EP3143664A1

EP3143664A1 - Mobile radio antenna

Info

Publication number: EP3143664A1
Application number: EP15724939.2A
Authority: EP
Inventors: Dan Fleancu; Manfred Stolle
Original assignee: Kathrein Werke KG
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2014-05-15
Filing date: 2015-05-07
Publication date: 2017-03-22
Also published as: CN106463819B; US10186748B2; DE102014007141A1; US20170077587A1; WO2015172871A1; CN106463819A

Abstract

An improved mobile radio antenna that is suited to radio-frequency connections is distinguished inter alia by the following features: having a base module (1) that comprises a plurality of mounting sections (1a) that each contain an internally threaded hole (15'), having an attachment module (3) that has mounting sections (3a) with through-holes (17) made therein, having spacers (21) between the base module (1) and the attachment module (3), wherein the undercut (31, 131) a) is provided in the through-hole (17) in the attachment module (3) such that the diameter of the through-hole (17) merges into the undercut (31) with a greater diameter in the plug-in direction (20), or b) is provided in a second electrically conductive spacer (121) that is positioned on the attachment module (3) on the side that is opposite the first spacer (21), the second spacer (121) having a spacer hole (11) with an undercut (131) that broadens in the plug-in direction.

Description

Mobi1funkantenne

The invention relates to a mobile radio antenna according to the preamble of claim 1. In radio frequency engineering in general and in the field of Mobi1funkantennen technology in particular, often screwed connections are used, for example, to attach a metal lid to a metal housing, to attach dipole spotlights on reflectors, etc ..

According to today's standard reflectors are used, for example, in the mobile radio technology, which are designed similar to the housing on its back side to the radiator side, in this space, for example, the wiring, phase shifters, adjusting devices for the phase shifter, filter assemblies, etc. can be accommodated. In this case, the reflector can be provided with side wall webs, which are connected in fastening flanges ending parallel to the reflector plane. hen, where then, for example, a reflector cover can be screwed.

In addition, with today's packaging density of corresponding mobile radio antennas, active assemblies housed in separate housings, such as a radio (RRH), on the back of the reflector, often also become obstructive. in the case described, for example, on the above mentioned reflector cover covering the back of the reflector.

Therefore, it is always necessary that the corresponding parts are fixed to each other with a plurality of screws.

According to a known standard, for example, on the back of the reflector on the mentioned fastening flanges a multiplicity of spaced press nuts on drill holes in the reflector mounting flange can be pressed correspondingly to provide a prefix for further assembly. On the fastening flange then a lid can be placed, in which holes are also introduced. These holes are aligned with the holes in the mentioned press nuts. Internal threads are formed in the press-in nuts themselves so that corresponding screws for fixing the cover can be screwed in from the opposite side. If, however, the housing of another component is also mounted on the cover, as mentioned above, further bores are also introduced in this housing, as a rule, on laterally projecting flange sections aligned with the other holes to then screw from the back of the component to be mounted screws through the aligned holes to the mentioned internal thread of the press-in nuts.

In addition, variants are also known in which, for example, a reflector is formed as an extruded part. On the corresponding mounting or fastening flange, the reflector may be formed with a thicker material thickness, which makes it possible to introduce an internally threaded bore or an internally threaded blind bore from the mounting side. In this case, so can be dispensed with the mentioned Einpressmuttern. Nevertheless Einpressbuchsen be used in this case, which is prefixed with the attached to the reflector lid by pressing. Because this makes it possible to pre-fix the parts so that they can be placed on each other and then screwed in a variety of corresponding drill joints. Often far more than 30 or 40 screws must be screwed into the corresponding internal threaded holes.

In all these cases, however, it has been found that, especially due to the pressing of the mentioned press-fit nuts or by the pressing of the mentioned press-fit bushings, at least minimal skewing can occur, with the result that no clearly reproduced contact points between the reflector, the Deflection and / or the housing eg an active component are given. However, not clearly reproducible contact points always lead to changed conditions, whereby, in particular in high-frequency engineering, desired intermodulations may arise.

The above-mentioned unacceptable tolerance deviations can occur both in the vertical direction and in the horizontal direction with respect to the components which are to be fixed to one another more flatly. These tolerance deviations are generally unacceptable or bridgeable.

In the past, attempts have already been made to form contact protrusions or contact recesses projecting from the normal fastening plane in each case at the corresponding mounting sections at which the parts to be fixed contact one another directly. But even by these embossing operations minimum tolerance errors can arise, which always lead to different conditions. The same applies to appropriately projecting and usually annular contact sections, which have often been formed in previous housings of active structural components, filter groups, etc., in the hope of achieving improved contact conditions here. Finally, when joining and screwing the individual subassemblies, surface injuries to the electrically conductive layers or to the metal can also occur, which likewise lead to changed contact conditions. In all these cases, only a very poor control of the surface pressure due to unequal surface sizes (diameter of the contact sections) is given by the production. As has been shown in the context of the invention, all the experiments that have become known so far are characterized by a contact geometry that does not meet the needs of intermodulation problems. In addition, additional intermodulation-impairing conditions may also arise due to mismatched material pairing, ie when parts come into contact with one another, which consist of different materials or have different surface coatings.

Therefore, sometimes considerable attempts are made to avoid possible tolerance-related deviations in the manufacture and assembly of such components. However, the smaller tolerance deviations should be, the greater the effort required for this purpose.

It is therefore an object of the present invention to provide a screw connection which is suitable for high-frequency technology and which makes it possible to reduce or even avoid intermodulation products.

The object is achieved according to the invention in accordance with the features specified in claim 1. Advantageous embodiments of the invention are specified in the subclaims.

The solution according to the invention relates to a mobile radio antenna in which a base module with an add-on module is firmly connected using a spacer by means of a plurality of screw connections. In principle, the solution according to the invention can also be used for different The most helical screw and support connections are used, but especially in the field of high-frequency technology, such as the mobile radio technology, ie in particular in the field of antenna mounting for mobile phone base stations.

In this case, it is provided in a base configuration of the mobile radio antennas that a spacer, for example a sleeve-shaped spacer, is provided between two components to be fastened to one another, which are usually made of metal or coated with a metallic coating.

In order to close a reflector in the antenna technology on the rear side at a distance from the actual reflector plane with a lid, for example in the form of a metal plate, a plurality of holes are usually provided on two opposite longitudinal sides in a part of the reflector forming flange, For example, to attach the lid to the reflector using 40 or more screws. In order to be able to carry out a practicable assembly, it is necessary to prefix the mentioned preferably bush-shaped spacers in the area of the boreholes in the mentioned cover. By prefixing it is then possible to easily hang the cover on the back of the reflector with the spacers and to fix it at the mounting points formed there by screwing in screws. The pre-fixed standoffers are held captive in their correct position. This prefixing has been realized in the prior art by inserting corresponding bushing spacers, which has contributed to an additional deterioration of the overall situation, as due to the high pressing forces the mounting areas and sections of the parts to be joined together in addition to a deformation, embossing, the incorporation of indentations etc., whereby the unwanted Intermodulation- tion products could occur more or more.

In the context of the invention it is now provided that the prefixing of the mentioned preferably sleeve-shaped spacers is made without generating high press-in forces, i. only be prefixed by inserting.

In this case, the spacers which are thus prefixed in a fixed manner can be prefixed with a small clearance, which is preferably effective both in the axial direction and in the transverse direction, for example in two transverse directions provided perpendicular to the axial direction. It may be sufficient that this game is only a fraction of a millimeter. This preferred low game offers the further advantage in the final assembly, that any tolerance deviations can be per ^¬ without difficulty balanced characterized because the distance ^¬ holder can automatically assume the optimum position during screwing, so that the successive placed and by screws for connecting parts as possible plane-parallel and flat with sandwich-like recording of the mentioned spacer can be connected to each other. This will be the state of the art always occurring and unwanted intermodulation avoided or at least greatly reduced.

According to the invention, provision is made for the spacers to have a plug-in section which projects into the passage bore of an add-on module (such as, for example, a cover to be screwed to a reflector). There, the plug-in section has a holding section, which is preferably attached in the plug-in direction and protrudes in the radial direction, which engages on an undercut formed in the through-hole in the plug-in direction. As a result, the spacer is optionally prefixed with at least a small clearance and thus held captive.

It is likewise possible for the radially projecting holding section to project through the fastening bore on the insertion section of the spacer and to protrude in the insertion direction on the opposite side of the add-on module, where, however, then in a second spacer bushing positioned on this side of the add-on module in a corresponding bore engages and ends in the area of an undercut formed there in the borehole. Thus, the spacer quasi consists of a combination spacer with two spacer halves, which come to lie above and below the to be fixed and preferably plate-shaped add-on module (for example in the form of a reflector cover). By the aforementioned prefix under sandwich-like recording of the mounting module to be fixed, the two halves of the combination spacer to each other and thus prefixed to the add-on module and held captive. For screwing the entire arrangement with the add-on module, for example in the form of the reflector cover and the sole spacer socket or the two so-called combination jack forming spacer jacks placed on the corresponding mounting surfaces of a base module, for example in the form of mounting flanges on the back of a reflector are then to insert from the side opposite the base module side of a plurality of screws through the holes in the mounting module and the spacer bushes and screw in the provided internal thread in the base module.

In addition, additional components or components to be fixed may be included on the upper side of the second half of the combination spacer or directly on the upper side of the add-on module (if only a simple spacer is used between the mounting module and the base module). Modules are called. In the case of mobile radio antennas for base stations, these component modules can, for example, consist of so-called remote radio heads (RRH), which are accommodated in a separate component housing which has corresponding carrier flanges, into which the corresponding holes are likewise taken how the holes are made in the mounting and base module.

Therefore, the present invention is as described for mobile antennas, but in principle can also be generally used in high-frequency engineering in connection with screw in which, for example, a base or reflector module to be firmly connected at least with a mounting module. In addition, additional cultivation modules can be mitfixiert.

Thus, within the scope of the invention multiple position tolerance deviations in both the axial direction and in the transverse direction can be bridged. As described in the prior art, no more parts are pressed, which lead to a worsening of the assembly conditions and, above all, of the contact conditions. Since no press-fit parts have to be pressed with high forces on boreholes, none of these points are formed Injury to the metal surfaces, causing the formation or enhancement of intermodulation.

Finally, in the context of the invention, a better control of the surface pressure by an equal area size of the superimposed parts (diameter) can be achieved.

Overall, this results in an intermodulation-compatible contact geometry and, above all, an intermodulation-compatible material pairing. In particular, when not only two modules, but three modules are to be screwed together, for example in the form of a reflector for holding a plurality of radiators and radiator elements, and a reflector cover and another component, for example in the form of a radio, there are further advantages. By using a so-called combi spacer, ie, for example in the form of a second spacer sleeve next to a first spacer sleeve, here by appropriate dimensioning of these spacer sleeves in the axial direction almost any desired and perceived as optimal axial distance, for example, between the lid and the bottom the housing of the radio above it. In addition, the individual components and modules can optionally consist of different materials or be provided with different electrically conductive and / or metallic coatings. The same applies to the mentioned spacers. In the case of combi spacers, both parts of this combi spacer may also be made of different metals or coated with different metals or alloys. Thus, for example, one half of the spacer can be silvered and the second half cooperating therewith and fixed thereto can be galvanized. Further different metal pairings are possible.

The embodiment according to the invention also makes it possible for the modules to be fixed to one another not to be provided with raised contact rings or contact embossings which are above the usual contact surface and which in turn could ultimately contribute to the deterioration of the contact conditions due to the corresponding development of these protruding contact rings , Therefore, there are no further surface injuries neither when screwing the individual modules nor during the production of each other to be connected modules, because no additional protruding contact impressions must be formed.

This results in the context of the invention overall better control of the surface pressure of the juxtaposed and to be joined components and modules. In this case, the surfaces which come into contact can be produced identically for all components, as a result of which better producible electrical contact conditions are also possible while avoiding or greatly reducing intermodulation.

In principle, screw in a variety of configurations are well known.

For example, US 5 018 982 describes a screw connection with spacers and sleeve elements positioned inside the spacers, which are penetrated by a long screw connection. Between the spacers are arranged according to the height of the spacers spaced from each other in different parallel planes printed circuit boards. Therefore, the spacers and the printed circuit boards are galvanically separated from each other. This is not the problem of avoiding intermodulation products.

From DE 40 29 587 AI an arrangement by means of a screw is to be found as known, which comprises a patch on a bolt disc to implement an electrical and thermal separation between the bolts and one of the bolts enforce the housing of a water heater. Again, this does not use and solution to avoid intermodulation products.

From DE 35 02 263 A1, only one holding device is known to be able to remove printed circuit boards which are held by means of a screw connection holding the printed circuit boards at a parallel distance from one another, here likewise likewise no galvanic or other electrical connections between the spacers and the printed circuit boards. binding exists.

For this reason, even these preliminary publications are not known to contain any hints for avoiding intermodulation products in high-frequency technology.

In that regard, DE 84 22 203 U1 also describes a comparable solution with which printed circuit boards, for example printed circuit boards, are to be anchored to carrier plates in electrical appliances by means of a specific screw connection.

Finally, a fundamentally deviating connection technique can be found in US Pat. No. 8,526,195 B2. There, a conductive plate provided with a passage opening is connected to two sleeve parts, wherein a cylindrical projection of the attached on one side of the conductive plate sleeve member penetrates the bore in the conductive plate and an opening in the opposite sleeve part, up to the level of one increasingly conically widening receiving space in the opposite sleeve part. In these, the sleeve-shaped projection of the first cylinder part can be converted. be grooved so as to fix both cylinder parts on the plate. However, such connection techniques always lead to undesired intermodulation production in high-frequency technology.

The invention will be explained in more detail with reference to drawings. In detail:

Figure 1: a spatial exploded view of three components to be connected, in one

Viewing angle showing the top of a component module;

FIG. 2: a corresponding illustration to FIG. 1, but rather from the underside under the view of FIG

Underside of a base module;

Figure 3 is a fragmentary cross-sectional view transverse to the longitudinal direction of the modules shown in Figures 1 and 2 and to be connected in the assembled state;

FIG. 4: an enlarged detail of the embodiment shown in FIG

4 by a circle bounded cross-sectional area;

FIG. 5 shows a further enlarged detailed representation of the cross-sectional area bounded in FIG. 4 by a circle;

Figure 6: a corresponding cross-sectional view to

Figure 4, but in which only a mounting module and a base module using a captive pre-fixed spacer bushing according to the invention are fixed together by means of screws; FIG. 7 shows a corresponding illustration to FIG. 1 with respect to an embodiment slightly modified with respect to FIG. 1;

FIG. 8: a corresponding representation as in FIG. 2, but with respect to the slightly modified exemplary embodiment shown in FIG. 7;

FIG. 9 shows an excerpt cross-sectional view with respect to the modified exemplary embodiment;

Figure 10: an enlarged cross-sectional view of the in

Figure 9 by a circle bounded cross-sectional area;

FIG. 11 shows a further enlarged detailed representation of the cross-sectional area bounded in FIG. 10 by a circle; and FIG. 12: a corresponding cross-sectional illustration

Figure 4, in which, however, only an attachment module and a base module using a captive pre-fixed combination spacer spacer according to the invention are fixed to each other with a first and second spacers. In the exemplary embodiment shown, a base module 1, a mounting module 3 to be fastened thereto and a component module 5 are reproduced, all of which can be fastened to one another using a plurality of screws.

In the embodiment shown here consists of the base module 1 and a reflector 1, as it e.g. can be used in mobile radio antennas in a base station. In this exemplary embodiment, the add-on module 3 consists of a reflector cover 3 '. The component module 5 consists for example of an active component in the form of a radio 5 ', ie in the form of a so-called remote radio head RRH, as it can also be used within the framework of a mobile radio antenna device or system (base station) ,

The corresponding modules 1, 3, 5 usually extend over a length L, which is significantly longer than in the perspective exploded view according to FIGS. 1 or 2.

In FIGS. 1, 2 and 3, the lower side in the figures forms the front side IIa of the base module 1, here in the form of the reflector 1 '. Laid offset in the longitudinal direction L usually Dipolstrahler, Dipolquadrate, vector dipoles, Patchstrahler etc. are mounted on this front IIa, which can radiate and / or receive in one or two mutually perpendicular polarizations in one, in two or more frequency bands. In this respect, reference is made here to well-known solutions. In the embodiment shown, the base module 1 in the form of the reflector 1 'on side webs 11c projecting in the direction of the front IIa, and backward side webs lld, which in turn ends on both opposite longitudinal sides in each other to umgelängte mounting flanges llle. These mounting flanges are therefore formed on the rear side IIb of the base module 1, here in the form of the reflector 1 '. On the back of this base module 1 shown in the form of the reflector 1 'is thus a distance space 10 (Figure 3) between the surface on the back IIb of the base module 1 and the mounting flanges or the mounting module 3, here preferably in the form of Reflektorde- 3 'formed in which different components components can be accommodated. In the case of an antenna or mobile radio antenna, the cable connections leading to the radiators, in particular coaxial cables, phase shifters, linkages or other adjusting devices for adjusting or adjusting the phase shifters etc. , housed. This intended space 10 can then be covered and closed with the attachment of a reflector cover 3 ¹ , wherein the reflector cover 3 'usually has a width corresponding to the width of the underlying base module 1, here in the form of the reflector 1'. In general, therefore, an add-on module 3 is fastened and screwed onto the rear side IIb of the base module 1. It can be seen from the drawings according to FIGS. 1 to 5 that the attachment module 3, here in the form of the reflector cover 3 ', does not act directly on the base module 1, here in the form of the reflector 1', but in an intermediate Circuit of a spacer 21, here in the form of spacer bushes 21 '.

The corresponding spacer bushings 21 'are provided in each case at the points at which the attachment module, like the component module, is provided with corresponding bores.

From the embodiment shown it can be seen that the base module 1, here in the form of the reflector 1 ', on the mounting flanges shown all with a plurality of holes 15 is provided. In this case, the base module 1 is preferably formed as an extruded or continuous casting, such that the mounting flanges have a thickened material portion llf. This offers the possibility to introduce the holes 15 provided there from the rear side in the form of, for example, blind holes and to equip them with an internal thread 15 '. In that regard, it is spoken with respect to the holes 15 of internal thread holes 15, regardless of whether they are configured as a continuous holes or blind holes. In the exemplary embodiment shown, the mentioned internally threaded bores 15 are formed as through holes in the associated mounting flange 11, so that the lower end of the screws can project beyond the mounting flange 11.

With these internal threaded holes 15 are aligned holes 17 are introduced at the corresponding edge 3a of the add-on module 3, here in the form of the reflector cover 3 ', in a same distance sequence, which are referred to as through-holes. They are so dimensio- niert that the corresponding, shown in Figures 1 and 2, screws 7 with its screw shaft 7 ', on which at least a partial length an external thread is formed, can be easily pushed through.

In order to be able to carry out the installation without problems, the spacers 21, which are preferably in the form of spacer bushings 21 ', must be prefixed to the attachment module 3, i. be mounted captive at least to be able to screw together the thus prepared add-on module with the thereto, in the region of the passage bore 17 pre-fixed spacer bushings 21 'to the base module 1. In particular, it can be seen from the enlarged cross-sectional illustration according to FIGS. 4 and 5 that the spacers 21, here in the form of the spacer bushes 21 ', have an insertion projection 21a which has an outer diameter which is equal to or less than the inner diameter of the through-bore 17 in the add-on module 3.

This mentioned plug 21a has in the insertion direction 20 leading, preferably at the leading end of the plug 21, a widened in the radial direction projection 21c, which may be formed in the embodiment shown in the manner of a circumferential annular end with a larger outer diameter than the outer diameter of the plug 21a.

In this area, the attachment module 3 is spaced apart from its underside 3b with an undercut 31 extending in the direction of the upper side 3c, which in the exemplary embodiment shown is conically widened in the insertion direction. After insertion of the plug 21a of the spacer 21 in the through hole 17 of here slightly bead-shaped, radial projection 21c of the spacer holder is slightly compressed or compressed so that it can pass through the through hole 17 when plugging, until this radial projection 21c on reaching the Undercut 3d in turn can easily relax (due to the elastic deformation), and thus the radial projection 21c in the region of a larger cross section than the through hole 17 having the undercut 31 comes to lie in the add-on module 3.

The explained radial projection 21c may also be referred to as a latching ring. Insofar, the latching ring can also be provided with indentations or indentations over a partial axial length in the circumferential direction, so that the radial projection 21c is not formed as a more or less continuous latching ring, but thereby displaces a large number in the circumferential direction lying latching fingers are formed to facilitate the latching or latching in the region of the undercut. The spacer 21 is therefore formed elastically or partially elastic or at least slightly elastic at least in the region of its insertion projection 21a or at least in the region of the radial projection 21c in order to easily perform the insertion through the bore until it reaches the undercut. This also applies to the further, partly modified embodiments discussed below.

In order to form the elasticity or partial elasticity in the region of the radial projection 21c, it is provided that that the plug-in approach is increasingly thinner, especially at its leading end 21b of the material thickness. For this purpose, the plug-in projection 21a in a partial height to his leading end is preferably designed with increasingly thinner or partially thinner wall sections, including the male tab on the inside of its rather cylindrical bore 16 into a leading end 21b conically widened opening cross-section 16 'transitions. This promotes the formation of at least a certain partial elasticity for the insertion of the radially protruding latching or snap-in section 21c. This applies in the present embodiment according to Figures 1 to 5 as well as with respect to the following embodiments.

As a result, the mentioned spacer 21 in the form of the spacer bushing 21 'is captively fixed to the attachment module 3, i. pre-fixed and held captive here. In that regard, a kind of prefixing device is created by this construction.

At the lower end of the plug-in projection 21a, the spacer 21, here in the form of the spacer bush 21 ', transitions into a bushing base 21d with a wider radial extension, whereby a spacer stop 21e is formed, which is the maximum insertion depth of the plug-in projection 21a limited in the through hole 17. In this case, the length or height H of the engaging projection 17 in the bore 17 is less than or equal to the height or thickness D of the add-on module 3, that is, the material thickness D formed between the underside 3b and the top 3c in the region of the through-bore 17. The dimensioning of the spacer, the insertion projection, the diameter of the passage bore, etc. are coordinated so that the respective spacer holder 21, here in the form of the spacer bushings 21 ', at least with a small or slightest play is prefixed, so that at the subsequent final assembly when screwing the screws, the individual parts can automatically assume their optimal screwed position. For this reason, a tolerance play is provided between the spacer and the bore or add-on module 3, which preferably moves relative to one and in particular two perpendicular to each other, parallel to the underside 3b of the add-on module 3 and / or also perpendicular thereto in the direction of insertion, which is greater than 0.001 mm, in particular greater than 0.005 mm, 0.01 mm, 0.15 mm, 0.2 mm, etc. A clearance greater than 1 mm is generally not necessary. In the illustrated embodiment, however, not only the attachment module 3 is screwed to the base module 1, but at the same time also a component module 3, here in the form of an active component, for example in the form of a radio housing 5 ', by the mentioned screws 7 with attached.

Therefore, the component module 5 also has at its two opposite fastening edges 5a (sometimes also called fastening flanges 5a) with a similar spacing sequence further insertion holes 19 which are formed on the laterally protruding fastening or housing flanges 5a. In the embodiment shown, at the bottom 5d of the component Module 5 in the region of the insertion holes 19 each support lugs 5c formed so that the component module 5 rests not with its entire bottom 3b but only with the bottom 5d of the Aufläge-lugs 5c directly on the upper side 3c of the add-on module 3.

Since, before joining all three components, the middle component, i. the add-on module 3 in the region of its through-holes 17 each captive fitted with the mentioned spacers, now the three modules can be placed on each other and aligned so that all mentioned holes, i. the insertion holes 19 in the component module 5, the through holes 17 in the add-on module 3 and the internal threaded holes 15 in the base module 1 are aligned with each other.

This results in the representation shown in Figures 3 to 5, wherein in this position then the mentioned screws respectively inserted through the insertion hole 19 and the passage bore 17 located underneath to the internal threaded bore 15 and then by tightening in the internal thread 15 'in the flange-shaped edge of the base module can be screwed until the bottom 7a of the respective screw head 7b rests on the upper side 5e of the component module 5 or the fastening flange and all three components can be firmly screwed together. Due to the described overall structure compared to conventional solutions significantly improved conditions, with the simplest structure and configurations. Above all, this reduces or reduces intermodulation even completely avoided. This can also be referred to as an intermodulation fixed screw connection. Finally, the materials of the individual modules and / or the material of the spacer may consist of the same materials or of different materials. Above all, it can be ensured by appropriate choice of the material of the spacer or a suitable material for a surface coating of the spacer that this selected material is particularly suitable, both in terms of the material of the base module as in relation to the material of the mounting module and / or on the material of the component module, if these should consist of different materials or surface coatings.

Based on Figure 6 is shown only schematically that with the described structure, the add-on module 3 can be attached to the base module 1 alone using the corresponding spacers 21, so without the component module 5 shown with reference to Figures 1 to 5. Again the captive prefixing of the spacer in the respective passage bore 17 in the add-on module 3 proves to be advantageous.

Finally, it should be pointed out that the step-like increasing rings or annular enlargements 21f on the outside of the spacer bushes 21 'are not absolutely necessary. However, these approaches offer the possibility under certain circumstances add-on modules 3 with different bore diameter at different Finally, the distance X (Figures 5 and 6) between the top of the base module 1 and the bottom of the add-on module 3 can be preselected differently without the need for different spacers 21 are required.

In the following, reference is made to a second exemplary embodiment according to FIGS. 7 et seq. The exemplary embodiment according to FIGS. 7 et seq. Differs from the preceding embodiment only in that the component module 5 does not rest directly on its support lugs 5 c on the upper side of the add-on module 3 in the screwed state, but that here between the add-on module 3 and the base module 1, a further or second spacer 121 is provided in the form of a spacer bushing 121 '. The initially described spacer 21, which may also be referred to as the first spacer 21, forms with the further or second spacer 121 quasi a combination spacer K.

As can be seen in particular from the cross-sectional illustration according to FIGS. 9, 10 and 11, the height or length H of the plug-in projection 21a of the first spacer 21 is now enlarged, and here has a dimension which is greater than the thickness D of FIG In other words, the radial projection 21c explained above ends at the insertion projection 21a of the spacer 21 formed here in the form of a spacer bushing 21 'in a plane above the upper side 3c of the add-on module 3. However, this upper side 3c of the add-on module 3 is positioned the mentioned second spacer 121, here in the form of a second spacer bushing 121 ', which has an inner bore 116 which is opposite to the insertion direction 20 of a drill diameter larger than the bore diameter of the throughbore 17 in the add-on module 3, merges into a conically tapered section, whereby an undercut 131 is formed. After insertion of the spacer 21, the radial projection 21c of the insertion projection 21a comes to lie at the end of this undercut 131, which passes from a narrower bore diameter to a larger bore diameter in the insertion direction, so that the two spacers 21 and 121, ie so-called combination spacer K come to rest under sandwich-like recording of the assembly or borehole section of the add-on module 3, whereby the add-on module 3 with the two spacers 21 and 121 is prefixed to each other captive.

In the embodiment according to Figures 1 to 6, the diameter in the region of the radial projection 21c of the plug 21a, i. the outer diameter at least in the undeformed state, a measure which is at least slightly larger than the drill diameter in the add-on module 3 in that area in which no undercut 31 is provided.

In the exemplary embodiment according to FIGS. 7 et seq., The outside or diameter dimension of the radially protruding projection 21 c, that is to say the so-called detent ring (with or without a detent finger formed there), is likewise at least slightly larger than the diameter dimension of the through-projection. The adjoining second spacer 121 has an internal dimension in the region of the through-bore, which initially preferably increases from the drill diameter 17 in the attachment module 3 by the hair-cutting 131 immediately following in the insertion direction and then into a borehole 116 with an inner diameter, which is greater than the inner diameter of the borehole 17 in the add-on module 3.

After such pre-fixing can then, as explained with reference to the first embodiment, the three modules 1, 3 and 5 are positioned in alignment with each other, in such a way that the corresponding holes in the individual modules are aligned with each other. In this cross-sectional illustration, shown in particular in FIGS. 7 et seq., The mentioned screws 7 can then be inserted from the rear side of the component module 5 through the drill holes and then screwed into the respectively lowest-lying internally threaded bore 15 in the base module 3 until the underside 7 a of the screw head of the screw 7 rest firmly on the upper side of the base module 1 and all three modules are firmly fixed to one another with the generation of sufficient contact forces.

Since, in this case too, the mentioned combination spacers 21, 121 have at least a slight play, when the screws are tightened it is ensured that all the components mentioned, including the two spacer bushings 21 and 121, can carry out relative movements slightly relative to one another, if necessary clearly reproduced contact conditions generate, which counteract the formation or increase of intermodulation.

In this case, in this embodiment, an additional distance Y is generated on the underside of the component module 5 and the top of the add-on module 3. In addition, it is not necessary in this exemplary embodiment for the support 5c projecting in the mounting direction to be formed on the underside 5d of the component module 5, as is preferably provided in the first exemplary embodiment. In this case, in the component module 5 provided in the first embodiment on its underside raised support lugs 5c may also be provided. Preferably, however, this can be dispensed with in particular in the case of the embodiment explained last, which in turn contributes to manufacturing advantages.

By way of derogation from FIG. 12, it is reproduced, similar to the cross-sectional illustration according to FIG. 6, that using the combination spacer, ie the first and second spacers 21, 121, a corresponding screw connection is only made between the base module 1 and the add-on module 3 can. In this case, the underside 7a of the screw head 7b would rest on the upper side of the second spacer 121. It is described in detail that the base module 1 and the mounting module 3 are electrically conductive, usually made of metal and / or comprise an electrically conductive coating, ie surface coating or outer layer. The screws used in the present field always consist of metal or in particular steel screws (stainless), wherein the advantages of the invention in principle also when using plastic screws are feasible.

Claims

Mobile radio antenna with the following features

with a base module (1), which comprises a plurality of mounting sections (1a), in each of which an internally threaded bore (15 ¹ ) is formed,

with an attachment module (3), which has mounting sections (3a) with through-bores (17) introduced therein,

with spacers (21) between the base module (1) and the attachment module (3),

with a screw connection between the base module (1) and the attachment module (3) and between the base (1) and the attachment module (3) provided spacers (21), wherein the base module (1), the attachment module (3) and the Spacers (21) are electrically conductive,

the spacers (21) comprise spacer bores (16) which are aligned with the passage bores (17) in the add-on module (3) and the internally threaded bores (15 ') in the base module (1),

in the internally threaded bores (15 ') in the base module (1) screws (7) are screwed in, which are the Durchtritts- through holes (17) and the spacers (21),

there is a prefixing device, by means of which the spacers (21) on the attachment module (3) are already prefixed to one another in the unassembled state, for which purpose the prefixing device has a spacer base (21d) and one of the spacer base (21d) in the plug-in direction (20) protruding plug projection (21a) comprises,

- The plug-in approach (21a) has in the insertion direction (20) relative to the spacer base (21d) offset lying on a radial projection (21c),

the radial projection (21c) engages in an undercut (31, 131),

- the undercut (31, 131)

a) is in the through hole (17) in the add-on module (3) provided so that the diameter of the passage bore (17) merges in the insertion direction (20) in the undercut (31) with a larger diameter, or

b) is provided in a second electrically conductive spacer (121) positioned on the mounting module (3) on the opposite side of the first spacer (21), the second spacer (121) having a spacer bore (11) Undercut (131) which widens in the direction of insertion.

2. Mobile radio antenna according to claim 1, characterized in that on the base module (1) opposite side of the add-on module (3) in addition a component module (5) is fixed, including the component Module (5) with insertion holes (19) is provided, which are aligned with the through holes (17) in the add-on module (3) and the internal threaded holes (15 ') in the base module (1), wherein in the assembled state, the underside (7 a) of the screw heads ( 7b) at least indirectly rest on the side opposite the mounting module (3) side of the base module (1).

3. A mobile radio antenna according to claim 1 or 2, character- ized in that the insertion projection (21a) of the spacer (21) stop limited in the through hole (17) in the add-on module (3) can be inserted.

4. Mobile radio antenna according to claim 3, characterized in that the spacers (21) in the insertion direction

(20) trailing a stop (21 e) formed by the spacer base (21 d), which projects beyond the plug projection (21 a) in the radial direction transversely to the plug-in direction (20), wherein the stop (21 e) upon reaching the maximum insertion depth of the plug-in extension

(21 a) in the through hole (17) at the bottom

(3b) of the add-on module (3) abuts.

5. Mobile radio antenna according to one of claims 1 to 4, characterized in that the spacers (21) comprise a plurality of spacer bushes (21 ') with spacer bores (16), which at least two and preferably more stepped stepped on its outer periphery Have sections (21f) with different outer diameter.

6. Screw connection according to one of claims 1 to 5, characterized in that the plug projections (21 a) of Spacer (21) have an insertion height (H) with which they project beyond the plug-in approach (21a), wherein the insertion height (H) is less than or equal to the thickness (D) of the add-on module (3) in the region of its passage bore (17).

7. A mobile radio antenna according to one of claims 1 to 5, characterized in that the insertion projections (21a) of the spacers (21) have an insertion height (H), with which they project beyond the plug-in projection (21a), wherein the insertion height (H) is greater as the thickness (D) of the add - on module (3) in the region of its passage bore (17), wherein the radial projection (21c) is arranged in the undercut (131) of the second spacer (121).

8. Mobile antenna according to one of claims 1 to 5, characterized in that the insertion projection (21a) to its radial projection (21c) at least in sections with a thinner material cross-section for generating at least one partial elasticity is formed.

9. Mobile radio antenna according to one of claims 1 to 8, characterized in that the first and / or second spacer (21, 121) comprises a conductive surface coating or consists of metal.

10. Mobile radio antenna according to one of claims 1 to 9, characterized in that the base module (1), the attachment module (3) and / or the spacers (21, 121) made of the same materials or of different materials.