EP3320578B1 - Threadless tuning elements for coaxial resonators, and method for tuning same - Google Patents

Description

The invention relates to a high-frequency filter in a coaxial design, which can be tuned via at least one tuning element, wherein the tuning element is threadless within the high-frequency filter movable.

In radio systems, especially in the mobile sector, a common antenna is often used for transmit and receive signals. The transmit and receive signals each use different frequency ranges, and the antenna must be suitable for transmitting and receiving in both frequency ranges. For the separation of the transmit and receive signals therefore a suitable frequency filtering is required, with the one hand, the transmission signals from the transmitter to the antenna and on the other hand, the received signals are forwarded from the antenna to the receiver. For splitting the send and receive signals or for merging or separating mobile radio bands Today, inter alia, high-frequency filters are used in coaxial design. Two interconnected high-frequency filters form a so-called duplex switch, which allows a largely decoupled interconnection of transmitters and receivers to a common antenna. For example, a pair of high-frequency filters can be used, both of which allow a certain frequency band (bandpass filter). Alternatively, a pair of high frequency filters may be used, both of which block a particular frequency band (bandstop filter). Further, a pair of high frequency filters may be used, one of which filters below a frequency between transmit and receive bands and blocks frequencies above that frequency (low pass filter), and the other filter locks frequencies below a frequency between transmit and receive bands and above passing frequencies (high pass filter). Other combinations of the just mentioned filter types are conceivable. This also applies to high-frequency filters, which are constructed as a single filter, ie have only one input and one output.

High-frequency filters, which consist of coaxial resonators, can be easily produced from milling or casting parts. In addition, these resonators ensure a high electrical quality and a relatively high temperature stability.

In order to achieve optimal filter results, however, a fine-tuning after production is necessary.

The US 2011/102110 A1 describes a high-frequency filter comprising a housing bottom, a housing cover spaced from the housing cover and a circumferential between the housing bottom and the housing cover housing wall. A resonator inner conductor is galvanically connected to the housing bottom and extends in the direction of the housing cover. The housing cover comprises an insertion opening above the resonator inner conductor. In this a passage, in particular in the form of a sleeve is used, this passage is penetrated by a tuning element. The tuning element extends in the direction of the resonator inner conductor. Between the implementation and the tuning element, a sealing ring is still used.

The US 2011/0115575 A1 describes a high-frequency filter in cavity construction, which comprises a housing bottom, a housing cover spaced from the housing cover and a circumferential housing wall between the housing cover and the housing wall. A first resonator inner conductor is attached to the housing bottom and extends in the direction of the housing cover. In the housing cover, a second resonator inner conductor is formed and extends in the direction of the first resonator inner conductor. A helical tuning element can be screwed into an opening in the second resonator inner conductor, protruding therefrom within the high-frequency filter and extending in the direction of the first resonator inner conductor.

From the DE 10 61 848 B is a tunable line resonant circuit in the form of a concentric double line known. The double lines thus have the form of a Pipe part with the outer shell and a two-part inner conductor, wherein between the two parts a distance space is formed. In parts of the inner conductor are hollow, with a piston-like displaceable part is arranged in these. Between the two parts of the inner conductor and the piston-like displaceable part, an insulating piece is still arranged.

From the WO 2014/063829 A1 For example, a high frequency filter is known in which tuning elements are introduced into the resonator. The introduction of these tuning elements causes a change in the resonant frequency of the high-frequency filter. The tuning elements are screwed in from outside the high-frequency filter. This is done via a threaded connection between the tuning element and a socket which is inserted into an opening of the high-frequency filter.

A disadvantage of the WO 2014/063829 A1 is that the introduction of such a socket is expensive together with the necessary thread and a vote can be difficult to automate.

From the DE 26 20 769 A1 is a tunable high frequency filter known. An inner conductor is galvanically connected to an end face of the high-frequency housing and extends from this end face in the direction of an opposite further end face of the high-frequency housing. At this further end face a pin is arranged, which stretches in the direction of the inner conductor. The inner conductor comprises an inner conductor bore into which the pin protrudes. The inner conductor is formed in two parts, the second part being telescopic is longitudinally movable in the first part, whereby the inner conductor is constructed in several parts and variable in length. The distance by which the second part of the inner conductor relative to the first part of the inner conductor can be moved, can be adjusted by a threaded rod, which is fixedly connected to the second part of the inner conductor and is actuated from the outside of the high-frequency filter.

From the DE 10 2010 056 048 A1 Another high-frequency filter is known. This comprises an inner conductor, which is galvanically connected to a housing bottom of the high-frequency filter and extends from the housing bottom in the direction of the housing cover. At the same time, a first tuning element extends from the housing cover in the direction of the housing bottom. The inner conductor includes an inner conductor bore into which the first tuning element extends. A second tuning element can be screwed or inserted from outside the high-frequency filter in the inner conductor bore via a thread.

A disadvantage of the DE 10 2010 056 048 A1 is that when using a thread can cause abrasion, which leads to intermodulation products. In the event that the second tuning element is merely inserted, the diameter of the inner conductor bore and the outer diameter of the Abstimmelements must be very closely matched, so that a permanent grip is ensured.

The object of the present invention is therefore a high-frequency filter and a method for tuning of the high-frequency filter, which compared to the prior art cheaper and easier to manufacture, and is carried out and delivers better results over a longer period.

The object is achieved with respect to the high-frequency filter by the features of claim 1 and with respect to the method for adjusting the high-frequency filter by the features of claim 14. In the dependent claims 2 to 13 are advantageous embodiments of the high-frequency filter according to the invention and in the dependent claim 15 there is an advantageous embodiment of the method for balancing the high-frequency filter.
The high-frequency filter according to the invention in coaxial design comprises at least one resonator with a first inner conductor and with an outer conductor housing. The outer conductor housing comprises a housing bottom, a housing cover which is at a distance from the housing bottom, and a housing wall which rotates between the housing bottom and the housing cover. A first inner conductor is galvanically connected to the housing bottom and extends in the axial direction from the housing bottom in the direction of the housing cover. The first inner conductor ends at a distance in front of the housing cover and / or is galvanically separated from the housing cover. The resonator further comprises a second inner conductor, which is galvanically connected to the housing cover and extending in the axial direction from the housing cover in the direction of the housing bottom. The first and the second inner conductor are axially non-displaceable, so length variably arranged and coaxial with each other. The first inner conductor and the housing bottom, as well as the second inner conductor and the housing cover, preferably formed in one piece. The first and / or second inner conductor have an inner conductor bore. The inner conductor bore of the first or second inner conductor passes through the outer conductor housing and opens into an insertion opening. A tuning element is arranged axially displaceable within the inner conductor bore of the first or second inner conductor. In this case, the tuning element is designed and / or arranged so that a portion of the Abstimmelements dips to different depths in the free space between the two inner conductors. Furthermore, a bush or a sleeve within the inner conductor bore between the first inner conductor and the tuning element or the second inner conductor and the tuning element is arranged positively or non-positively. Alternatively or additionally, the tuning element has a region with a widened diameter, this region being located either in the center of the tuning element and / or at the end of the tuning element, which is arranged closer to the insertion opening. The region with the widened diameter is elastically deformable, at least in the radial direction, on the longitudinal axis, which extends centrally through the tuning element. After the adjustment of the filter, the tuning element is preferably permanently fixed within the inner conductor bore. This is done by means of an adhesive bond, wherein the adhesive bond is introduced from outside the outer conductor housing via the insertion opening in the inner conductor bore, whereby the end of the Abstimmelements, which is closer to the insertion, is connected to the inner wall of the inner conductor bore.

It is particularly advantageous that the tuning element is axially displaceable, whereby no thread is necessary. Due to the fact that the tuning element is axially displaceable in the inner conductor bore, smaller filters can be produced because the diameter of the inner conductor bore is no longer limited to a minimum diameter which was previously necessary in order to be able to receive a thread. The elimination of the thread also results in less metallic abrasion during tuning, which would cause disturbing effects in the high-frequency filter (PIM - passive intermodulation). The tuning element can for example be pressed in, preferably injected with compressed air into the inner conductor bore. It is furthermore advantageous that, in addition to a first inner conductor, there is also a second inner conductor, wherein both inner conductors extend coaxially toward one another. As a result, improved filter effects can be achieved, wherein the tuning of the high-frequency filter can be particularly easily done by the tuning element is pushed different distances in the resonator. By using a bushing or sleeve, the inner conductor bore does not need to be specially aftertreated to ensure that the tuning element fits snugly. In addition, the inner conductor bore can be made with a uniform diameter. Later, then by choosing the appropriate socket or sleeve, the diameter of the tuning element can be chosen arbitrarily. Characterized in that the tuning element has an elastic region with a widened diameter, it can be ensured even without the use of a thread that the tuning element sits securely and permanently within the inner conductor bore.

The threadless shifting is not known in this context. True, in the US 4,460,878 shown a threadless displacement of various components, but this is not a tuning element, but an extension of the inner conductor. The use of multiple inner conductors, as well as their non-displaceable attachment to a housing cover and on a housing bottom is shown just as little as that the inner conductor bore of the first or second inner conductor opens into an insertion opening on the outer conductor housing and thus is directly accessible from the outside. Furthermore, no use of a socket or sleeve is taught. Nor is it shown that the tuning element should have a widened region that is elastic.

The inventive method for tuning the high-frequency filter, as has been described for example according to the independent claim 1, comprises various process steps. In a first method step, the high frequency filter is closed. In the further method step, a connection is made between a fastening device which is arranged on the tuning element, with a coupling device of the adjusting device. In a next method step, the tuning element is inserted into the inner conductor bore of the first or second inner conductor. These steps can be performed in any order. In addition, the filter properties are measured, wherein, depending on the measurement result, the tuning element continues in the direction of the insertion opening or away from the insertion opening by means of the coupling device the adjustment is moved. Subsequently, the steps "measuring" and "shifting" are repeated until the high-frequency filter has the desired filter characteristics. When this condition is reached, an adhesive bond is added between the tuning element and the inner conductor bore of the first or second inner conductor, whereby the tuning element is permanently fixed immovably in its axial position within the inner conductor bore.

Particularly advantageous here is the axial displacement of the tuning element within the inner conductor bore, which can be done particularly easily via the coupling device, which is part of the adjusting device, by means of a linear motor or stepper motor.

The widening of a portion of the tuning member also means that this enlarged diameter portion has an excess in the inner conductor bore and the remaining portion is undersized with respect to the inner conductor bore. The area with the broadened diameter causes the area without the broadened diameter centered within the inner conductor bore is arranged. The tuning element is frictionally engaged within the inner conductor bore, but can still be moved axially by means of a stepping motor or a linear motor. An independent displacement of the Abstimmelements no longer takes place, so that this example, very easily by means of an adhesive bond permanently on the inner conductor bore, ie on the inner wall of the inner conductor bore, can be fixed.

In order to facilitate the elastic deformability, the region with the enlarged diameter can be made at least partially slotted. Thereby, the tuning element can be easily inserted into the inner conductor bore, while still ensuring that the tuning element frictionally rests within the inner conductor bore and not due to gravity alone, or vibrations within the manufacturing or adjustment of the high-frequency filter in changed his position.

The tuning element is disposed in the inner conductor bore of the first inner conductor and protrudes out of this into the inner conductor bore of the second inner conductor, wherein both inner conductors preferably do not touch on their front side and further preferably are arranged without overlapping each other, so that neither of the two Inner conductor immersed in the other inner conductor. It would also be possible if the tuning element is arranged in the inner conductor bore of the second inner conductor and projects out of this into the inner conductor bore of the first inner conductor. Again, both inner conductors should not touch and can also be arranged without overlap each other. An overlap would also be possible. In another embodiment, the inner conductor bore of the first inner conductor has a larger diameter than the second inner conductor as a whole, wherein the second inner conductor then at least partially immersed in the inner conductor bore of the first inner conductor. Between both inner conductors, which in this case overlap at least partially radially outward, a distance space is formed, ie the inner conductors do not touch. In this case, the tuning element is designed and / or arranged such that at least a portion of the tuning element dips differently far into the free space between the two inner conductors. The tuning element may be mushroom-shaped in this case, for example. The same applies to the case that the inner conductor bore of the second inner conductor has a larger diameter than the first inner conductor and this then dips into the inner conductor bore of the second inner conductor.

In a further embodiment, it may also be possible for the tuning element to have a receiving opening at the end that is furthest from the insertion opening. In this case, when the tuning element is disposed in the inner conductor bore of the first inner conductor, the second inner conductor may be immersed in the receiving opening of the tuning element. The same applies even if the tuning element is arranged in the inner conductor bore of the second inner conductor, in which case the first inner conductor is immersed in this.

The corresponding embodiments with respect to the arrangement of the Abstimmelements to the first and / or second inner conductor and the arrangement of the two inner conductors to each other are dependent on the frequency range over which the high-frequency filter must be tuned.

Preferably, the inner conductor hole widened in the direction of the insertion, ie in the direction of the outside of the outer conductor housing. This broadening can be taped or conical in longitudinal section, for example. A parabolic broadening is also possible. This not only facilitates the insertion of the Abstimmelements, but this broadening can also serve to facilitate the inclusion of adhesive, by which the tuning element permanently fixed in the inner conductor hole can be fixed.

It is also possible that the tuning element has a first sliding surface as a peripheral surface, which extends at least in the region in which the tuning element is guided within the inner conductor bore. In the inner conductor bore is preferably located as an inner wall, a second sliding surface, wherein the friction coefficients of the first and second sliding surface must be selected such that the tuning element is securely disposed within the inner conductor bore and only by the use of a stepping motor or a linear motor the insertion is axially displaceable.

The bush or sleeve is preferably elastic and preferably further consists of a dielectric material. The socket serves to produce a non-positive connection to the tuning element. The socket may for example consist of a rubber compound. The socket is arranged positively or non-positively within the inner conductor bore of the first or second inner conductor. Instead of a bush, as explained, a sleeve may be used, wherein the sleeve is pulled over the tuning element, before the tuning element in the inner conductor bore is used. Instead, a socket is already in the inner conductor bore before the tuning element is inserted. Both the sleeve and the sleeve, which are preferably both made of a dielectric material, also allow the tuning element to be formed of an electrically conductive material instead of a dielectric material of which it is preferably formed.

When using a bush, the ends of which preferably have an at least partially circumferential flange, so that the bushing is arranged axially immovably within the inner conductor bore of the first or second inner conductor. A first end of the sleeve rests with its at least partially circumferential flange on a shoulder which is disposed within the inner conductor bore of the first or second inner conductor. The inner conductor bore therefore has a shoulder and is therefore at least partially tapered. A second end of the bush is supported with its at least partially also flanged flange on an outer side of the outer conductor housing at the insertion opening of the inner conductor bore.

The tuning element also has a fastener at the end closer to the insertion opening. This fastening device serves to be able to connect an aid to the tuning element, wherein via this aid a tensile or compressive movement can be transmitted to the tuning means, whereby it can be moved back and forth within the inner conductor bore. In this Aid is preferably an adjusting device which has a coupling device, wherein the coupling device is connected to the fastening device. At least part of the coupling device can be introduced or inserted from outside the insertion opening. About this connection between the fastening device and the coupling device can then be said tensile, as well as compressive forces are transmitted. The adjusting device also additionally includes the linear or stepper motor.

The connection between the fastening device and the coupling device is designed as a releasable connection. For this purpose, in particular a bayonet connection, or a screw, or a lock, or a vacuum connection in question.

In order to ensure a smooth displacement of the tuning element within the inner conductor bore, the fastening device and the tuning element are preferably formed in one piece.

Figuren 1A, 1B:

verschiedene räumliche Darstellungen eines Längsschnitts durch das erfindungsgemäße Hochfrequenzfilter mit einem gewindelosen Abstimmelement;

Figuren 2A, 2B:

verschiedene zweidimensionale Längsschnitte durch die Ausführungsbeispiele des erfindungsgemäßen Hochfrequenzfilters aus den Figuren 1A und 1B;

Figur 3A:

eine Seitenansicht von einem Ausführungsbeispiel eines Abstimmelements, wobei ein Ende des Abstimmelements ein Übermaß und ein anderes Ende ein Untermaß bezogen auf eine Innenleiter-Bohrung aufweist;

Figur 3B:

ein Querschnitt durch das Ende mit dem Übermaß des Abstimmelements aus Figur 3A;

Figur 4A:

eine Seitenansicht von einem weiteren Ausführungsbeispiel des Abstimmelements, wobei ein Ende des Abstimmelements geschlitzt ausgeführt ist und sich nach außen hin verbreitert und dadurch in seinem Ende elastisch ist;

Figur 4B:

eine um einen bestimmten Drehwinkel gedrehte Seitenansicht des Abstimmelements aus Figur 4A, wobei eine Eingriffsöffnung für eine Koppeleinrichtung sichtbar ist;

Figur 5A:

einen Längsschnitt durch ein weiteres Ausführungsbeispiel des erfindungsgemäßen Hochfrequenzfilters, wobei in die Innenleiter-Bohrung eine Buchse eingesetzt ist, zwischen der und dem Abstimmelement ein Reibschluss vorliegt;

Figur 5B:

einen Querschnitt durch die Buchse aus Figur 5A;

Figur 6:

einen Längsschnitt durch ein weiteres Ausführungsbeispiel des erfindungsgemäßen Hochfrequenzfilters, wobei beide Innenleiter überlappungsfrei zueinander angeordnet sind;

Figur 7:

einen Längsschnitt durch ein weiteres Ausführungsbeispiel des erfindungsgemäßen Hochfrequenzfilters, wobei die Buchse an der Einführöffnung als elastischer Ring ausgebildet ist;

Figur 8:

eine räumliche Darstellung einer Verbindung, die von der Befestigungseinrichtung und der Koppeleinrichtung in Form eines Bajonettverschlusses gebildet wird;

Figuren 9A, 9B und 9C:

verschiedene Längsschnitte durch ein Ausführungsbeispiel des erfindungsgemäßen Hochfrequenzfilters, wobei die Verbindung zwischen der Befestigungseinrichtung und der Koppeleinrichtung eine Verriegelung ist und wobei mittels eines Klebers das Abstimmelement innerhalb der Innenleiter-Bohrung fixiert wird;

Figur 10:

ein Längsschnitt durch ein Ausführungsbeispiel des erfindungsgemäßen Hochfrequenzfilters, wobei die Verbindung zwischen der Befestigungseinrichtung und der Koppeleinrichtung eine Schraubverbindung ist;

Figur 11:

ein Längsschnitt durch ein weiteres Ausführungsbeispiel des erfindungsgemäßen Hochfrequenzfilters, wobei die Verbindung zwischen der Befestigungseinrichtung und der Koppeleinrichtung eine Vakuumverbindung ist; und

Figur 12:

ein Flussdiagramm welches erläutert, wie ein Abgleich des erfindungsgemäßen Hochfrequenzfilters erfolgt.

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, 1B:

different spatial representations of a longitudinal section through the inventive High frequency filter with a threadless tuning element;

FIGS. 2A, 2B:

different two-dimensional longitudinal sections through the embodiments of the high-frequency filter according to the invention from the Figures 1A and 1B ;

FIG. 3A:

a side view of an embodiment of a Abstimmelements, wherein one end of the Abstimmelements an oversize and another end undersized with respect to an inner conductor bore;

FIG. 3B:

a cross section through the end with the excess of the Abstimmelements FIG. 3A ;

FIG. 4A

a side view of a further embodiment of the Abstimmelements, wherein one end of the Abstimmelements is slotted and widened towards the outside and thereby is elastic in its end;

FIG. 4B:

a rotated by a certain angle of rotation side view of the Abstimmelements FIG. 4A wherein an engagement opening for a coupling device is visible;

FIG. 5A

a longitudinal section through a further embodiment of the invention Hochfrequenzfilters, wherein in the inner conductor bore a bushing is inserted, between which and the tuning element is a frictional engagement;

FIG. 5B:

a cross section through the bush of Figure 5A;

FIG. 6:

a longitudinal section through a further embodiment of the high-frequency filter according to the invention, wherein both inner conductors are arranged without overlapping to each other;

FIG. 7:

a longitudinal section through another embodiment of the high-frequency filter according to the invention, wherein the socket is formed at the insertion opening as an elastic ring;

FIG. 8:

a perspective view of a connection, which is formed by the fastening device and the coupling device in the form of a bayonet closure;

FIGS. 9A, 9B and 9C:

various longitudinal sections through an embodiment of the high-frequency filter according to the invention, wherein the connection between the fastening device and the coupling device is a lock and wherein by means of an adhesive, the tuning element is fixed within the inner conductor bore;

FIG. 10:

a longitudinal section through an embodiment of the high-frequency filter according to the invention, wherein the connection between the fastening device and the coupling device is a screw connection;

FIG. 11:

a longitudinal section through a further embodiment of the high-frequency filter according to the invention, wherein the connection between the fastening device and the coupling device is a vacuum connection; and

FIG. 12:

a flowchart which explains how an adjustment of the high-frequency filter according to the invention takes place.

Figure 1A shows a spatial representation of a longitudinal section through the high-frequency filter 1 according to the invention with a threadless tuning element 9. The high-frequency filter 1 comprises at least one resonator 2, which has a first inner conductor 3 and an outer conductor housing 4. The outer conductor housing 4 comprises a housing bottom 5, a housing cover 5 spaced apart from the housing cover 6 and a circumferential between the housing bottom 5 and the housing cover 6 housing wall 14. The first inner conductor 3 is electrically connected to the housing bottom 5 and extends in the axial direction of the housing bottom 5 in Direction of the housing cover 6. In this case, the first inner conductor 3 ends at a distance in front of the housing cover 6 and / or is galvanically isolated from the housing cover 6. The first inner conductor 3 and the housing bottom 5 are preferably formed in one piece. However, a multi-part education would also be possible.

The second inner conductor 7 is galvanically connected to the housing cover 6 and extends in the axial direction from the housing cover 6 in the direction of the housing bottom 5. Both the first, and the second inner conductor 3, 7 are axially immovable. Both inner conductors 3, 7 run towards each other and are aligned coaxially with each other.

The first inner conductor 3 and the housing bottom 5 are integrally formed. A multi-part training would also be possible. The same applies to the second inner conductor 7 with the housing cover 6. The first inner conductor 3 has an inner conductor bore 8. The inner conductor bore 8 of the first inner conductor 3 passes through the outer conductor housing 4 and opens into an insertion opening 13 in the embodiment Figure 1A the housing bottom 5 is penetrated by the inner conductor bore 8.

A tuning element 9 is arranged axially displaceable within the inner conductor bore 8 of the first inner conductor 3. The tuning element 9 is designed and / or arranged such that a portion of the tuning element 9 is immersed to different degrees in the free space between the two inner conductors 3, 7. In the section of the Abstimmelements 9, which dips into the free space between the two inner conductors 3, 7, it is preferably an end 11 of the Abstimmelements 9, which is remote from the other end 10, which is arranged closer to the insertion opening 13.

In the embodiment Figure 1A the inner conductor bore 8 is formed solely in the first inner conductor 3. However, this inner conductor bore 8 could also, as will be explained below, be formed on the second inner conductor 7, in which case the housing cover 6 would be penetrated by the inner conductor bore and would have the insertion opening 13.

The tuning element 9 is formed in this case as a hollow cylinder, wherein in the hollow cylinder, preferably the second inner conductor 7 is inserted. At the other end 10, which is closer to the insertion opening 13 in the inserted state of the tuning element 9, a fastening device 12 is formed. As will be explained in more detail below, this fastening device 12 serves to be able to displace the tuning element 9 axially within the inner conductor bore 8.

The tuning element 9 is preferably pressed into the inner conductor bore 8, or injected with compressed air. The outer diameter of the Abstimmelements 9 is dimensioned such that there is a frictional connection between the tuning element 9 and the inner wall of the inner conductor bore 8, so that the tuning element 9 can not move independently within the inner conductor bore. For this purpose, the outer peripheral surface of the Abstimmelements 9, as well as the inner wall of the inner conductor bore 8 to consider. Both surfaces can be seen as a sliding surface, wherein the side peripheral surface of the Abstimmelements 9 can be considered as a first sliding surface and the inner wall of the inner conductor bore 8 as a second sliding surface. The friction coefficient of both sliding surfaces must be chosen such that a corresponding adhesion is present.

Within Figure 1A is the inner wall, so the second sliding surface of the inner conductor bore 8 smooth. This means that the inner conductor bore 8 has no thread.

The tuning element 9 is galvanically separated from the first and second inner conductor 3, 7.

The FIG. 1B shows a spatial representation of a longitudinal section through a further embodiment of the high-frequency filter according to the invention 1. In contrast to the embodiment of Figure 1A the second inner conductor 7 also has an inner conductor bore 15. The tuning element 9 is located in the inner conductor bore 8 of the first inner conductor 3. The tuning element 9 is designed such that it covers not only a part of the inner wall of the inner conductor bore 8, but also the end face of the first inner conductor 3 and the part of Side peripheral surface of the first inner conductor 3, which adjoins directly to the front side. The tuning element 9 therefore has a kind of mushroom shape. In this case, the tuning element 9 is arranged in the inner conductor bore 8 of the first inner conductor 3 and protrudes out of this and into the inner conductor bore 15 of the second inner conductor 7, wherein both inner conductors 3, 7 do not touch at their ends. Of course, it could also be the case that the tuning element 9 is arranged in the inner conductor bore 15 of the second inner conductor 7.

The tuning element 9 preferably extends over more than 30%, more preferably over more than 40%, more preferably over more than 50% of the length of the inner conductor bore 8 of the first inner conductor 3. It may also be over more than 100% of the length extend and protrude from the inner conductor bore 8 of the first inner conductor 3 at the insertion opening 13. However, it may also be that the tuning element 9, the insertion as in FIG. 1B not reached and ends within the inner conductor bore 8 of the first inner conductor 3.

The inner conductor bore 15 of the second inner conductor 7 has, in this embodiment, a larger diameter than the first inner conductor 3. As a result, the first inner conductor 3 in the inner conductor bore 15 of the second inner conductor 7 at least partially immerse, wherein between the two inner conductors 3, 7, a clearance space 16 is formed as shown in FIG FIG. 2B is shown.

Within FIG. 2B It can also be seen that a two-part construction of the tuning element 9 is possible. A first part is located inside the inner conductor bore 8 of the first inner conductor 3, whereas a second part is located outside the inner conductor bore 8 and covers, for example, the front side of the first inner conductor 3 and the part of the side peripheral surface which adjoins the front side , Of course, the tuning element 9 may also be integrally formed. FIG. 2B shows a two-dimensional representation of a longitudinal section of the embodiment of the high-frequency filter 1, which in FIG. 1B is shown.

Conversely shows FIG. 2A a two-dimensional representation of a longitudinal section of the embodiment of the high-frequency filter 1, as in Figure 1A is shown. Within FIG. 2A the tuning element 9 extends almost to the housing cover. 6

In principle, the tuning element 9 prevents the first inner conductor 3 and the second inner conductor 7 from overlapping directly.

This means that neither the end faces of the first or second inner conductor 3, 7 face without separation by the tuning element 9, nor that two side peripheral surfaces of the first or second inner conductor 3, 7 directly opposite to a separation by the tuning element 9.

FIG. 3A shows a side view of an embodiment of a Abstimmelements 9, wherein one end 10 of the Abstimmelements 9 an oversize and the rest of the Abstimmelements 11 and thus, inter alia, another end 11 undersized with respect to an inner conductor bore 8 has. FIG. 3B shows a corresponding cross section through the end 10 of the Abstimmelements 9, where the excess is present. The excess results from an at least partially enlarged diameter in the form of elevations 21, which in the longitudinal direction, ie extend in the axial direction of the tuning element 9. These elevations 21 preferably extend over a length of less than one third, more preferably less than a quarter of the total length of the tuning element 9.

These elevations 21 can be added, for example, within a milling or casting process, in which the tuning element 9 is basically produced.

Furthermore, a mounting opening 20 is still shown, which serves to receive a lock 45, as will be described in the further drawings. The end 10, which has the attachment opening 20, is also regarded as a fastening device 12.

The elevations 21 of the Abstimmelements 9 from FIG. 3A are preferably elastic.

The tuning element 9 is preferably made of a dielectric material, in particular of a ceramic or a plastic.

The FIGS. 4A and 4B show a side view of a further embodiment of the Abstimmelements 9, wherein the end 10 of the Abstimmelements 9 has a slot 25 in the longitudinal direction and widens to the outside. This slot 25 causes the end 10 of the Abstimmelements 9, which, in the inserted state, preferably closer to the insertion opening 13 is arranged, as the other end 11, elastic properties and can bend in the radial direction on the longitudinal axis, wherein the longitudinal axis extends centrally through the tuning element 9.

The area with the enlarged diameter is in the FIGS. 3A and 4A arranged at the end 10 of the tuning element 9. However, it would also be conceivable that the region with the widened diameter is located in the middle of the tuning element 9.

The FIG. 4B shows another side view of the Abstimmelements 9, as in FIG. 4A is shown, only that within FIG. 4B the tuning element 9 has been rotated by approximately 90 °. In this view, also the attachment opening 20 can be seen, which in turn is part of the fastening device 12 of the tuning element 9 and over which, as will be explained later, the tuning element 9 can be moved axially within the inner conductor bore 8.

FIG. 5A shows a longitudinal section through a further embodiment of the high-frequency filter 1 according to the invention, wherein in the inner conductor bore 8 of the first inner conductor 3, a socket 31 is inserted, in which the tuning element 9 is used, wherein between the socket 31 and the tuning element 9 is a positive connection.

The bushing 31 is preferably made of an elastic material. The bush 31 is preferably formed in one piece, with a multi-part design would also be possible. In the event that the socket 31 is formed of a dielectric material, the tuning element can 9 may also be formed of an electrically conductive material. However, the tuning element 9 preferably also consists of a dielectric material.

The bush 31 is arranged within the inner conductor bore 8 of the first or second inner conductor 3, 7 positively or non-positively. Both ends of the bush 31 have, as in cross section in FIG. 5B shown, an at least partially encircling flange 33. This partially circumferential flange 33 is responsible for the bushing 31 being arranged axially non-displaceable within the inner conductor bore 8 of the first inner conductor 3. The first end of the bush 31 is supported with its at least partially circumferential flange 33 on a shoulder 32 of the inner conductor bore 8 of the first inner conductor 3 within this. The second end of the bush 31 is supported with its at least partially circumferential flange 33 on the outside of the outer conductor housing 4 at the insertion opening 13 of the inner conductor bore 8 of the first inner conductor 3 from. The bush 31 is preferably pressed.

Instead of a bushing 31, which is inserted into the inner conductor bore 8 before inserting the tuning element 9, it would also be possible to place a sleeve on the tuning element 9, wherein the tuning element 9 is inserted together with the sleeve in the inner conductor bore 8 ,

Within FIG. 5A The two inner conductors 3, 7 partially overlap, the tuning element 9 being formed in the overlapping region.

Within FIG. 5A is also shown that the tuning element 9 at the end 10, which is the most spaced from the insertion opening 13, a receiving opening 30 is formed. Into the receiving opening 30 of the tuning element 9, the second inner conductor 7 is immersed.

Of course, it would also be possible for the tuning element 9 to be inserted into the inner conductor bore 15 of the second inner conductor 7, in which case the first inner conductor 3 would dip into the receiving opening 30.

FIG. 6 shows an embodiment of the high-frequency filter 1 according to the invention, which has strong similarity to the embodiment of the high-frequency filter 1 according to the invention, which in FIG. 5A was shown. The only difference is that both inner conductors 3, 7 do not overlap.

FIG. 7 shows a longitudinal section through a further embodiment of the high-frequency filter 1 according to the invention, wherein the bushing 31 is formed at the insertion opening 13 as an elastic ring. The tuning element 9 is again formed in the inner conductor bore 8 of the first inner conductor 3 in this case. Only the view is rotated. However, the tuning element 9 could also be formed in the inner conductor bore 15 of the second inner conductor 7. The bushing 31, which has the shape of an elastic ring, protrudes at least partially into the inner conductor bore 8 of the first inner conductor 3. When inserting the tuning element 9 in the inner conductor bore 8, the ring is therefore widened and provides due to its elasticity for a Frictional connection to the tuning element 9. The bushing 31 is preferably connected via an adhesive connection firmly with the opposite to the inner conductor bore 8 widened insertion opening 13. In this case, the socket 31 is fixedly connected to the housing bottom 5, but it could just as firmly connected to the housing cover 6.

FIG. 8 shows a spatial representation of a compound, which is formed by the fastening device 12 and the coupling device 41 in the form of a bayonet closure. The tuning element 9 has at the end 10, which in the inserted state of the insertion opening 13 is closest to the fastening device 12. The fastening device 12 consists of a longitudinal slot and a transverse slot which are interconnected. This longitudinal slot and this transverse slot appear at preferably two points on the side peripheral surface of the Abstimmelements 9. The coupling device 41 preferably has at two points a region with a widened diameter, in particular a radially outwardly pointing pin. This radially outwardly pointing pin corresponds to the cylindrical coupling device 41 in such a way that the coupling device 41 can be introduced into the tuning element 9 designed as a hollow cylinder, wherein the pin of the coupling device 41 is guided stop-limited within the longitudinal slot and thus telescoping the coupling device 41 into the tuning element 9 allowed. Once the stop limit at the end of the longitudinal slot is reached by the pin of the coupling device 41, causes a rotation of the coupling device 41 clockwise or counterclockwise a closure of the bayonet lock. In the following slides the pin of the coupling device 41 in the transverse slot of the Abstimmelements 9. The pin is mounted stop limit, so that both tensile and compressive forces can be transmitted without delay from the coupling device 41 on the tuning element 9.

The coupling device 41 is connected to a stepper motor or to a linear motor.

The bayonet catch is a detachable connection. At least part of the coupling device 41 is located outside the insertion opening 13, but can be introduced into this and into the inner conductor bore 8.

The longitudinal and the transverse slot could of course also be formed in the coupling device 41, in which case the pin would have to be formed in the tuning element 9.

The FIGS. 9A . 9B and 9C show various longitudinal sections through an embodiment of the high-frequency filter 1 according to the invention, wherein the connection between the fastening device 12 and the coupling device 41 is a lock 45 and wherein by means of an adhesive 47, the tuning element 9 is fixed within the inner conductor bore 8.

Figure 9A shows that one end of the coupling device 41, which comes into contact with the tuning element 9, is elastically formed and radially inwardly, ie to the longitudinal axis, which passes through the coupling device 41, can be bent. In the embodiment of Figure 9A, the end of the coupling device 41 is not bent in the direction of the longitudinal axis, but is in a relaxed state. At the outer periphery of the end of the coupling device 41 is at least one pin. Within the embodiment of Figure 9A it's two pens. These two pins engage in the mounting holes 20, as for example in the FIGS. 3A and 4B are shown. In this so-called lock 45, the coupling device 41 can be inserted into the at least partially designed as a hollow cylinder tuning element 9 and firmly connected by a click connection so that a transfer of tensile or compressive forces can be done without delay.

A gap between the outer peripheral surface of the Abstimmelements 9 and the inner wall of the inner conductor bore 8 is shown exaggerated thickness. As before, there is a frictional connection between the tuning element 9 and the inner conductor bore 8. Of course, the tuning element 9 could also be introduced into the inner conductor bore 15 of the second inner conductor 7 and not be introduced into the inner conductor bore 8 of the first inner conductor 3 as here.

Furthermore, an adhesive device 44 is shown, via which an adhesive 47 can be introduced into the insertion opening 13. The adhesive device 44 is preferably also part of the adjusting device.

Within FIG. 9B was by means of the coupling device 41, the tuning element 9 in the desired position placed inside the inner conductor bore 8 of the first inner conductor 3. The end of the coupling device 41, which is in contact with the tuning element 9, is tapered, so has contracted in the direction of the longitudinal axis. The pins, which are attached to the side peripheral surface of the end of the coupling device 41, are no longer in engagement with the mounting holes 20 of the fastening device 12 of the Abstimmelements 9. The coupling device 41 can be removed by axial displacement from the insertion port 13 of the high-frequency filter 1.

FIG. 9C shows the coupling device 41, wherein the end has contracted in the direction of the longitudinal axis. Preferably, the end of the coupling device 41 in the form of tweezers, wherein on the side peripheral surface, the spacers, so the pins are mounted, which engage in the mounting holes 20. The tips of the coupling device 41 can pull together until they touch each other. Within FIG. 9C In addition, the adhesive 47 has already been introduced in order to connect the tuning element 9 with the inner wall of the inner conductor bore 8 of the first inner conductor 3.

The end 10 of the tuning element 9, which is closer to the insertion opening 13, preferably has a smaller diameter than the tuning element 9 has at the other end 11 or in the middle. This results in a cavity between the tuning element 9 and the inner wall of the inner conductor bore 8 of the first inner conductor 3, in which the adhesive 47 can be inserted.

FIG. 10 shows a further embodiment of the high-frequency filter 1 according to the invention, wherein the connection between the fastening device 12 on the tuning element 9 and the coupling device 41 is a screw 50. For this purpose, the tuning element 9 at the end 10, which is closer to the insertion opening 13, an internal thread into which the end of the coupling device 41, which includes an external thread, can engage. It would also be possible for the tuning element 9 to have an external thread and to be correspondingly connected to the coupling device 41.

FIG. 11 shows a further embodiment of the high-frequency filter 1 according to the invention, wherein the connection between the tuning element 9, at the fastening device 12, and the coupling device 41 is made via a vacuum. For this purpose, the end of the coupling device 41, which is in contact with the tuning element 13, vacuum nozzles 60, which are capable of sucking air. These vacuum nozzles 60 are in contact with a corresponding engagement surface on the fastening device 12 of the Abstimmelements 9. There should be a clearance fit between the tuning element 9 and the inner conductor bore 8 of the first inner conductor 3. The gap between the tuning element 9 and inner conductor bore 8 of the first inner conductor 3 is finally filled with the adhesive 47. In this case, an adhesive 47 with suitable viscosity must be used. Via the vacuum, the tuning element 9 is held on the vacuum nozzles 60, so that via a movement of the vacuum nozzles 60, the tuning element 9 can be used for tuning closer to the insertion opening 13. To that Tuning element 9 further away from the insertion opening 13, press the vacuum nozzles 60 mechanically to the fastening device 12 and push so the tuning element 9 further into the resonator 2 inside.

It is also possible that a part of the tuning element 9, in particular the end 10, which comes into contact with the coupling device 41, protrudes from the outer conductor housing 4.

The fastening device 12 and the tuning element 9 are preferably formed in one piece.

FIG. 12 shows a method for adjusting the high-frequency filter according to the invention 1. Within the process step S ₁ , the high-frequency filter is closed. This means that the corresponding input terminals and the housing cover 6 are placed. The high frequency filter 1 is thereby closed high frequency tight. For this purpose, the screw are tightened.

Within a further method step S ₂ , the connection between the fastening device 12 of the tuning element 9 is made with the coupling device 41 of the adjusting device. As already explained, this connection can be a bayonet connection 40 or a screw connection 50 or a lock 45 or a vacuum connection.

In addition, in the method step S _3, the tuning element 9 is inserted into the inner conductor bore 8, 15 of the first or second inner conductor 3, 7. This insertion can be done by pressing or by shooting by means of compressed air.

The steps S ₁ , S ₂ , S ₃ can be performed in any order.

Subsequently, method step S _{4 is} carried out. Within the method step S ₄ , the filter properties are measured. This includes, for example, the measurement of the resonance frequency.

Subsequently, the method step S _{5 is} carried out, in which the tuning element 9 is displaced in the direction of the insertion opening 13 or away from the insertion opening 13 by means of the adjusting device. With a linear or stepper motor, step sizes on the order of a few micrometers can be selected.

Once the tuning element 9 has been traversed by a certain travel, the process step S _{6 is} executed. Within method step S ₆ , method steps S ₄ and S _{5 are} repeated until the desired filter properties are achieved.

As soon as this is the case, the method step S _{7 is} carried out, in which the tuning element 9 is fixed by means of an adhesive bond in the inner conductor bore 8, 15 of the first or second inner conductor 3, 7.

Before or after the method step S ₇ , the connection between the coupling device 41 and the fastening device 12 again separated and the coupling device 41 are removed from the insertion opening 13. The invention is not limited to the described embodiments, as the invention is defined only by the following claims.

Claims (15)

1. High-frequency filter (1) of a coaxial construction, wherein the high-frequency filter (1) has the following features:

   - at least one resonator (2) having a first inner conductor (3) and having an outer conductor housing (4);

   - the outer conductor housing (4) comprises a housing bottom (5), a housing cover (6) spaced apart from the housing bottom, and a peripheral housing wall (14) between the housing bottom (5) and the housing cover (6);

   - the first inner conductor (3) is galvanically connected to the housing bottom (5) and extends in the axial direction from the housing bottom (5) towards the housing cover (6);

   - the first inner conductor (3) ends at a distance in front of the housing cover (6) and/or is galvanically isolated from the housing cover (6);

   - the resonator (2) comprises a second inner conductor (7);

   - the second inner conductor (7) is galvanically connected to the housing cover (6) and extends in the axial direction from the housing cover (6) towards the housing bottom (5);

   - the first and second inner conductors (3, 7) are axially immovable;

   - the first and second inner conductors (3, 7) are arranged coaxially to one another;

   - the first and/or second inner conductor(s) (3, 7) have an inner conductor bore (8, 15);

   - the inner conductor bore (8, 15) of the first or second inner conductor (3, 7) passes through the outer conductor housing (4) and opens into an insertion opening (13);

   - a tuning element (9) is arranged inside the inner conductor bore (8, 15) of the first or second inner conductor (3, 7) in such a way that the tuning element (9) is axially displaceable during tuning;

   - the tuning element (9) is designed and/or arranged in such a way that a portion of the tuning element (9) dips at different depths into a free space between the two inner conductors (3, 7),

   -

   A) a socket (31) or a sleeve is:

   a) positively or non-positively arranged inside the inner conductor bore (8) of the first inner conductor (3) between the first inner conductor (3) and the tuning element (9); or

   b) positively or non-positively arranged inside the inner conductor bore (15) of the second inner conductor (7) between the second inner conductor (7) and the tuning element (9); and or

   B) the tuning element (9) has a region with a widened diameter, wherein this region is situated:

   a) in the centre of the tuning element (9); and/or

   b) at the end (10) of the tuning element (9) which is arranged closer to the insertion opening (13),

   wherein the region with the widened diameter is resilently deformable in the radial direction to the longitudinal axis which passes centrally through the tuning element (9); and

   - the tuning element (9) is fixed inside the inner conductor bore (8, 15) of the first or second inner conductor (3, 7) by means of an adhesive bond (47), wherein the adhesive bond (47) is applied to the end (10) of the tuning element (9) which is closer to the insertion opening (13).
2. High-frequency filter according to claim 1, characterised by the following feature:

   - the first inner conductor (3) and the housing bottom (5) are formed in one piece and/or the second inner conductor (7) and the housing cover (6) are formed in one piece.
3. High-frequency filter according to either claim 1 or claim 2, characterised by following features:

   - an inner wall of the inner conductor bore (8) of the first inner conductor (3) is smooth; and/or

   - an inner wall of the inner conductor bore (15) of the second inner conductor (7) is smooth.
4. High-frequency filter according to any of the preceding claims, characterised by the following features:

   - the tuning element (9) is electrically conductive;

   - the tuning element (9) is galvanically isolated from the first and second inner conductors (3, 7).
5. High-frequency filter according to any of the preceding claims, characterised by the following features:

   - both ends of the socket (31) have an at least partially circumferential flange (33), so that the socket is arranged axially and non-displaceably inside the inner conductor bore (8, 15) of the first or second inner conductor (3, 7);

   - a first end of the socket (31) is supported with its at least partially circumferential flange (33) on a shoulder (32) of the inner conductor bore (8, 15) of the first or second inner conductor (3, 7) inside said inner conductor;

   - a second end of the socket (31) is supported with its at least partially circumferential flange (33) on the outside of the outer conductor housing (34) at the insertion opening (13) of the inner conductor bore (8, 15) of the first or second inner conductor (3, 7).
6. High-frequency filter according to any of the preceding claims, characterised by the following features:

   - the socket (31) is formed in one piece or in multiple pieces and/or consists of a resilient dielectric material and the tuning element (9):

   a) is formed in one piece or in multiple pieces; and/or

   b) consists of a dielectric material or an electrically conductive material;

   or

   - the tuning element (9):

   a) is formed in one piece or in multiple pieces; and/or

   b) consists of a dielectric material, in particular of a ceramic or a plastics material.
7. High-frequency filter according to any of the preceding claims, characterised by the following feature:

   - the first inner conductor (3) has an inner conductor bore (8) and the second inner conductor (7) has an inner conductor bore (15);

   - the tuning element (9) is arranged in the inner conductor bore (8) of the first inner conductor (3) and protrudes therefrom and into the inner conductor bore (15) of the second inner conductor (7), wherein both inner conductors (3, 7) do not touch at their end faces; or
   the tuning element (9) is arranged in the inner conductor bore (15) of the second inner conductor (7) and protrudes therefrom and into the inner conductor bore (8) of the first inner conductor (3), wherein both inner conductors (3, 7) do not touch at their end faces.
8. High-frequency filter according to claim 7, characterised by the following feature:

   - both inner conductors (3, 7) are arranged without overlapping each other, so that neither of the two inner conductors (3, 7) dips into the respective other inner conductor (7, 3).
9. High-frequency filter according to any of claims 1 to 6, characterised by the following feature:

   a) the inner conductor bore (8) of the first inner conductor (3) has a larger diameter than the second inner conductor (7);
   the second inner conductor (7) dips at least in part into the inner conductor bore (8) of the first inner conductor (3), wherein a space (16) is formed between the two inner conductors (3, 7);
   the tuning element (9) is formed and/or arranged such that a portion of the tuning element (9) dips at different depths into the free space (16) between the two inner conductors (3, 7); or

   b) the inner conductor bore (15) of the second inner conductor (7) has a larger diameter than the first inner conductor (3);
   the first inner conductor (3) dips at least in part into the inner conductor bore (15) of the second inner conductor (7), wherein a space (16) is formed between the two inner conductors (3, 7);
   the tuning element (9) is designed and/or arranged such that a portion of the tuning element (9) dips at different depths into the free space (16) between the two inner conductors (3, 7); or/and

   c) the inner conductor bore (8, 15) of the first or second inner conductor (3, 7) widens in the direction of the insertion opening (13).
10. High frequency filter according to claims 1 to 6, characterised by the following features:

    - the tuning element (9) has a receiving opening (30) at the end (11) which is furthest from the insertion opening (13);

    - the tuning element (9) is arranged in the inner conductor bore (8) of the first inner conductor (3), wherein the second inner conductor (7) dips into the receiving opening (30) of the tuning element (9); or
    the tuning element (9) is arranged in the inner conductor bore (15) of the second inner conductor (7), wherein the first inner conductor (3) dips into the receiving opening (30) of the tuning element (9).
11. High-frequency filter according to any of the preceding claims, characterised by the following features:

    - the tuning element (9) has a fastening device (12) at the end (10) which is closer to the insertion opening (13);

    - the fastening device (12) can be connected to a coupling device (41) of an adjusting device, wherein at least part of the coupling device (41) can be inserted into said fastening device from outside the insertion opening (13);

    - both tensile and compressive forces can be transmitted via the connection between the fastening device (12) and the coupling device (41), as a result of which the tuning element (9) is movable towards the insertion opening (13) or away from the insertion opening (13) inside the inner conductor bore (8, 15) of the first or second inner conductor (3, 7).
12. High-frequency filter according to claim 11, characterised by the following feature:

    - the connection between the fastening device (12) and the coupling device (41) can be configured as a detachable connection, in particular as a:

    a) bayonet connection (40); or

    b) screw connection (50); or

    c) lock (45); or

    d) vacuum connection.
13. High-frequency filter according to either claim 11 or claim 12, characterised by the following feature:

    - the fastening device (12) and the tuning element (9) are formed in one piece.
14. Method for tuning a high-frequency filter (1), wherein the high-frequency filter (1) has the following features:

    - at least one resonator (2) having a first inner conductor (3) and having an outer conductor housing (4);

    - the outer conductor housing (4) comprises a housing bottom (5), a housing cover (6) spaced apart from the housing bottom, and a peripheral housing wall (14) between the housing bottom (5) and the housing cover (6);

    - the first inner conductor (3) is galvanically connected to the housing bottom (5) and extends in the axial direction from the housing bottom (5) towards the housing cover (6);

    - the first inner conductor (3) ends at a distance in front of the housing cover (6) and/or is galvanically isolated from the housing cover (6);

    - the resonator (2) comprises a second inner conductor (7);

    - the second inner conductor (7) is galvanically connected to the housing cover (6) and extends in the axial direction from the housing cover (6) towards the housing bottom (5);

    - the first and second inner conductors (3, 7) are axially immovable;

    - the first and second inner conductors (3, 7) are arranged coaxially to one another;

    - the first and/or second inner conductor(s) (3, 7) have an inner conductor bore (8, 15);

    - the inner conductor bore (8, 15) of the first or second inner conductor (3, 7) passes through the outer conductor housing (4) and opens into an insertion opening (13);

    - a tuning element (9) is arranged axially displaceably inside the inner conductor bore (8, 15) of the first or second inner conductor (3, 7);

    - the tuning element (9) is designed and/or arranged in such a way that a portion of the tuning element (9) dips at different depths into a free space between the two inner conductors (3, 7),

    -

    A) a socket (31) or a sleeve is:

    a) positively or non-positively arranged inside the inner conductor bore (8) of the first inner conductor (3) between the first inner conductor (3) and the tuning element (9); or

    b) positively or non-positively arranged inside the inner conductor bore (15) of the second inner conductor (7) between the second inner conductor (7) and the tuning element (9); and or

    B) the tuning element (9) has a region with a widened diameter, wherein this region is situated:

    a) in the centre of the tuning element (9); and/or

    b) at the end (10) of the tuning element (9) which is closer to the insertion opening (13),

    wherein the region with the widened diameter is resiliently deformable in the radial direction to the longitudinal axis which passes centrally through the tuning element (9);

    having the following method steps:

    - closing (S₁) the high-frequency filter (1);

    - producing (S₂) a connection between a fastening device (12) of the tuning element (9) and a coupling device (41) of the adjusting device,

    - inserting (S₃), in particular pressing the tuning element (9) into the inner conductor bore (8, 15) of the first or second inner conductor (3, 7);

    wherein the method steps of closing (S₁), producing (S₂) and inserting (S₃) are executable in any order;

    - measuring (S₄) the filter characteristics;

    - axially displacing (S₅) the tuning element (9) inside the inner conductor bore (8, 15) of the first or second inner conductor (3, 7) towards the insertion opening (13) or away from the insertion opening (13) by means of the coupling device (41) of the adjusting device;

    - repeating (S₆) the method steps of measuring (S₄) and displacing (S₅) until the high-frequency filter (1) has the desired filter characteristics;

    - adding (S₇) an adhesive bond (47) between the tuning element (9) and the inner conductor bore (8, 15) of the first or second inner conductor (3, 7).
15. Method for tuning a high-frequency filter (1) according to claim 14, wherein the high-frequency filter (1) has the following features:

    - the tuning element (9) or the sleeve or surface coating thereon has a first sliding surface and the inner conductor bore (8, 15) or the socket (31) inserted therein or the surface coating of the first or second inner conductor (3, 7) situated therein has a second sliding surface, and

    a) the tuning element (9), in the method step of axially displacing (S₅), is displaceable with its first sliding surface along the second sliding surface inside the inner conductor bore (8, 15) of the first or second inner conductor (3, 7), and/or

    b) a threadless force or frictional engagement exists between the first sliding surface of the tuning element (9) and the second sliding surface of the inner conductor bore (8, 15) of the first or second inner conductor (3, 7).

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