DE102016000092A1 - Method for assembling high frequency filters - Google Patents

Abstract

A method is used for assembling high-frequency filters (1), wherein each high-frequency filter (1) has a high-frequency housing which has a housing body (2) and a housing cover (3) matched to the respective housing body (2). The housing body (2) comprises a housing bottom (4) and a between the housing bottom (4) and the housing cover (3) encircling housing wall (5). The high-frequency filter (1) comprises at least one coaxial resonator (61, 62, ..., 6n), which has a resonator chamber (71, 72, ..., 7n). In a method step, at least one electrical and / or geometric property of the housing body (2) is measured. Then, it is determined how large a measured value deviation of the measured value is from a reference value for this property of the housing body (2). Finally, a corresponding housing cover (3) is selected, so that in a combination of the housing body (2) with the selected housing cover (3) a frequency-dependent transmission curve of the resulting high-frequency filter (1) of a frequency-dependent reference transmission curve (17, 18) comes closest , whereby at least part of the measured value deviation is compensated.

Description

The invention relates to a method for assembling high frequency filters and a high frequency filter manufactured by this method.

In transmission technology, filters serve to pass through desired frequency ranges and to block unwanted frequency ranges. In the mobile sector, for example, this allows the use of a common antenna. Filters can then be used to separate the transmission path and the reception path.

Filters exist in different sizes. They may be formed within a chip, be constructed with discrete components on a printed circuit board or consist of milling or castings.

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. However, tolerances in the manufacturing process can not be avoided.

In order to achieve optimal filter results, however, a fine-tuning after production is necessary. Such a fine tuning usually takes place in that tuning elements are screwed into the resonator chambers, whereby the resonance frequency and the coupling bandwidths are changed.

From the DE 10 2010 056 048 A1 It is known that for fine tuning of the filter tuning elements are inserted at different depths in the resonators. 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.

A disadvantage of the DE 10 2010 056 048 A1 is that a sufficiently large voting range can not always be realized and that coordination is difficult to automate.

The object of the present invention is therefore to provide a method in which a high-frequency filter over the prior art is cheaper and easier to produce. In addition, it is the object of the invention to provide a high-frequency filter which is easier to tune than is possible in the known high-frequency filters of the prior art. The inventive method is solved by the claim 1. The high frequency filter according to the invention is constructed according to claim 12. Advantageous developments of the method according to the invention are described in the dependent claims.

The method according to the invention serves to assemble high-frequency filters, wherein each high-frequency filter has a high-frequency housing which has a housing body and a housing cover which is matched to the respective housing body. The housing body comprises a housing bottom and a housing wall surrounding the housing bottom and the housing cover, whereby the housing cover is spaced from the housing bottom of the housing body. The high frequency filter comprises at least one coaxial resonator having a resonator chamber. The coaxial resonator comprises at least one first inner conductor which is arranged in the resonator chamber, wherein the at least one 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 at least one first inner conductor terminates at a distance in front of the housing cover and / or is galvanically separated from the housing cover. The housing cover comprises at least one second inner conductor, which is galvanically connected to the housing cover and extends in the axial direction from the housing cover in the direction of the housing bottom. The at least one second inner conductor terminates at a distance from the housing bottom and / or is galvanically isolated from the housing bottom. To find a matching pair, consisting of housing body and housing cover, a series of process steps is performed. In one method step, at least one or more electrical and / or geometric property (s) of the housing body is measured. One obtains a measured value for this property of the housing body. In a further method step, it is determined how large a measured value deviation of the measured value for this characteristic of the housing body is from a reference value. In an additional method step, a corresponding housing cover, depending on the height of the measured value deviation, is selected or used from a group of at least two housing covers with different second inner conductors. In this case, that housing cover is selected or used by which, in combination with the housing body, a frequency-dependent transmission curve of the high-frequency filter formed therefrom comes closer or closest to a frequency-dependent reference transmission curve. With such a combination of housing body and housing cover, at least part of the measured value deviation is compensated.

It is particularly advantageous that the inventive method includes steps with which can be determined to what extent the housing body, which later forms the high-frequency filter together with the housing cover, deviates from a reference housing body. A reference housing body is a housing body to understand what it would look like if the manufacturing process (eg, an aluminum die casting process) did not have tolerances. On the basis of the measured value deviations determined, a housing cover can be selected, which in turn is designed in such a way that, when the selected cover is combined with the housing body, the manufacturing tolerances of the housing body can be compensated in the best possible way.

It is often the case that the manufacturing tolerances of the housing cover are smaller or do not have such a strong effect. This allows targeted housing cover with different geometric properties, such as the length and / or the thickness of the second inner conductor can be produced.

On the basis of the measured value deviations of the housing body from a reference housing body, a suitable housing cover can then be selected so that at least part of the frequency-dependent transmission curve of the high-frequency filter formed therefrom comes closest to the corresponding part of the frequency-dependent reference transmission curve. As a result, the measured value deviation between the actual housing body and the reference housing body can be at least partially compensated. This makes it possible that the number of tuning elements can be reduced, or that some or all tuning elements, as they are known from the prior art, can be omitted.

In an advantageous embodiment of the inventive method that housing cover is selected so that the then present frequency-dependent transmission curve of the manufactured high-frequency filter with the selected housing cover of the frequency-dependent Referenzdurchlasskurve at least in the passband and / or in the stopband closer or closest.

In another exemplary embodiment of the method according to the invention, the geometric property of the housing body is the diameter and / or the height of the at least one first inner conductor. In addition or alternatively, the geometric property of the housing body can also be the height of at least one coupling web and / or separating web, which extends away from the housing bottom and is located between two coaxial resonators. In addition or as an alternative thereto, the electrical property of the housing body may be at least one S-parameter (scattering parameter). On the basis of the measured properties of the housing body, a measured value deviation from the properties of a reference housing body can be determined, it being possible to determine the extent to which the frequency-dependent transmission curve of a high-frequency filter differs from the frequency-dependent reference transmission curve as a function of the height of the measured value deviation. Depending on the size of the measured value deviation, this can be at least partially and ideally completely compensated with a corresponding housing cover.

In an additional embodiment of the method according to the invention, the at least one measured value of the housing body to be measured is obtained from the at least one S parameter. This at least one measured value is, for example, in the frequency range of the passband and / or the stop band of the high-frequency filter. It can also correlate to the bandwidth of the passband and / or the stopband or to the center frequency and / or to the lower or upper limit frequency of the passband or stopband. Preferably, a plurality of measured values are recorded, so that the course of the transmission curve can be reproduced at least in the stopband or at least in the passband of the high-frequency filter. In this case, the measured value is a value indicating the attenuation of a signal transmitted by the high-frequency filter at a specific frequency or in a specific frequency characteristic.

In order to determine the electrical properties of the housing body, a test cover is placed on the housing body and pressed against this in a further embodiment of the method according to the invention. The test cover closes the resonator chamber completely or for the most part, so that no or as little as possible interference radiation from outside of the high-frequency filter enters this. The test cover is preferably always the same and is used for the measurement of preferably all housing bodies. By attaching or pressing the test cover on the housing body can be dispensed with a screw this with the housing body. This saves a lot of time. The test cover has at least one first capacitive coupling rod which is galvanically isolated from the test cover. This at least one first capacitive coupling rod is inserted adjacent to the at least one first inner conductor into the resonator chamber of the at least one coaxial resonator. By means of a vector network analyzer, the at least one S-parameter (scattering parameter) can be measured. It would also be possible To measure filter function, from which the at least one measured value is derived. The at least one first capacitive coupling rod is preferably firmly connected to the test cover, or always arranged at the same location on the test cover and is therefore always introduced in the different housing bodies in the same place in the resonator. The at least one capacitive coupling rod is preferably arranged only inside the resonator chamber.

In an additional embodiment of the method according to the invention, the test cover has at least one second capacitive coupling rod, which in turn is galvanically isolated from the test cover. This second capacitive coupling rod is also spatially and galvanically separated from the first capacitive coupling rod. The at least one second capacitive coupling rod is inserted adjacent to the at least one first inner conductor into the resonator chamber of the at least one coaxial resonator or adjacent to a further first inner conductor in the resonator chamber of a further coaxial resonator. By means of a vectorial network analyzer, for example, the forward or reverse transmission factor can then be measured. From this, the frequency-dependent transmission curve can be calculated, wherein this is preferably created only for a certain frequency range. The result of this frequency-dependent transmission curve can then be compared with a reference transmission curve. On the basis of the measured value deviations determined, the housing body is combined with a housing cover whose second inner conductor has a larger volume or a greater length or a smaller volume or a smaller length. In the event that the center frequency, or the upper or lower cutoff frequency to be raised upward, the housing body is combined with a housing cover whose second inner conductor has a smaller volume or is shorter than when the center frequency, or upper and / Lower limit frequency to be moved down. The frequency-dependent transmission curve is preferably the forward or reverse transmission factor between two ports (preferably between an input and an output) of the high-frequency filter.

In another embodiment of the method according to the invention, the at least one coaxial resonator into which the first capacitive coupling rod is inserted and the at least one other coaxial resonator into which the at least one second coupling rod is inserted are arranged adjacent to one another. However, they could also be separated from one another by at least one further coaxial resonator. It would also be possible for these resonators to be located at the beginning of a filter path and at the end of a filter path. In principle, it should be noted that the closer the capacitive coupling rod is to the corresponding inner conductor, the more accurate the measurement. However, the measurement becomes even more sensitive to tolerances.

In a supplementary embodiment of the method according to the invention, the test cover has at least as many capacitive coupling rods as there are coaxial resonators. At least one capacitive coupling rod is inserted in each of the coaxial resonators. In this case, a variety of scattering parameters can be determined. The frequency-dependent transmission curves derived therefrom, or parts of these, can in turn be compared with a multiplicity of reference transmission curves. The most suitable housing cover can be selected on the basis of the measured value deviations determined.

In another embodiment of the method according to the invention, the at least one capacitive coupling rod is inserted through an opening in the test cover into the resonator chamber of the at least one coaxial resonator. In addition or as an alternative, the at least one capacitive coupling rod protrudes by a predetermined distance from an inner surface of the test cover in the direction of the resonator chamber of the at least one coaxial resonator. This allows a simple construction of the test cover, whereby reproducible measurements are ensured.

The high-frequency filter according to the invention is produced by the method presented at the outset. The high-frequency filter comprises a housing body and a housing cover matched to the housing body. As a result, the number of tuning elements can be reduced, or they can be omitted entirely. When selecting the appropriate lid can also be spoken of a selective material supply in the production of coaxial filters.

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:

1 a spatial representation of a high frequency filter having a housing body and a housing cover;

2 : the optimal course of a frequency-dependent transmission curve of a high-frequency filter and deviations thereof, resulting from the fact that the housing body and the Housing cover manufacturing tolerances and are not matched;

3A : an enlarged representation of the frequency-dependent transmission curve in the passband 2 ;

3B : an enlarged representation of the frequency-dependent transmission curve in the stopband 2 ;

4A a possibility for measuring electrical properties of a housing body with a test cover;

4B . 4C : various possibilities for measuring geometric properties of a housing body;

5 a flowchart which explains how the appropriate selection of a housing cover can be made;

6 two different frequency-dependent transmission curves of a high-frequency filter, the high-frequency filter being closed once with a normal housing cover and once with a test cover;

7 : the optimum course of a frequency-dependent transmission curve of a high-frequency filter, which is closed with a test cover and deviations thereof, resulting from the fact that the housing body has manufacturing tolerances;

8th : an enlarged representation of the frequency-dependent transmission curve in the stopband 7 ; and

9 a spatial representation of a housing body and three different housing cover.

1 shows a spatial representation of a high frequency filter 1 that has a case body 2 and a housing cover 3 having. The housing body 2 includes a housing bottom 4 and one between the case back 4 and the housing cover 3 circumferential housing wall 5 , whereby the housing cover 3 from the case back 4 is spaced. In 1 was omitted for better clarity on port sockets.

The high frequency filter 1 also includes at least one coaxial resonator 6 ₁ , 6 ₂ , ..., 6 _n . Each of these coaxial resonators 6 ₁ , 6 ₂ , ..., 6 _n includes a resonator chamber 7 ₁ , 7 ₂ , ..., 7 _n . The individual resonator chambers 7 ₁ , 7 ₂ , ..., 7 _n are separated by dividers 12 or partitions 12 partially or completely separated from each other.

Each of the coaxial resonators 6 ₁ , 6 ₂ , ..., 6 _n comprises at least a first inner conductor 8th ₁ , 8th ₂ , ..., 8th _n , with the case back 4 is electrically connected and in the axial direction of the housing bottom 4 away in the direction of the housing cover 3 extends. The at least one first inner conductor 8th ₁ , 8th ₂ , ..., 8th _n ends at a distance to the housing cover 3 and / or is from the housing cover 3 galvanically isolated.

The first inner conductor 8th ₁ , 8th ₂ , ... 8th _n have in this embodiment, a receiving space 9 ₁ , 9 ₂ , ..., 9 _n , to the housing cover 3 is open and the first inner conductor 8th ₁ , 8th ₂ , ..., 8th _n at least partially interspersed in the axial direction.

The housing cover 3 includes at least a second inner conductor 10 that with the housing cover 3 is electrically connected and in the axial direction of the housing cover 3 in the direction of the housing bottom 4 extends. The at least one second inner conductor 10 ends at a distance from the caseback 4 and / or is from the housing bottom 4 galvanically isolated. In the embodiment of 1 extends the second inner conductor 10 in the receiving opening 9 ₁ , 9 ₂ , ..., 9 _{n of} the first inner conductor 8th ₁ , 8th ₂ , ..., 8th _n inside. The second inner conductor 10 However, here is the first inner conductor 8th ₁ , 8th ₂ , ..., 8th _n galvanically isolated. The second inner conductor 10 could also be quite common next to the first inner conductor 8th ₁ , 8th ₂ , ..., 8th _n in the resonator chamber 7 ₁ , 7 ₂ , ..., 7 _n end.

The individual coaxial resonators 6 ₁ , 6 ₂ , ..., 6 _n are only partially coupled with each other. A coupling mainly occurs between the adjacent coaxial resonators 6 ₁ , 6 ₂ , ..., 6 _n instead. The height of the coupling can be through openings 11 in the divider 12 , as well as, for example via electrically conductive elements, which from the housing bottom 4 and the dividers 12 are electrically isolated (not shown), are affected.

In addition to dividers 12 There are also so-called coupling webs, which in 1 are not shown. These extend from the housing bottom 4 partly in the direction of the housing cover 3 and connect two inner conductors 8th ₁ , 8th ₂ , ..., 8th _n galvanic with each other. This is a predominantly inductive coupling, because these coupling webs, the first inner conductor 8th ₁ , 8th ₂ , ..., 8th _n near the housing 4 connect with each other.

The high frequency filter 1 , in particular the housing body 2 , is preferably made of aluminum or brass or another metal. The metal is, for example, galvanized with silver. Of the housing body 2 is preferably produced in a casting process. In this case, liquid metal is pressed under pressure into a casting mold. The high frequency filter 1 should also be used for high frequencies (> 1 GHz). Therefore, even the smallest deviations of the actual shape from the desired shape lead to the high-frequency filter 1 is disgruntled and must be reconciled later. Such a vote succeeds in particular in that tuning elements different distances in the individual resonator 7 ₁ , 7 ₂ , ..., 7 _{n be} introduced. As will be explained later, with the inventive selection of housing body 2 and housing cover 3 be partially dispensed with these tuning elements.

2 shows the optimal course of a frequency-dependent transmission curve 17 (Frequency-dependent reference transmission curve) of a high-frequency filter and deviations 17 ' . 17 '' of which, arising from the fact that the housing body 2 and the housing cover 3 Have manufacturing tolerances and are not matched. The high frequency filter 1 has a restricted area 15 , which extends here in the frequency range from 1.92 GHz to 1.98 GHz. In this frequency range must be the high frequency filter 1 have an attenuation greater than 60 dB. The high frequency filter 1 also includes a pass band 16 , which lies in the frequency range from 2.11 GHz to 2.17 GHz. In this passband 16 should the high frequency filter 1 have the lowest possible attenuation. Of course it is also possible that the high frequency filter 1 used in other frequency ranges.

Due to manufacturing tolerances, there are deviations from an ideal high frequency filter 1 , The frequency-dependent reference transmission curve 17 an ideal high frequency filter 1 is described by the solid curve. Spotted and dashed are possible gradients of the frequency-dependent transmission curve 17 ' . 17 '' , These reflect the preferred maximum deviations from the reference transmission curve 17 again. For the frequency-dependent (reference) transmission curves 17 . 17 ' . 17 '' In this embodiment, this is the forward transmission factor S _{21 of} the high-frequency filter 1 , These deviations are problematic, especially in the passband 16 , Here, higher attenuations can cause the manufactured high-frequency filter 1 does not work according to its specifications.

This problem can also be in the restricted area 15 occur. The 3A and 3B show here an enlarged view 2 , 3A shows an enlarged view of the passband 16 , whereas 3B an enlarged view of the blocking area 15 shows. In the manufacturing process, high frequency filters 1 whose frequency-dependent transmission curve is either the frequency-dependent reference transmission curve 17 corresponds or deviates from this course and the dotted or dashed gradients 17 ' . 17 '' out 3A accepts. These courses 17 ' . 17 '' should be avoided, however. In the present invention, therefore, possibilities are shown with which the dotted or dashed curve of the frequency-dependent transmission curve 17 ' . 17 '' the solid curve of the frequency-dependent reference transmission curve 17 can be adjusted.

This adaptation is carried out according to the invention less by screwing tuning elements in the resonator 7 ₁ , 7 ₂ , ..., 7 _n , but rather in that individual housing body 2 with optimal housing covers 3 be united from a group of housing covers. In the invention, therefore, ways are shown to matching pairs consisting of housing body 2 and housing cover 3 find.

In some filter types, the fact is exploited that the geometric shape, in particular the second inner conductor 10 of the housing cover 3 , much stronger from the geometric shape of a reference housing cover 3 must differ than that in the case body 2 the case is to achieve the same detuning. This means that with standard manufacturing processes targeted housing cover 3 can be manufactured by a certain factor of an ideal housing cover 3 as he would for an ideal case body 2 would be used differ. This housing cover 3 can be made more reproducible with respect to their deviations. There is therefore a group of housing covers 3 , in particular with regard to their second inner conductor 10 differ from each other. Under a second inner conductor 10 are preferably all structures to understand, starting from a bottom 19 of the housing cover 3 at least partially into the resonator chamber 7 ₁ , 7 ₂ , ..., 7 _{n reach into it} . It is also possible to use structures which are arranged between the resonators.

To determine which housing cover 3 on which housing body 2 must be placed, the deviation of the housing body 2 be determined by a reference housing body.

4A suggests for this purpose at least one electrical property of the housing body 2 to measure it from a reading for this property of the housing body 2 to investigate. This electrical property is preferably around an S-parameter. The electrical property is preferably determined by a test cover 20 on the housing body 2 placed on and optionally pressed to this. Because of the test cover 20 on the housing body 2 is pressed, can be dispensed with a screw connection. The test cover 20 does not have to be with the case body 2 be screwed. It is preferably always the same test cover 20 used the different case body 2 regarding their electrical properties. The test cover 20 has at least one first capacitive coupling rod 21 on. This is galvanic from the test cover 20 separated. The at least one first capacitive coupling rod 21 becomes adjacent to the at least one first inner conductor 8th ₁ in the resonator chamber 7 _{1 of} the at least one coaxial resonator 6 ₁ introduced. The closer the capacitive coupling rod 21 to the at least one first inner conductor 8th ₁ , the more accurate and sensitive the measurement becomes.

In 4A has the test cover 20 a second capacitive coupling rod 22 on. This is also galvanic from the test cover 20 separated. The second capacitive coupling rod 22 is also spatially and galvanically from the first capacitive coupling rod 21 separated. The second capacitive coupling rod 22 can be in the same resonator chamber 7 ₁ , 7 ₂ , ..., 7 _n are already introduced in the already the first capacitive coupling rod 21 is introduced. Preferably, however, the second capacitive coupling rod is introduced into another resonator chamber. The first and the second coupling rod 21 . 22 Therefore, they are preferably in different resonator chambers 7 ₁ , 7 ₂ , ..., 7 _n .

In the event that the first and the second capacitive coupling rod 21 . 22 in different resonator chambers 7 ₁ , 7 ₂ , ..., 7 _n can be used, these resonator chambers 7 ₁ , 7 ₂ , ..., 7 _n adjacent to each other. Of course, it can also be that the two resonator chambers 7 ₁ , 7 ₂ , ..., 7 _n still by at least one other resonator 7 ₁ , 7 ₂ , ..., 7 _n are separated from each other.

In another embodiment, the first capacitive coupling bar 21 into the resonator chamber 7 ₁ introduced at the beginning of a filter path of the housing body 2 is arranged. In contrast, the second capacitive coupling bar 22 into the resonator chamber 7 _n introduced at the end of the filter path. In other embodiments, however, this can also be different.

So it would also be possible for the test cover 20 preferably so many capacitive coupling rods 21 . 22 has, as it coaxial resonators 6 ₁ , 6 ₂ , ..., 6 _n , where at least one capacitive coupling bar 21 . 22 in each of the coaxial resonators 6 ₁ , 6 ₂ , ..., 6 _{n is} introduced.

The capacitive coupling rods 21 . 22 are each with one input of a network analyzer 23 , in particular a vectorial network analyzer 23 connected. The network analyzer 23 then determines the at least one S parameter. Preferably, the forward or reverse transmission factor becomes between two resonator chambers 7 ₁ , 7 ₂ , ..., 7 _n determined.

In 4A becomes the at least one capacitive coupling rod 21 through an opening 24 in the test lid 20 into the resonator chamber 7 _{1 of} the at least one coaxial resonator 6 ₁ introduced. The same applies to the second capacitive coupling rod 22 , This is also through an opening 24 in the test lid 20 into the further resonator chamber 7 _{2 of} the at least one further coaxial resonator 6 ₂ introduced. However, it is also possible that on such an opening 24 is waived. The capacitive coupling rods 21 . 22 then would from an inner surface 19 the test cover 20 in the direction of the respective resonator chamber 7 ₁ , 7 ₂ , ..., 7 _n stand out. Only the measuring cables would have to pass through an opening in the test cover 20 or in the housing body 2 to the network analyzer 23 be guided.

When using a test cover 20 should be the individual capacitive coupling rods 21 . 22 preferably do not move against each other, especially when measuring different housing bodies 2 , The capacitive coupling rods 21 . 22 should be used when measuring different housing bodies 2 in each case at the same place and equally far into the respective resonator chamber 7 ₁ , 7 ₂ , ..., 7 _{n be} introduced.

In 4B and 4C further possibilities are shown with which it can be determined how large the deviation of a housing body 2 from a reference housing body. In 4B becomes a geometric property of the case body 2 determined. This geometric property is the height of a coupling web. In 4C the geometric property is the diameter and / or the height of at least one first inner conductor 8th ₁ , 8th ₂ , ..., 8th _n . The geometric properties are determined here with mechanical tools. However, they could also be determined without contact, for example by means of a laser.

As will be explained later, based on the measured values, the at least one property of the housing body 2 describe how large the measured value deviations between the housing body 2 and a reference housing body. Based on the height of the measured value deviation the measured values of a reference value, these measured value deviations can be selected by selecting a suitable housing cover 3 from a group of at least two housing covers 3 , preferably different second inner conductors 10 have, be reduced, or even compensated. This means that when combining the case body 2 with the selected housing cover 3 a frequency-dependent transmission curve of the high-frequency filter formed therefrom 1 a frequency-dependent reference transmission curve 17 closer or closest comes. The frequency-dependent reference transmission curve 17 was in 2 shown.

In 5 a flow chart is shown, which explains how the selection of housing body 2 and matching housing cover 3 he follows. The flowchart then applies when using the in 4A measuring method shown an electrical property of the housing body 2 is determined. In a first method step S ₁ is on the housing body to be measured 2 a test lid 20 placed. The test cover 20 is preferably on the housing body 2 pressed. The test cover 20 comprises at least one capacitive coupling rod 21 . 22 ,

Subsequently, the method step S _{2 is} carried out. In the method step S ₂ , the electrical property of the housing body 2 measured. This is at least an S parameter in this case. Preferably, it is the forward or reverse transmission factor. This S parameter is the frequency-dependent transmission curve.

Following this, method step S _{3 is} carried out. In method step S ₃ , only certain frequency ranges of the at least one S parameter are examined. There is a so-called feature extraction or feature reduction. In this case, the at least one measured value is extracted from the S parameters. The at least one measured value correlates, for example, to the bandwidth or to the center frequency of the S parameter in the passband 16 and / or in the restricted area 15 , The at least one measured value is therefore preferably in the frequency range of the passband 16 and / or the blocking area 15 the high frequency filter 1 , It can also be at the upper or lower limit frequency of the passband 16 or the blocking area 15 correlate. The at least one measured value is preferably the frequency-dependent transmission curve or a part thereof. The frequency-dependent transmission curve is preferably to be understood as the course of the forward or backward transmission factor. Of course, this frequency-dependent transmission curve deviates from a frequency-dependent reference transmission curve 17 . 18 because of the test cover 20 not with a proper housing cover 3 can be compared.

The frequency-dependent reference transmission curve 17 . 18 can be obtained by providing a reference housing body with a reference cover. Such a reference transmission curve 17 would be in 6 to see. However, it can also be obtained by having a reference housing body with the test cover 20 is provided. Such a reference transmission curve 18 would be in 7 to see. These reference transmission curves 17 . 18 then represent a reference value, with which the at least one measured value is compared or from these reference transmission curves 17 . 18 a reference value is generated with which the at least one measured value is compared. If the at least one measured value correlates, for example, with the center frequency, then the reference value represents the center frequency. Both values therefore describe the same physical quantity.

The method step S ₃ is to be regarded as optional. It is also possible to process the entire frequency-dependent transmission curve.

Subsequently, method step S _{4 is} carried out. In method step S ₄ , it is determined how large a measured value deviation of the at least one measured value for the measured characteristic of the housing body 2 from a reference value of a reference case body. For example, it can be checked whether the at least one measured value, for example, with the center frequency in the passband 16 for the housing body to be checked 2 correlates approximately with the center frequency, as in the passband 16 a reference housing body is present.

Subsequently, the method step S _{5 is} carried out. In method step S ₅ , a corresponding housing cover 3 from a group of at least two housing covers 3 selected or used. The selection is made according to how large the measured value deviations of the measured value are. In the event that the at least one measured value to the center frequency of the housing body to be measured 2 correlated, is below a center frequency of a reference housing body, a housing cover must 3 be selected, the second inner conductor 10 shorter than the second inner conductor 10 a housing cover 3 which would be connected to the reference housing body. In contrast, in the event that the at least one measured value, which is at the center frequency of the housing body to be measured 2 correlated, is above a center frequency of the reference housing body, a housing cover 3 be selected, the second inner conductor 10 is longer than the second inner conductor 10 a housing cover 3 which would be connected to the reference housing body. This allows tolerances in the manufacturing process of the housing body 2 be compensated.

• a) der Gehäusekörper 2, für den der Messwert größer ist als der Referenzwert, wird mit einem Gehäusedeckel 3 zusammengefügt, der einen größeren und/oder längeren und/oder dickeren zweiten Innenleiter 10 aufweist als der Gehäusedeckel 3, der mit einem Gehäusekörper 2 zusammengefügt werden würde, dessen Messwert dem Referenzwert entspricht; oder
• b) der Gehäusekörper 2, für den der Messwert kleiner ist als der Referenzwert, wird mit einem Gehäusedeckel 3 zusammengefügt, der einen kleineren und/oder kürzeren und/oder dünneren zweiten Innenleiter 10 aufweist als der Gehäusedeckel 3, der mit einem Gehäusekörper 2 zusammengefügt werden würde, dessen Messwert dem Referenzwert entspricht.

If the measured value to the bandwidth and / or the center frequency and / or the lower or upper limit frequency of the housing body 2 correlated there are different ways, such as the housing cover 3 for the housing body to be examined 2 is selected:

• a) the housing body 2 , for which the measured value is greater than the reference value, comes with a housing cover 3 joined, the one larger and / or longer and / or thicker second inner conductor 10 has as the housing cover 3 that with a housing body 2 would be joined, whose measured value corresponds to the reference value; or
• b) the housing body 2 , for which the measured value is smaller than the reference value, comes with a housing cover 3 joined, the one smaller and / or shorter and / or thinner second inner conductor 10 has as the housing cover 3 that with a housing body 2 would be joined together whose measured value corresponds to the reference value.

On the basis of the amount of deviation of the at least one measured value from the reference value, a housing cover 3 be selected, the second inner conductor 10 by a predetermined length and / or width (ie shape) of the second inner conductor 10 of a reference housing cover deviates. If such a condition of the second inner conductor 10 with the available housing covers 3 does not exist, then the housing cover 3 selected, the second inner conductor 10 the closest to the desired length and / or width (ie shape) come closest.

6 shows two different frequency-dependent transmission curves 17 . 18 a high frequency filter 1 , where the high frequency filter 1 once with a normal housing cover 3 and once with a test cover 20 is closed. Dashed lines show the frequency-dependent reference transmission curve 17 , This curve is achieved when a reference housing body with a matching housing cover 3 is completed. With a solid line is a frequency-dependent transmission curve 18 shown in measuring the forward transmission factor of the housing body 2 with the test cover 20 results. The characteristic of this frequency-dependent transmission curve correlates only loosely with that of the reference transmission curve, which is due to the fact that the combination of housing body 2 , Test cover 20 and coupling rods 21 . 22 does not yield a complete high frequency filter. The frequency-dependent transmission curve 18 However, information about the achievable bandwidth and the center frequency. The achievable bandwidth must correspond to a predetermined reference value. The center frequency must correspond to a previously set reference value. Deviations from this can be achieved by selecting a suitable housing cover 3 be compensated.

7 shows the optimal course of a frequency-dependent reference transmission curve 18 a high frequency filter 1 that with a test lid 20 is closed and (measured) deviations thereof, which arise because of the housing body 2 Having manufacturing tolerances. Depending on how strong the case body 2 is deviated from a reference housing body when placing the test cover 20 the dotted or dashed curve of the frequency-dependent transmission curve 18 ' . 18 '' measured. This deviates from the ideal course 18 which is in 7 marked with a solid line, from. This measurement deviation, which in 8th shown enlarged, can by selecting a suitable housing cover 3 be compensated. The at least one measured value is compared with a reference value. The reference value results from the course of the curve 18 with the solid line.

9 shows the housing body 2 and a group of housing covers 3 , The group consists in this embodiment of three different housing covers 3 , These differ in the length of their second inner conductor 10 , Depending on how strong the measured frequency-dependent transmission curve or parts of the frequency-dependent transmission curve are from a frequency-dependent reference transmission curve 17 . 18 will deviate from one of the three housing covers listed above 3 with the housing body 2 connected.

The selection of the appropriate housing cover 3 from a group of at least two housing covers 3 with different second inner conductors 10 takes place such that a difference between a frequency-dependent transmission curve of the housing body 2 and the housing cover 3 formed high-frequency filter 1 and a frequency-dependent reference transmission curve 17 . 18 is smaller than a predefinable deviation value.

The invention is not limited to the described embodiments. Other measuring methods for the electrical and / or geometric properties of the housing body 2 are also possible. In the context of the invention, all described and / or drawn features can be combined with each other as desired.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010056048 A1 [0006, 0007]

Claims (12)

Method for assembling high-frequency filters ( 1 ), each high-frequency filter ( 1 ) has a high-frequency housing which has a housing body ( 2 ) and one on the respective housing body ( 2 ) matched housing cover ( 3 ): - the housing body ( 2 ) comprises a housing bottom ( 4 ) and one between the housing bottom ( 4 ) and the housing cover ( 3 ) circumferential housing wall ( 5 ), whereby the housing cover ( 3 ) from the housing bottom ( 4 ) of the housing body ( 2 ) is spaced; - the high-frequency filter ( 1 ) comprises at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) having a resonator chamber ( 7 ₁ , 7 ₂ , ..., 7 _n ); - the at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) comprises at least a first inner conductor ( 8th ₁ , 8th ₂ , ..., 8th _n ) in the resonator chamber ( 7 ₁ , 7 ₂ , ..., 7 _n ), wherein the at least one first inner conductor ( 8th ₁ , 8th ₂ , ..., 8th _n ) with the housing bottom ( 4 ) is electrically connected and in the axial direction of the housing bottom ( 4 ) in the direction of the housing cover ( 3 ) extends; The at least one first inner conductor ( 8th ₁ , 8th ₂ , 8th _n ) ends at a distance in front of the housing cover ( 3 ) and / or is from the housing cover ( 3 ) galvanically isolated; - the housing cover ( 3 ) comprises at least a second inner conductor ( 10 ), which with the housing cover ( 3 ) is electrically connected and in the axial direction of the housing cover ( 3 ) in the direction of the housing bottom ( 4 ) extends; The at least one second inner conductor ( 10 ) ends at a distance from the housing bottom ( 4 ) and / or is from the housing bottom ( 4 ) galvanically isolated; wherein for finding a matching pair consisting of housing body ( 2 ) and housing cover ( 3 ) the following method steps are carried out: measuring (S ₂ ) at least one electrical and / or geometric property of the housing body ( 2 ) and determining at least one measured value for this property of the housing body ( 2 ); Determining (S ₄ ) how large a measured value deviation of the measured value from a reference value for this property of the housing body ( 2 ); Use (S ₅ ) a corresponding housing cover ( 3 ) depending on the height of the measured value deviation from a group of at least two housing covers ( 3 ) with different second inner conductors ( 10 ) such that, in order to reduce the measured value deviation, the signal from the housing body ( 2 ) with the housing cover used ( 3 ) formed high-frequency filter ( 1 ) has a frequency-dependent transmission curve corresponding to a frequency-dependent reference transmission curve ( 17 . 18 ) closer or closest. Method for assembling high-frequency filters according to Claim 1, characterized by the following feature: - that in the method step using (S ₅ ) the housing cover ( 3 ) is selected so that the frequency-dependent transmission curve of the high-frequency filter formed of the frequency-dependent reference transmission curve ( 17 . 18 ) at least in the passband ( 16 ) and / or in the restricted area ( 15 ) closer or closest. Method for assembling high-frequency filters according to Claim 1 or 2, characterized by the following features: - in the case of the geometric property of the housing body ( 2 ) is the diameter and / or the height of the at least one first inner conductor ( 8th ₁ , 8th ₂ , ..., 8th _n ); and / or - in the case of the geometric property of the housing body ( 2 ) is the height of at least one coupling web and / or separating web ( 12 ) extending from the caseback ( 4 ) and two first inner conductors ( 8th ₁ , 8th ₂ , ..., 8th _n ) of two coaxial resonators ( 6 ₁ , 6 ₂ , ..., 6 _n ) connects to each other or separates from each other or is located between two coaxial resonators; and / or - in the electrical property of the housing body ( 2 ) is at least one S-parameter. Method for assembling high-frequency filters according to Claim 3, characterized by the following features: the measured value describes a geometric property of the housing body ( 2 ) and: a) the housing body ( 2 ), for which the measured value is smaller than the reference value, is provided with a housing cover ( 3 ), which has a larger and / or longer and / or thicker second inner conductor ( 10 ) than the housing cover ( 3 ), which is connected to a housing body ( 2 ) whose measured value corresponds to the reference value; or b) the housing body ( 2 ) for which the measured value is greater than the reference value, is provided with a housing cover ( 3 ), which has a smaller and / or shorter and / or thinner second inner conductor ( 10 ) than the housing cover ( 3 ), which is connected to a housing body ( 2 ) whose measured value corresponds to the reference value. Method for assembling high-frequency filters according to Claim 3, characterized in that the following method step is carried out in the method step measuring (S ₂ ): measuring at least one S parameter; the at least one measured value is obtained in the step Extract (S ₃ ) from the at least one S parameter and: a) lies in the frequency range of the passband ( 16 ) and / or the blocking area ( 15 ) of the high-frequency filter ( 1 ); and / or b) correlates to the bandwidth of the passband ( 16 ) and / or the blocking area ( 15 ); and / or c) correlates to the center frequency of the passband ( 16 ) and / or the blocking area ( 15 ); and / or d) correlates to the upper and / or lower limit frequency of the passband ( 16 ) and / or the blocking area ( 15 ). Method for assembling high-frequency filters according to one of the preceding claims, characterized in that before the method step measuring (S ₂ ) the following method steps are carried out: - placing (S ₁ ) a test cover ( 20 ) on the housing body ( 2 ) of the high-frequency housing; - pressing the test cover ( 20 ) on the housing body ( 2 ) of the high-frequency housing. Method for assembling high-frequency filters according to Claim 6, characterized by the following feature: - the test cover ( 20 ) has at least one first capacitive coupling rod ( 21 ), which is galvanically isolated from the test cover ( 20 ) is separated and adjacent to the at least one first inner conductor ( 8th ₁ , 8th ₂ , ..., 8th _n ) into the resonator chamber ( 7 ₁ , 7 ₂ , ..., 7 _n ) of the at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) is introduced. Method for assembling high-frequency filters according to Claim 7, characterized by the following features: - the test cover ( 20 ) has at least one second capacitive coupling rod ( 22 ) on; the second capacitive coupling rod ( 22 ) is galvanically isolated from the test cover ( 20 ) separated; the second capacitive coupling rod ( 22 ) is spatially and galvanically from the first capacitive coupling rod ( 21 ) separated; The second capacitive coupling rod ( 22 ) is adjacent to: a) to the at least one first inner conductor ( 8th ₁ , 8th ₂ , ..., 8th _n ) into the resonator chamber ( 7 ₁ , 7 ₂ , ..., 7 _n ) of the at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) introduced; or b) to a further first inner conductor ( 8th ₁ , 8th ₂ , ..., 8th _n ) into the resonator chamber ( 7 ₁ , 7 ₂ , ..., 7 _n ) of another coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ). Method for assembling high-frequency filters according to Claim 8, characterized by the following features: - the at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) into which the first capacitive coupling rod ( 21 ) and the further coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) into which the at least one second capacitive coupling rod ( 22 ) are arranged adjacent to each other; or the at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) into which the first capacitive coupling rod ( 21 ) and the further coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) into which the at least one second capacitive coupling rod ( 22 ) are introduced by at least one further coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) are separated from each other; and / or - the at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) into which the first capacitive coupling rod ( 21 ) is at the beginning of a filter path of the housing body ( 2 ) and the further coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) into which the at least one second capacitive coupling rod ( 22 ) is placed at the end of the filter path. Method for assembling high-frequency filters according to Claim 8 or 9, characterized by the following feature: - the test cover ( 20 ) has at least as many capacitive coupling rods ( 21 . 22 ) on how it coaxial resonators ( 6 ₁ , 6 ₂ , ..., 6 _n ), wherein at least one capacitive coupling rod ( 21 . 22 ) in each of the coaxial resonators ( 6 ₁ , 6 ₂ , ..., 6 _n ) is introduced. Method for assembling high-frequency filters according to one of Claims 6 to 10, characterized by the following feature: - the at least one first capacitive coupling rod ( 21 ) is passed through an opening ( 24 ) in the test lid ( 20 ) in the resonator chamber ( 7 ₁ , 7 ₂ , ..., 7 _n ) of the at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) introduced; and / or - the at least one first capacitive coupling rod ( 21 ) is at a predetermined distance from an inner surface ( 19 ) of the test cover ( 20 ) in the direction of the resonator chamber ( 7 ₁ , 7 ₂ , ..., 7 _n ) of the at least one coaxial resonator ( 6 ₁ , 6 ₂ , ..., 6 _n ) down. A high-frequency filter produced according to one of the preceding claims, wherein the high-frequency filter ( 1 ) a housing body ( 2 ) and one on the housing body ( 2 ) matched housing cover ( 3 ) having.

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