direction of the second side 5 b of the filter frame 2. It would also be possible for the extension section 9a, 9b of the first or second resonator inner conductor 7a, 7b to extend in the direction of the first side 5a of the filter frame 2. The extension section 9a, 9b could also extend both in the direction of the first side 5a, and in the direction of the second side 5b of the filter frame 2. In this Case would be the respective resonator inner conductor 7a, 7b in plan view T-shaped. As a result, a larger surface is achieved towards the filter frame 2 or with respect to FIG. 3 towards the separating web 4, whereby the capacitive coupling is reinforced.

With regard to Figure 1A The two extension sections 9a, 9b of the two resonator inner conductors 7a, 7b point in the same direction, and in this case in the direction of the second side 5b of the filter frame 2. They could also point both towards the first side 5a of the filter frame 2.

The extension portions 9a, 9b preferably extend at a right angle away from the respective resonator inner conductors 7a, 7b.

The extension sections 9a, 9b are preferably as wide as the respective resonator inner conductor 7a, 7b. They could also be narrower or wider.

The extension sections 9a, 9b are preferably shorter than the respective resonator inner conductor 7a, 7b. They are preferably shorter than the respective resonator inner conductor 7a, 7b by more than half. They could, however, be longer. For example, in the resonator inner conductor 7 a, 7 b, which oppose the opening 6.

The ends of the extension sections 9a, 9b of the resonator inner conductors 7a, 7b, which are arranged closest to the second side 5b of the filter frame, project, for example, over the end of the at least one separating web 4 forth. The two extension sections 9a, 9b of the two resonator inner conductors 7a, 7b are therefore in direct visual contact with each other via the opening 6, whereby a higher coupling is achieved than if they did not protrude beyond the end. The latter case would also be possible, although the coupling would be weaker.

At least one, preferably all extension sections 9a, 9b extend exclusively parallel to the third or fourth side 5c, 5d of the filter frame 2. They could also be inclined relative to the third or fourth side 5c, 5d of the filter frame 2. Both ends of a resonator inner conductor 7a, 7b are preferably the same thickness and more preferably equidistant from the surrounding lids of the lid assembly.

The distance between the individual resonator inner conductors 7a of a receiving chamber 3a with each other is preferably the same size. The same applies to the distance between the second resonator inner conductor 7b with each other in the second receiving chamber 3b. The distances between the individual resonator inner conductors 7a, 7b to each other can also be varied.

In FIG. 4A and in the associated longitudinal section in FIG. 4B, the extension sections 9a of the first resonator inner conductors 7a do not all point in the same direction, ie for example towards the second side 5b of the filter frame 2 FIG. 4A show two extension portions 9a of two adjacent first resonator inner conductor 7a toward each other. The distance between both extension portions 9a is preferably smaller as the distance of the respective resonator inner conductor to the filter frame 2. However, it could also be the same size or larger.

The same applies to the extension sections 9b of the second resonator inner conductor 7b. In the FIGS. 5A and 5B For example, all the extension portions 9a of the first resonator inner conductors 7a point in the same direction, in this case toward the second side 5b of the filter frame 2, whereas all the extension portions 9b of the second resonator inner conductors 7b move in the opposite direction, that is, toward the first side 5a of the filter frame 2 show.

In FIG. 10 For example, an enhanced inductive coupling between two adjacent first resonator inner conductors 7a is shown. For this purpose, a first coupling web 10a is used, which connects the two adjacent resonator inner conductors 7a with each other galvanically. The first coupling web 10a is electrically connected to its at least one divider 4 side facing the at least one divider 4 (are integrally formed). The inductive coupling is strongest when the connection takes place at the root of the respective resonator inner conductor 7a. In FIG. 10 In addition, an inductive coupling between two adjacent second resonator inner conductors 7b is shown. The inserted second coupling web 10 b is spaced from the filter frame 2 and spaced from the at least one separating web 4 is arranged. The inductive coupling via the second coupling web 10b is less than the inductive coupling via the first coupling web 10a because it is further away from the root of the respective resonator inner conductor 7b is. Also, the second coupling rib 10b is integrally formed with the second resonator inner conductors 7b.

The first and second coupling ribs 10a, 10b are attached to the side surfaces of the adjacent first and second resonator inner conductors 7a, 7b, respectively, which are arranged parallel to the first and second sides 5a, 5b of the filter frame 2. The coupling webs 10a, 10b are preferably mounted in the first half of the length of the resonator inner conductors 7a, 7b. The first half begins at the base of the resonator inner conductors 7a, 7b.

In FIG. 11 an inductive coupling between the two resonator inner conductors 7a, 7b is shown, which are arranged closest to the second side 5b of the filter frame 2. The inductive coupling takes place via the opening 6 with a Überkopplungsstab 17. This Überkopplungsstab 17 can be soldered to the two resonator inner conductors 7a, 7b. A one-piece design of the over-coupling rod 17 with the two resonator inner conductors 7a, 7b is also conceivable.

In order to adjust the coupling between two adjacent resonator inner conductors 7a, 7b, separating diaphragms or partitions 11a, 11b are used. FIG. 9 shows that between two adjacent first resonator inner conductors 7a at least a first separation diaphragm 11a (also called first partition wall) is arranged in order to reduce the coupling of the two first resonator inner conductors 7a. The at least one first separating diaphragm 11a is galvanically connected - in this case - with the first side 4a of the at least one separating web 4 and protrudes by a certain length into the first receiving chamber 3a. It would be it is also possible that the first separating diaphragm 11a is galvanically connected to the third side 5c of the filter frame 2 and projects from there into the first receiving chamber 3a. The first divider panel 11a could also be arranged on the lid assembly, not shown.

Also, a second partition 11b (also called a second partition) is formed, which is arranged between two adjacent second resonator inner conductors 7b. For these, the same statements apply as for the first divider 11a.

The dividing diaphragms 11a, 11b are preferably as high as the dividing web 4 and the filter frame 2. In the case of an adjacent cover arrangement, these preferably touch the cover assembly. They are thus preferably galvanically connected at their opposite sides to the respective top cover assembly (e.g., outer cover 22, 23 or intermediate cover 20).

The partitions 11a, 11b may also consist of two parts, wherein both parts of two opposite sides 5c, 4a run towards the center and end to form a gap to each other. The two parts are therefore preferably diametrically opposite. The separating diaphragms 11a, 11b and the separating web 4 or the filter frame 2 are preferably formed in one piece.

In FIG. 8 At least one capacitive overcoupling 15 between two resonator inner conductors 7a in the same receiving chamber 3a is shown. The capacitive overcoupling is formed by an over-coupling element 15, the at least two mechanically and galvanically interconnected capacitive coupling surfaces 15a, 15b, each of these capacitive coupling surfaces 15a, 15b spaced between one of the two resonator inner conductors 7a and the lid assembly is arranged. The over-coupling element 15 is galvanically separated from the resonator inner conductors 7 a, the at least one separating web 4 and the filter frame 2. The over-coupling element 15 is therefore preferably held by a dielectric and is thereby spaced from the aforementioned elements. Via the dielectric, the over-coupling element 15 is electrically isolated on a first resonator inner conductor 7a.

In FIG. 8 the over-coupling element 15 extends exclusively in the first receiving chamber 3a. It would also be possible that this runs exclusively in the second receiving chamber 3b. The capacitive coupling surfaces 15a, 15b of the over-coupling element 15 preferably abut against the extension section 9a of the resonator inner conductor 7a. They should be as far away as possible from the base of the respective first resonator inner conductor 7a above this contact. The capacitive coupling surfaces 15a, 15b are therefore preferably arranged more at the end of the first resonator inner conductor 7a, which is not galvanically connected to the separating web 4 and the filter frame 2, that is the furthest from these. The same would also apply to an over-coupling element 15, which rests in the second receiving chamber 3b.

In FIG. 7C the over-coupling element 15 extends from the first receiving chamber 3 via a further recess 16, which is formed in the at least one divider 4, in the second receiving chamber 3b. This recess 16 is in FIG. 7A to see.

The over-coupling element 15 is preferably arranged in equal parts in the first and in the second receiving chamber 3a, 3b. The coupling surfaces 15a, 15b respectively point in the same direction and preferably in the direction in which the extension sections 9a, 9b are also directed. The over-coupling element 15 is in FIG. 7C galvanically isolated from the divider 4. The recess 16 is completely closed by the dielectric which completely surrounds the over-coupling element 15 over a certain length. In this case, the over-coupling element 15 is a web which has at both ends, which preferably extends to the web course perpendicularly extending coupling surfaces 15a, 15b. These are preferably wider than the bridge. The web itself is preferably completely surrounded by the dielectric along a certain length. A galvanic separation takes place through the dielectric towards the cover arrangement or the separating web 4 or the first or second resonator inner conductor 7a, 7b.

In FIG. 7B the bridge has a shorter length than in FIG. 7C , The web should be so long that the coupling surfaces 15a, 15b come to rest over the extension sections 9a, 9b of the resonator inner conductors 7a, 7b.

In FIG. 6 is again an inductive coupling between two resonator inner conductors 7a shown in the same receiving chamber 3a. In FIG. 11 is one inductive coupling between two resonator inner conductors 7a, 7b in two different receiving chambers 3a, 3b shown. The inductive coupling takes place in FIG. 6 between two resonator inner conductors 7a which are not adjacent or which do not follow one another on the signal transmission path. The inductive overcoupling is formed by the Überkopplungsstab 17 which is galvanically connected to the two resonator inner conductors 7a and extends between these and the lid assembly. The Überkopplungsstab 17 has two ends, which are preferably angled, wherein it is electrically connected at these ends, in particular by a soldering process with the two resonator inner conductors 7a. The Überkopplungsstab 17 is preferably closer to the bottom of the resonator inner conductor 7a with these galvanically connected, as at the free ends. The inductive coupling could also be done without contact. With regard to FIG. 6, the over-coupling rod 17 runs exclusively in the first receiving chamber 3a. However, it could also run exclusively in the second receiving chamber 3b. In FIG. 11 The over-coupling rod 17 extends from the first receiving chamber 3a via the opening 6 into the second receiving chamber 3b. It would also be possible that the Überkopplungsstab 17 via a further recess, as for example in FIG. 7A for the capacitive over-coupling element 15 through which at least one divider 4 passes.

FIG. 16 shows that the coaxial filter 1 comprises a total of n filter frame 2, with n ≥ 2, wherein in each filter frame 2 at least one divider 4 is formed with first and second resonator inner conductors 7a, 7b. The n filter frame 2 are arranged one above the other and preferably completely overlap. They are therefore arranged congruently one above the other. All filter frames 2 preferably have the same dimensions. This applies in particular to the width (page 5c to page 5d) and the length (page 5a to page 5d). Preferably, they can differ only in height from each other.

The lid assembly, not shown, on the one hand completes the outer filter frame 2. The cover assembly also includes at least n-1 intermediate cover 20. At least one of the intermediate cover 20 is disposed between each two filter frame 2. The at least one intermediate cover 20 comprises at least one coupling opening 18, whereby a coupling between at least two resonator inner conductors 7a, 7b different filter frame 2 takes place.

As a result, the filter path can be lengthened in a very simple manner, whereas at the same time the coaxial filter 1 has a compact design. Different filter paths can be connected to each other.

The Figures 18A and 18B show that various tuning elements 19 can be screwed through the lid assembly in the individual receiving chambers 3a, 3b.

For this purpose, the resonator inner conductors 7a, 7b at the end at which they are galvanically separated from the filter frame 2 and the separating web 4, a preferably circular in plan view recess in which the tuning element 19 extends into it. This part-circular recess in plan view can also be found in the filter frame 2, as in Figures 18A and 18B represented, or continue in the divider 4.

The tuning elements 19 can also be arranged next to the extension section 9a or 9b of the respective resonator inner conductors 7a, 7b.

For the coaxial filter 1 in frame construction also apply the following facts.

A surface of the at least one first and / or second resonator inner conductor 7a, 7b, which runs parallel to the cover arrangement, that is to the outer covers 22, 23, is larger than the largest side face of the at least one first and / or second resonator inner conductor 7a 7b, which runs transversely, preferably perpendicular to the cover arrangement, that is to say to the outer covers 22, 23. With regard to Figure 1A For example, the first resonator inner conductor 7a includes five side surfaces and two surfaces. One surface is disposed adjacent to the first outer lid 22 and another surface is disposed adjacent to the second outer lid 23.

A cross section and a longitudinal section through the at least one first and / or second resonator inner conductor 7a, 7b is preferably angular, in particular rectangular or square.

A surface of the at least one first and / or second separating diaphragm 11a, 11b, which runs parallel to the cover arrangement, that is to say to the outer covers 22, 23, is smaller than the largest or smallest lateral surface of the at least one first and / or second partition panel 11a, 11b, which transversely, preferably perpendicular to the cover assembly, so to the outer covers 22, 23 extends. With regard to FIG. 9 For example, the at least one first divider 11a includes three side surfaces and two surfaces. One surface is disposed adjacent to the first outer lid 22 and another surface is disposed adjacent to the second outer lid 23. Preferably, one or both surfaces of the at least one first divider panel 11a are galvanically connected (touching each other) to one or both of the outer panels 22, 23. The same applies preferably also for the at least one second separating diaphragm 11b. In contrast, the surfaces of the resonator inner conductors 7a, 7b are arranged without contact to the outer covers 22, 23, that is spaced therefrom.

Two immediately adjacent first and / or second resonator inner conductors 7a, 7b, which are arranged in the same receiving chamber 3a, 3b, preferably have visual contact with one another. Preferably, a receiving chamber 3a, 3b comprises at least two resonator inner conductors 7a, 7b. Separating devices within the respective receiving chamber 3a, 3b, such as separating diaphragms 11a, 11b, do not extend over the entire width of the respective receiving chamber 3a, 3b. The width is defined, for example, by the at least one divider 4 to the third side 5c or the fourth side 5d of the filter frame 2. This (direct) coupling of two resonator inner conductors 7a, 7b in the same receiving chamber 3a, 3b possible, although this coupling at Using a divider 11a, 11b is weaker than without such.

In the following, some embodiments of the coaxial filter 1 according to the invention in frame construction 1 will be highlighted again separately.

• der Trennsteg 4 einen Zwischen- oder Außenraum 30 aufweist, der von dem Aufnahmeraum 3 bzw. der ersten und zweiten Aufnahmekammer 3a, 3b getrennt, also unzugänglich ist.

An advantage of the coaxial filter 1 is when:

• the separating web 4 has an intermediate or outer space 30, which is separated from the receiving space 3 or the first and second receiving chamber 3a, 3b, that is inaccessible.

• der zumindest eine Trennsteg 4 mittig oder außermittig durch den Filterrahmen 2 verläuft.

An additional advantage of the coaxial filter 1 is when:

• the at least one separating web 4 extends centrally or eccentrically through the filter frame 2.

• eine erste Ein- und/oder Auskoppelvorrichtung 8a ausgebildet ist, die vorzugsweise an der ersten Seite 5a des zumindest einen Filterrahmens 2 angeordnet ist und eine kapazitive oder induktive bzw. überwiegend kapazitive oder überwiegend induktive Kopplung zu dem zumindest einen ersten Resonator-Innenleiter 7a in der ersten Aufnahmekammer herstellt 3a, der am nächsten zu der ersten Seite 5a angeordnet ist; und/oder
• zumindest eine zweite Ein- und/oder Auskoppelvorrichtung 8b ausgebildet ist, die vorzugsweise an der ersten Seite 5a des zumindest einen Filterrahmens 2 angeordnet ist und eine kapazitive oder induktive bzw. überwiegend kapazitive oder überwiegend induktive Kopplung zu dem zumindest einen zweiten Resonator-Innenleiter 7b in der zweiten Aufnahmekammer 3b herstellt, der am nächsten zu der ersten Seite 5a angeordnet ist.

A complementary advantage of the coaxial filter 1 is when:

• a first input and / or output device 8a is formed, which is preferably arranged on the first side 5a of the at least one filter frame 2 and a capacitive or inductive or predominantly capacitive or predominantly inductive coupling to the at least one first resonator inner conductor 7a in the first receiving chamber 3a, which is arranged closest to the first side 5a; and or
• at least one second input and / or decoupling device 8b is formed, which is preferably arranged on the first side 5a of the at least one filter frame 2 and a capacitive or inductive or predominantly capacitive or predominantly inductive coupling to the at least one second resonator inner conductor 7b in the second receiving chamber 3b manufactures which is located closest to the first side 5a.

• eine dritte Ein- und/oder Auskoppelvorrichtung 8c ausgebildet ist, die vorzugsweise an der zweiten Seite 5b des zumindest einen Filterrahmens 2 angeordnet ist und eine kapazitive oder induktive bzw. überwiegend kapazitive oder überwiegend induktive Kopplung zu dem zumindest:
  1. i. einen ersten Resonator-Innenleiter 7a in der ersten Aufnahmekammer 3a herstellt, der am nächsten zu der zweiten Seite 5b angeordnet ist; und/oder
  2. ii. einen zweiten Resonator-Innenleiter 7b in der zweiten Aufnahmekammer 3b herstellt, der am nächsten zu der zweiten Seite 5b angeordnet ist.

Another advantage of the coaxial filter 1 is when:

• a third input and / or output device 8c is formed, which is preferably arranged on the second side 5b of the at least one filter frame 2 and a capacitive or inductive or predominantly capacitive or predominantly inductive coupling to the at least:
  1. i. a first resonator inner conductor 7a is made in the first accommodating chamber 3a, which is located closest to the second side 5b; and or
  2. ii. makes a second resonator inner conductor 7b in the second accommodating chamber 3b, which is located closest to the second side 5b.

• die Verlängerungsabschnitte 9a aller ersten Resonator-Innenleiter 7a in die gleiche Richtung zeigen; und/oder
  die Verlängerungsabschnitte 9b aller zweiten Resonator-Innenleiter 7b in die gleiche Richtung zeigen; und/oder
• der Verlängerungsabschnitt 9a des zumindest einen ersten Resonator-Innenleiters 7a in die gleiche Richtung zeigt wie der Verlängerungsabschnitt 9b des zumindest einen zweiten Resonator-Innenleiters 7b; oder
  der Verlängerungsabschnitt 9a des zumindest einen ersten Resonator-Innenleiters 7a in die entgegengesetzte Richtung zeigt wie der Verlängerungsabschnitt 9b des zumindest einen zweiten Resonator-Innenleiters 7b.

In addition, there is an advantage of the coaxial filter 1 when:

• the extension portions 9a of all first resonator inner conductors 7a point in the same direction; and or
  the extension portions 9b of all second resonator inner conductors 7b point in the same direction; and or
• the extension portion 9a of the at least one first resonator inner conductor 7a faces in the same direction as the extension portion 9b of the at least one second resonator inner conductor 7b; or
  the extension portion 9a of the at least one first resonator inner conductor 7a in the opposite direction as the extension portion 9b of the at least one second resonator inner conductor 7b.

• in jedem Filterrahmen 2 zumindest ein Trennsteg 4 mit ersten und zweiten Resonator-Innenleitern 7a, 7b ausgebildet ist.

In addition, there is an advantage of the coaxial filter 1 when:

• in each filter frame 2, at least one divider 4 is formed with first and second resonator inner conductors 7a, 7b.

The invention is not limited to the described embodiments. In the context of the invention, all described and / or drawn features can be combined with each other as desired.

Claims (14)

1. Coaxial filter (1) having a frame construction, having the following features:

   - at least one filter frame (2), which consists of an electrically conductive medium and has a receiving space (3) having a first receiving chamber (3a), the receiving space (3) being arranged inside the at least one electrically conductive filter frame (2), resulting in the at least one electrically conductive filter frame (2) forming a border of the receiving space (3);

   - a cover arrangement, which is arranged on the two open ends of the at least one filter frame (2), in such a way that the receiving space (3) is closed on all sides;

   - at least one first resonator internal conductor (7a) is arranged in the receiving space (3);

   - at least one electrically conductive separating web (4) originates on a first face (5a) of the at least one filter frame (2) and is galvanically conductively connected thereto, and protrudes into the receiving space (3), and extends in the direction of a second face (5b), opposing the first face (5a), of the at least one filter frame (2) where it ends so as to form an opening (6) therewith, causing the receiving space (3) to be divided at least into the first receiving chamber (3a) and a second receiving chamber (3b) and the opening (6) connecting the at least two receiving chambers (3a, 3b);

   - the at least one first resonator internal conductor (7a) is arranged in the at least one first receiving chamber (3a) of the receiving space (3);

   - the at least one first resonator internal conductor (7a) is:

   a) galvanically connected to a third face (5c) of the at least one electrically conductive filter frame (2), and extends therefrom in the direction of a first face (4a) of the electrically conductive separating web (4), and ends at a distance from the electrically conductive separating web (4); or

   b) galvanically connected to the first face (4a) of the electrically conductive separating web (4), and extends therefrom in the direction of the third face (5c) of the at least one electrically conductive filter frame (2), and ends at a distance from the electrically conductive filter frame (2); and

   - at least one second resonator internal conductor (7b) is arranged in the at least one second receiving chamber (3b) of the receiving space (3)

   - the at least one second resonator internal conductor (7b) is:

   a) galvanically connected to a fourth face (5d) of the at least one electrically conductive filter frame (2), and extends therefrom in the direction of a second face (4b) of the electrically conductive separating web (4), and ends at a distance from the electrically conductive separating web (4); or

   b) galvanically connected to the second face (4b) of the electrically conductive separating web (4), and extends therefrom in the direction of the fourth face (5d) of the at least one electrically conductive filter frame (2), and ends at a distance from the electrically conductive filter frame (2); and

   characterized by, that

   - the at least one filter frame (2) is formed integrally together with the at least one separating web (4) and the at least one first and second resonator internal conductor (7a, 7b).
2. Coaxial filter (1) according to claim 1, characterized by the following feature:

   - the at least one filter frame (2) is produced by casting together with the at least one separating web (4) and the at least one first and second resonator internal conductor (7a, 7b).
3. Coaxial filter (1) according to any of the preceding claims, characterized by the following features:

   - the at least one separating web (4) is galvanically connected to the second face (5b) of the filter frame (2), the separating web (4) having a smaller height than the filter frame (2) towards the cover arrangement at the transition to the second face (5b) of the filter frame (2), resulting in the opening (6) being formed; or

   - the at least one separating web (4) is spaced apart from the second face (5b) of the filter frame (2), resulting in the opening (6) being formed.
4. Coaxial filter (1) according to any of the preceding claims, characterized by the following features:

   - the at least one first resonator internal conductor (7a) has a smaller height than the filter frame (2) and/or than the separating web (4) and is spaced apart from the cover arrangement by a predetermined amount; and/or

   - the at least one second resonator internal conductor (7b) has a smaller height than the filter frame (2) and/or than the separating web (4) and is spaced apart from the cover arrangement by a predetermined amount.
5. Coaxial filter (1) according to any of the preceding claims, characterized by the following features:

   a)

   - the at least one first resonator internal conductor (7a) is galvanically connected, at the first end thereof, to the third face (5c) of the filter frame (2) or to the first face (4a) of the at least one separating web (4);

   - a second end of the at least one first resonator internal conductor (7a), opposing the first end, comprises an extension portion (9a) in the direction of the first and/or second face (5a, 5b) of the filter frame (2), resulting in the at least one first resonator internal conductor (7a) being formed L-shaped or T-shaped in a plan view;

   and/or

   b)

   - the at least one second resonator internal conductor (7b) is galvanically connected, at the first end thereof, to the fourth face (5d) of the filter frame (2) or to the second face (4b) of the at least one separating web (4);

   - a second end of the at least one second resonator internal conductor (7b), opposing the first end, comprises an extension portion (9b) in the direction of the first and/or second face (5a, 5b) of the filter frame (2), resulting in the at least one second resonator internal conductor (7b) being formed L-shaped or T-shaped in a plan view.
6. Coaxial filter (1) according to any of the preceding claims, characterized by the following features:

   - two adjacent first resonator internal conductors (7a) are galvanically interconnected via a first coupling web (10a), the first coupling web (10a):

   a) being arranged spaced apart from the filter frame (2) and spaced apart from the at least one separating web (4); or

   b) being galvanically connected, at the face thereof facing the filter frame (2) or the at least one separating web (4), to the filter frame (2) or rather to the at least one separating web (4); and/or

   - two adjacent second resonator internal conductors (7b) are galvanically interconnected via a second coupling web (10b), the second coupling web (10b):

   a) being arranged spaced apart from the filter frame (2) and spaced apart from the at least one separating web (4); or

   b) being galvanically connected, at the face thereof facing the filter frame (2) or the at least one separating web (4), to the filter frame (2) or rather to the at least one separating web (4).
7. Coaxial filter (1) according to any of the preceding claims, characterized by the following features:

   - at least one first separating screen (11a) is arranged between two adjacent first resonator internal conductors (7a) so as to reduce the coupling between the two first resonator internal conductors (7a), the at least one first separating screen (11a) being galvanically connected to the third face (5c) of the filter frame (2) and/or to the first face (4a) of the at least one separating web (4) and protruding into the first receiving chamber (3a) by a particular length; and/or

   - at least one second separating screen (11b) is arranged between two adjacent second resonator internal conductors (7b) so as to reduce the coupling between the two second resonator internal conductors (7b), the at least one second separating screen (11b) being galvanically connected to the fourth face (5d) of the filter frame (2) and/or to the second face (4b) of the at least one separating web (4) and protruding into the second receiving chamber (3b) by a particular length.
8. Coaxial filter (1) according to any of the preceding claims, characterized by the following feature:

   - at least one capacitive or inductive coupling is provided between two resonator internal conductors (7a, 7b) which are non-adjacent or not consecutive on the signal transmission path.
9. Coaxial filter (1) according to claim 8, characterized by the following feature:

   - the at least one capacitive or inductive coupling is arranged between two resonator internal conductors (7a, 7b) in the same receiving chamber (3a, 3b) or between two resonator internal conductors (7a, 7b) in two different receiving chambers (3a, 3b).
10. Coaxial filter (1) according to either claim 8 or claim 9, characterized by the following features:

    - the inductive coupling is formed by a coupling rod (17), which is galvanically connected to the two resonator internal conductors (7a, 7b) and extends between them and the cover arrangement;

    - the coupling rod (17) extends:

    a) exclusively in the first receiving chamber (3a); or

    b) exclusively in the second receiving chamber (3b); or

    c) from the first receiving chamber (3a), via the opening (6) or via a further recess (16) in the at least one separating web (4), into the second receiving chamber (3b).
11. Coaxial filter (1) according to any of claims 8 to 10, characterized by the following features:

    - the capacitive coupling is formed by a coupling element (15) which comprises at least two interconnected capacitive coupling faces (15a, 15b), each of these capacitive coupling faces (15a, 15b) being arranged spaced apart between one of the two resonator internal conductors (7a, 7b) and the cover arrangement;

    - the coupling element (15) is galvanically separated from the resonator internal conductors (7a, 7b), the at least one separating web (4) and the filter frame (2); and

    - the coupling element (15) extends:

    a) exclusively in the first receiving chamber (3a); or

    b) exclusively in the second receiving chamber (3b); or

    c) from the first receiving chamber (3a), via the opening (6) or via a further recess (16) in the at least one separating web (4), into the second receiving chamber (3b).
12. Coaxial filter (1) according to any of the preceding claims, characterized by the following feature:

    - a surface of the at least one first and/or second resonator internal conductor (7a, 7b), which extends parallel to the cover arrangement, in other words to the outer covers (22, 23), is larger than the largest side face of the respective at least one resonator internal conductor (7a, 7b), which extends transverse, preferably perpendicular, to the cover arrangement, in other words to the outer covers (22, 23).
13. Coaxial filter (1) according to any of the preceding claims, characterized by the following features:

    - the coaxial filter (1) comprises n filter frames (2), where n ≥ 2, a plurality of resonator internal conductors (7a, 7b) being formed in each filter frame (2);

    - the n filter frames (2) are arranged above one another;

    - the cover arrangement closes off the outer filter frame (2);

    - the cover arrangement comprises at least n-1 intermediate covers (20);

    - at least one of the intermediate covers (20) is arranged between every two filter frames (2);

    - the intermediate cover (20) comprises at least one coupling opening (18), resulting in coupling being provided between at least two resonator internal conductors (7a, 7b) of different filter frames (2).
14. Coaxial filter (1) according to any of the preceding claims, characterized by the following features:

    - the coaxial filter (1) also comprises m further separating webs, where m ≥ 1, which subdivide the receiving space (3) into m further receiving chambers, the m further receiving chambers each comprising at least one further resonator internal conductor, and the m further separating webs

    a) being galvanically conductively connected to the at least one filter frame (2) at the first face (5a) thereof, and protruding into the receiving space (3), and extending in the direction of the second face (5b) where it ends so as to form an opening therewith; or

    b) being galvanically conductively connected alternately to the first and second face (5a, 5b) of the at least one filter frame (2), resulting in the individual receiving chambers (3a, 3b) being interconnected in a meander shape.

Images