EP1602144B1 - High-frequency connection and high-frequency distribution network - Google Patents

Abstract

An improved radio-frequency or network connection including a basic module having two or more basic signal coupling surfaces, and a network module having two or more network signal coupling surfaces. The basic module has a basic ground coupling surface, and the network module has a network ground coupling surface. In the operating state, the basic ground coupling surface is capacitively RF coupled to the network ground coupling surface, and is aligned parallel thereto.

Description

The invention relates to a high-frequency or network connection according to the preamble of claim 1.

In particular, in the antenna technology - but not only there - it sometimes turns out to be difficult to create intermodulation-free connections or connections. This problem arises mainly at interfaces where different modules are to be used if necessary.

High frequency connections between two radio frequency modules, such as between a radio frequency board and a wireless transmission device such as antennas, are normally realized by means of coaxial connection techniques. But even here adverse and undesirable intermodulation can occur. Improvements to avoid or reduce passive intermodulation in the use of coaxial connectors are for example in the US Pat. No. 6,414,636 B1 been proposed. But if, for example, in a so-called smart antenna, as they basically from the US Pat. No. 6,463,303 B1 It is known that a certain distribution network can be switched on in order to generate a specific beam characteristic with respect to the antenna in question, in addition the costs for such a connectable module can also increase remarkably if all the input and output connection connections take the form of coaxial plug connections be executed.

Therefore, in principle, it could also be thought of to provide capacitive connections instead of coaxial connectors.

A generic high-frequency connection is from the US 5 986 519 A , as the closest prior art, become known. It is an arrangement for transmitting high frequency microwave signals between a cable and a printed microstrip circuit feed network disposed on a dielectric substrate in a microwave antenna structure. So there is a solid structure in the manner of a triplate structure that includes two parallel ground planes.

In this case, this multilayer structure also has at least one so-called transition printed circuit board, on which a connecting line structure is formed which ends in so-called coupling surfaces. Parallel and above this transition printed circuit board, a divided dielectric is arranged, on each of which a coupling surface is formed, which is connected to a line structure. These coupling surfaces come parallel and adjacent to the interconnected on the transition board coupling surfaces to lie. The coupling surfaces on the transition printed circuit board can also be formed from the metallized line itself, said electrical line is at least indirectly electrically-galvanically connected to the inner conductor of a coaxial cable.

This two-layered structure with a printed circuit board structure and a dielectric that builds up thereon is sandwiched between a lower so-called first ground plane and an upper so-called second ground plane, wherein the lower ground plane is electrically-galvanically connected to the outer conductor of the coaxial cable and the second ground plane is reactively coupled to the first ground plane is.

Such a triplate design thus comprises a microstrip circuit arrangement on a first dielectric substrate and a second microstrip circuit formed on an intermediate dielectric substrate, whereby all microwave signals from a coaxial cable connection via the printed interposer circuit to the microstrip circuit on the first coupled dielectric substrate.

A PCMCIA signal connector, as it is usually used in notebooks, is basically from the U.S. Patent 5,936,841 known. The PCMCIA plug-in card usually has on its one end face a connector strip, which interacts with a built-in notebook power strip when the corresponding PCMCIA card is inserted into a receiving slot in the notebook. On one of the large side surfaces is then parallel to this side surface a first electrically provided conductive layer, which represents one half of the RF coupling device. The second parallel electrically conductive layer is housed with lateral offset in the interior of the device. Between two mutually parallel conductive layers of the RF coupling structure is an air gap (generated by the side clearance between PCMCIA card and adjacent inner boundary surface of the insertion slot of the electrical device, for example in the form of the notebook) and a dielectric interlayer, the part of the wall of the Notbooks is.

But even with such a PCMCIA card with a capacitive RF connection, the unwanted intermodulation can not be avoided.

The object of the present invention is therefore to provide a high-frequency connection and in particular a high-frequency distribution network, which can be used as needed on a designated interface, with intermodulation should be largely avoided or excluded.

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

It is now provided that an RF network is coupled to a base module in such a way that at least one first signal path from the base module leads to the network and at least one second signal path originates from the network to the base module, in such a way that not only a capacitive coupling between the ground potential areas, but above all between the signal coupling surfaces of the base module and the network module is formed both in the at least first as well as the at least second signal path.

This also offers the possibility of inserting such a network module, for example into slot openings in an antenna, so that the corresponding capacitive signal paths are provided in the finally inserted position.

In this case, the construction is such that an intermodulation-free modular connection, for example an RF network to a base module, is made possible by the production of a potential-free, ie a capacitive high-frequency connection at a corresponding interface. In this case, not only the signal leading signal lines, but also the outer conductor or grounds are coupled to avoid potential galvanic contact floating to each other at the corresponding contact devices. The type of interface in the form of capacitive coupling via an interface with contacts, has the significant advantage of low intermodulation, which is just of great importance in mobile phone applications such as mobile radio antennas. If very high intermodulation products in the transmission frequency range, whose frequency in the reception frequency range rich, could be received at these reception frequencies no weak signals from mobile devices such as mobile phones more.

That based on this principle an intermodulation-free modular connection of an RF network with several, in particular with more than two terminals or connection points to an RF device, such as a mobile phone realize, is surprising from several points of view. Because it would have been to be assumed that in training of corresponding mutually parallel coupling surfaces at which the respective RF signal is to be transmitted, as well as for the production of the potential-free ground connection, make further influences noticeable that prevent it an always clearly reproducible RF coupling connection can be produced. Because even with the use of mobile antennas or transmitting antennas, it is imperative to use a metallic housing for shielding. However, metallic housings basically have an effect on the electrical conditions and properties when capacitive coupling devices are used inside the shielded housing. Because the distance between the coupling surfaces and the shield case may cause additional parasitic parallel capacitance between the coupling surfaces and the electrical ground.

However, these effects and effects can also be minimized by the construction of the HF connection device according to the invention.

The geometry of the coupling surfaces determines the electrical parameters of the signal transmission, such as the adaptation to the characteristic impedance (VSWR), the insertion loss and the broadband frequency range. In order to further improve fine tuning, in a preferred development of the invention it is further provided that, for example the coupling surface on a board used with laterally projecting "flag" or so-called "extension surfaces" is provided. These flags or extension surfaces cause parallel to the coupling between the coupling surfaces an additional low coupling between the coupling surfaces on a circuit board and a mass surface.

The network module, which can be coupled to a base module, furthermore has capacitively coupled mass areas in addition to the coupling surfaces effecting a capacitive RF coupling in order to suppress the intermodulation-free modular connection. The metal structure covering this circuit board is formed on the side on which the corresponding electrical mass areas of the base module lie. In this case, an insulating film with a predefined thickness is preferably used for the isolation between the two mass coupling causing electrical ground surfaces. In contrast, the coupling surfaces of the electrical ground planes effecting the signal transmission, which are sometimes also referred to as coupling fingers, are preferably formed on the opposite side of the board of the network module, so that the substrate of the board is insulated from the corresponding signal coupling surface at the base. Module works.

At least one signal path from a base module is fed back via the capacitive coupling to a network module and from this network module via at least one further signal path to the antenna or, for example, the base module. This can be done by plugging different network cards a closed signal path can be realized via the network card, wherein at the input and the output of the network card, the signal path is designed capacitively.

The high-frequency network can be embodied on the mentioned circuit board, for example in stripline technology (microstrip).

Figur 1:

eine schematische perspektivische Teilansicht einer Mobilfunkantenne mit zwei an der Unterseite einsteck- und ausziehbaren Basis-Moduleinrichtungen, die jeweils zur Aufnahme eines Netzwerk-Moduls geeignet sind;

Figur 2:

eine schematische Darstellung des Grundaufbaus des Basis-Moduls und des Netzwerk-Moduls unter Erzeugung einer potentialfreien HF-Verbindung;

Figur 3:

eine schematische perspektivische Darstellung des Basis-Moduls und des Netzwerk-Moduls zur Erläuterung der potentialfreien HF-Kopplung;

Figur 4:

eine schematische auszugsweise Draufsicht auf zusammenwirkende Koppelflächen des Basis- und des Netzwerk-Moduls.

Figur 5:

eine zu Figur 3 entsprechende Darstellung zur Erläuterung eines anderen Verbindungsmechanismus zwischen beiden Modulen;

Figur 6:

eine schematische auszugsweise perspektivische Darstellung eines Basis- und eines Netzwerk-Moduls in Explosionsdarstellung;

Figur 7:

eine schematische Querschnittsdarstellung durch das Ausführungsbeispiel gemäß Figur 5 im zusammengebauten Zustand;

Figur 8:

eine vergrößerte Detaildarstellung aus der Querschnittsdarstellung gemäß Figur 6.

Further advantages, details and features of the invention will become apparent from the following explained with reference to drawings embodiment. In detail:

FIG. 1:

a schematic perspective partial view of a mobile radio antenna with two at the bottom insertable and extendable base module devices, each of which is suitable for receiving a network module;

FIG. 2:

a schematic representation of the basic structure of the base module and the network module to produce a potential-free RF connection;

FIG. 3:

a schematic perspective view of the base module and the network module to explain the potential-free RF coupling;

FIG. 4:

a schematic partial top view of cooperating coupling surfaces of the base and the network module.

FIG. 5:

one too FIG. 3 corresponding representation for Explanation of another connection mechanism between both modules;

FIG. 6:

a schematic excerpt perspective view of a base and a network module in an exploded view;

FIG. 7:

a schematic cross-sectional view through the embodiment according to FIG. 5 in the assembled state;

FIG. 8:

an enlarged detail representation of the cross-sectional view according to FIG. 6 ,

In FIG. 1 is a schematic excerpt perspective view of a mobile radio antenna 1, a base station shown. The housing cover of the antenna device, namely the so-called radome 3, can be seen in part. The antenna is held and positioned overall via an antenna mast 5. On the underside 7 of the housing cover 3, a slot opening is provided, in which parallel and independently two base modules 9 can be inserted, which cooperate with two interchangeable network modules 11, respectively.

On the network modules 11 specific, formed for example in stripline technology network components and network circuits are provided so that by using a correspondingly adapted network module 11, a specific beam characteristic of the antenna is generated. The explained network modules 11 thus serve to generate a specific beam characteristic a so-called smart antenna, such as in the US Pat. No. 6,463,303 B1 or in the PCT publication WO 01/59 876 A1 is described. Accordingly, in an antenna therefore also several base and associated network modules can be provided.

Based on FIG. 2 the schematic structure with respect to a cooperating module pair is shown, with a base module 9 and a network module 11. Only with reference to two signal lines 13 and two ground lines 15 is shown that the respective network module 11 completely potential-free via a corresponding HF connection 17 is coupled to the relevant base module 9.

The respective ground potential GND1 lies only on the base module 9 and the ground potential GND2 is applied only to the network module. In this case, corresponding potential-free connections between the base module 9 and the network module 11 via one or more signal paths 14 and 16 are provided.

Based on FIG. 3 and FIG. 4 Now, a schematic basic structure of the two modules is reproduced in greater detail.

Basically, the base module 9 comprises an electrically shielded base plate or base 21, which is generally made entirely of metal. In the following, the term base plate 21 is frequently used. This electrically conductive base or base plate 21 is provided with recesses or windows 23, in which electrically conductive base signal coupling surfaces 25 are formed. These base signal coupling surfaces 25 are separated from the electrically conductive base 21 by a respective circumferential gap 26 or other insulation, which forms a base mass coupling surface 27 adjacent to the base signal coupling surface 25. In the illustrated embodiment according to FIG. 3 three connection points 29 are shown at the base, to each of which a coaxial conductor 31 leads, wherein the inner conductor 31a of each coaxial conductor 31 is soldered to the base signal coupling surface 25 and to a stripped outer peripheral region of the associated outer conductor 31b via a corresponding solder joint 31c with the base Mass coupling surface 27 is electrically connected.

The corresponding network module 11 has a circuit board 35 with associated substrate 35 'on which connection points 129 on the base module corresponding to the connection points 29 are formed on the network module 11. Often it is spoken by a network board 35 instead of board 35.

The connection points 129 on the network module 11 comprise network signal coupling surfaces 125 which, in the exemplary embodiment shown, are also rectangular in shape from the basic shape, ie comparable to the respective shape of the base signal coupling surfaces 25.

About each stripline 37 is the network signal coupling surface 125 with an in FIG. 3 only schematically indicated network 39 is connected, which represents an RF module. This is preferably provided and formed on the upper side 35a of the circuit board 35, that is to say on the side of the circuit board 35 which is opposite to the cooperating base, that is to say the so-called network board 35.

Furthermore, the network module 11 also includes a large-area designed mass coupling surface, namely a network mass coupling surface 127, which in the embodiment shown but not on the same side of the board 35, on which the connection points 129 are provided, but on the bottom is formed , In the illustrated embodiment, the electrically conductive network mass surface 127 is at least approximately rectangular in shape and extends with its peripheral boundary line 129 'to the immediate vicinity of the connection points 129. In the operating state, the board 35 is moved to the base and positioned according to the arrow 41, namely with the interposition of an electrically insulating intermediate layer, preferably in the form of an insulating film 43, the size and shape of which corresponds to the network mass coupling surface 127 or is slightly larger. This prevents that the network mass coupling surface 127 can contact the base mass coupling surface 27 to produce a galvanic electrical connection. By using an insulating film 43 with a predetermined thickness, a clearly defined distance between the base mass coupling surface 27 and the network mass coupling surface 127 is realized, whereby clearly reproducible electrical conditions can be generated.

Based on FIG. 4 is shown in a schematic plan view corresponding to the layers of the mass coupling surfaces and the insulating film and the network mass coupling surface 127 in relation to the underlying base mass coupling surface 27. It can also be seen that the base mass coupling surface 27 can be dimensioned larger, for example, in the longitudinal as well as in the transverse direction than in the network mass coupling surface 127. For fine tuning, it is further provided that the network coupling surfaces 127 project laterally Flag or extension sections 127 'may be provided, resulting in the embodiment shown, a cross structure, but this is not absolutely necessary. These flags or extension portions 125 'cause parallel to the coupling between the coupling surfaces 25, 125 an additional small coupling between the coupling surfaces 125 on the board 35 and the base mass coupling surface 27. The reason for this lies in a small distance of these flags or extension sections 127' to Base mass coupling surface 27 compared to the distance of the network signal coupling surface 125 relative to the base mass coupling surface 27th

In assembled position, in which, as explained, the board 35 rests on the base 21, the desired unique relationships are reproduced. This can be generated for example by a sliding mechanism, which makes it possible to bring the network module 11 with the board 35 in the desired unique relative position to the base module 9 and to hold in this position and to fix.

Based on FIG. 5 is merely shown that, for example instead of a sliding mechanism (which includes, for example, two laterally opposite groove receiving, in which the board 35 can be inserted) may also be provided a kind of tilting mechanism. In the embodiment according to FIG. 5 is a schematically designed as a U-shaped recess tilt bracket 45 is used, in which the one boundary edge 35 "of the board 35 inserted and then the board 35 can be pivoted about the tilting axis formed on the base 21 until the board 35 with intermediate positioning of said Insulating film 43 rests on the base 21.

Based on FIGS. 6 to 8 Now, a possible structure of the base and the network module 9, 11 is explained with further details, the basic principle remains unchanged.

In the embodiment according to the FIGS. 6 to 8 the base 21 is formed in cross-sectional view in the form of a low-height U-shaped electrically conductive sheet, which is provided with laterally opposite flanges 21 '.

In the area of the flange sections 21 ', a plurality of coaxial cables 31 are supplied to the base module 9 from each side, wherein the individual coaxial conductor sections or coaxial conductors 31, as already explained, are led to the base signal coupling surfaces 25. The outer conductor 31b of the respective coaxial conductor 31 is contacted on the side legs of the U-shaped base 21, for example, by an electrical solder connection electrically to the electrically conductive base 21, said through these side portions 21 ", the inner conductor 31a of the coaxial 31 are passed and soldered via an electrical solder connection to the respective base signal coupling surfaces 25.

These basic signal coupling surfaces 25 are electrically insulated from the base mass coupling surface 27 by a circumferential insulating gap 26. In other words, the base signal coupling surfaces 25 lie in a corresponding larger-dimensioned window 23, so that the insulating gap 26 is formed between the base signal coupling surfaces 25 and the base mass coupling surfaces 27.

On the underside of the base 21, a shielding wall 49 is ultimately provided to produce a total shielding. Another Schirmungswand 50 is placed from above on the base module 9 thus formed as part of this base module 9 and can then be screwed together by using screws to holes 51. The upper Schirmungswand 50 is also formed in cross section U-shaped with outboard flange portions 50 'and side legs 50 ", wherein in the region of the supplied coaxial cables and coaxial 31 corresponding slot recesses 52 are incorporated in the vertical leg portion 50'.

The explained base module 9 thus serves to accommodate a network module 11, which in FIG. 6 is shown in exploded view.

Also, the network module 11 comprises, in addition to the already explained board 35 and the network 39 thereon, a surrounding housing 53, which is seated with its wall sections 53 'on the outer circumference of the board 35 or connected thereto is, to form an interior space 55, in which, as explained on the board 35, the corresponding assemblies and lines for generating the network 39 are formed and provided.

It can be seen from the cross-sectional illustration that the network signal coupling surfaces 125 come to lie directly above the base signal coupling surfaces 25, wherein the material of the printed circuit board, ie the substrate 35 'forms the insulation between the network signal coupling surface 125 and the base signal coupling surface 25. The base signal coupling surfaces 25 are electrically conductively connected via a downwardly extending connection section 25 'to the inner conductor 31a of an associated coaxial conductor 31 projecting thereon, for example via a solder connection.

As can also be seen from the cross-sectional view, is also in the FIGS. 7 and 8th reproduced electrically insulating support 59 provided in the form of a spacer, on which on the one hand, the electrical ground, ie the base-mass coupling surface 27 and on the other hand, the base signal coupling surface 25 rests. Since the signal coupling surface 25 has a thinner material cross-section than the base-mass coupling surface 27, therefore, the aforementioned spacer 59 is formed stepped. In order to ensure a unique Justiersitz, recesses or, for example, bores 61 are immediately offset inwardly lying to the boundary edge of the window-shaped recesses or the Isolierspaltes 26 is provided, in which the spacer 59 with a slightly further upwardly projecting portion 59 'in this recess or bore 61 protrudes.

Thus, a network module 11 formed in this way can thus be pushed without problems into the associated base module 9, for example, with the network module 11 at an asymmetrical location, for example at the., For the correct insertion of the network module 11 (housing cover 50) Has an elevation 163, which cooperates with a corresponding elevation or recess - 63 on the inside of the housing cover of the base module 9 ( FIG. 6 ).

Claims (18)

1. High-frequency (HF) or network connection having the following features:

   - a base module (9) is provided,

   - the base module (9) comprising a plurality of base signal coupling surfaces (25) on one side of an associated base plate (21),

   - a network module (11) is provided,

   - the network module (11) comprising a plurality of network signal coupling surfaces (125) on one side of an associated network plate (35), which are capacitively coupled with the associated base signal coupling surfaces (25),

   - the base module (9) has a base-ground coupling surface (27),

   - the network module (11) has a network-ground coupling surface (127),

   - in operation the base-ground coupling surface (27) is capacitively coupled with parallel alignment to the network-ground coupling surface (127),

   - the network module (11) can be positioned or is positioned in or on the base module (9) such that a capacitive high-frequency signal connection is produced via the at least one network signal coupling surface (125) and the base signal coupling surface (25) which is positioned parallel with the network signal coupling surface (125), characterized by the following further features:

   - at least one first signal path (14) is realized from the base module (9) to the network module (11) via at least one first base signal coupling surface (25) and one network signal coupling surface (125), interacting therewith, and at least one second signal path (16) is realized from the network module (11) to the base module (9) via at least one further network signal coupling surface (125) and one base signal coupling surface (25), interacting therewith,

   - the plurality of base signal coupling surfaces (25) of the base module (9) are connected in each case to an associated cable (31),

   - the base signal coupling surfaces (25) and the base-ground coupling surface (27) are provided on the same side of the base plate (21),

   - the network module (11) on the side of the network plate (35) lying away from the base signal coupling surfaces (25) has a plurality of network signal coupling surfaces (125), and

   - the network-ground coupling surface (127) is provided on the side of the network plate (35) of the network module (11) lying opposite the network signal coupling surfaces (125).
2. High-frequency or network connection according to Claim 1 characterized in that in the case of the network module (11) inserted in or placed on the base module (9) the network-ground coupling surface (127) rests directly adjacent on the base-ground coupling surface (27), to be precise with insulation or an insulating foil (43) interconnected.
3. High-frequency or network connection according to either of Claims 1 and 2, characterized in that the base signal coupling surfaces (25) are arranged in a window or a recess (23) in an electrically conductive base plate (21), wherein the windows or recesses (23) are dimensioned at least slightly larger than the base signal coupling surfaces (25) located therein, which is therefore insulated from the base-ground coupling surface (27) by a circular insulating gap (26).
4. High-frequency or network connection according to any one of Claims 1 to 3, characterized in that the base signal coupling surfaces (25) are in each case electrically connected to an inner conductor (31a) of a coaxial conductor (31), preferably by means of a solder joint (31c).
5. High-frequency or network connection according to Claim 4, characterized in that the base signal coupling surfaces (25) have a connecting section (25'), leading to a lower plane, which reaches at least as far as the height of an inner conductor (31a), axially projecting from a coaxial conductor (31), with a solder joint produced.
6. High-frequency or network connection according to any one of Claims 1 to 5, characterized in that the network coupling surface (127) is dimensioned smaller than the base-ground coupling surface (27), interacting therewith, the limit edge (129') of the network-ground coupling surface (127) running staggered to the network signal coupling surfaces (125).
7. High-frequency or network connection according to Claim 6, characterized in that the network signal coupling surfaces (125) are connected by means of a strip line (37) to the network (39) provided on the network plate (35).
8. High-frequency or network connection according to any one of Claims 1 to 7, characterized in that, in plan view, the basic structure of the base signal coupling surface (25) and of the network signal coupling surface (125) is such that the base signal coupling surface (25) is configured longer and broader than the network signal coupling surface (125) and, in plan view, the network signal coupling surface (125) comes to lie in an overlapping position.
9. High-frequency or network connection according to any one of Claims 1 to 8, characterized in that at least the network signal coupling surfaces (125) are provided with tags or extension sections (125') projecting further sideways, as the result of which fine tuning of the coupling effect or modulation can be achieved.
10. High-frequency or network connection according to Claim 9, characterized in that the tags or extension sections (125') project sideways so far from the network signal coupling surfaces (125) that a coupling effect with the base-ground coupling surface (27) can be produced thereby.
11. High-frequency or network connection according to any one of Claims 1 to 10, characterized in that the base plate (21) of the base module (9) lies on a support or a spacer (59), which is preferably arranged at least in the region of the base signal coupling surfaces (25).
12. High-frequency or network connection according to any one of Claims 1 to 11, characterized in that the cross-section of the base plate (21) has at least an approximate U-shape, and to be precise forming lateral protruding flanges (21'), which lie offset to the plane of the base plate (21), and in that the base plate (21) with the flanges (21') is connected to connection side pieces (21"), running diagonally to the base plate (21), in which recesses or drillings (52) are arranged, through which an inner conductor (31a), insulated against the connection side piece (21"), is passed and wherein the outer conductor (31b) of a coaxial conductor (31), to be attached, is electro-galvanically connected to the flange (21') and/or the connection side piece (21").
13. High-frequency or network connection according to either of Claims 11 and 12, characterized in that the base signal coupling surface (25) and the base-ground coupling surface (27) are on the same elevation plane.
14. High-frequency or network connection according to any one of Claims 1 to 13, characterized in that the material thickness of the base signal coupling surfaces (25) is less than the material thickness of the base-ground coupling surface (27).
15. High-frequency or the network connection according to any one of Claims 12 to 14, characterized in that a positioning mechanism in the form of recesses or projections (61, 63), gripping one another, is provided, by means of which the support or the support holder (59) can be positioned in exact relative situation to the base signal coupling surface (25) or the base-ground coupling surface (27).
16. High-frequency or network connection according to any one of Claims 1 to 15, characterized in that the base module (9), apart from a lower insulating cover (49), comprises a housing cover (50) rising thereover at a distance, which is preferably provided with two opposite-facing flange sections (50'), the cover (49) at its edge and the housing cover (50) in the region of its flange sections (50') being able to be joined together, preferably with inclusion of a flange section (21'), arranged in-between, of the base plate (21).
17. High-frequency or network connection according to any one of Claims 1 to 16, characterized in that the network module (11) comprises an enclosing housing or an enclosing housing cover (53), which while forming an interior preferably sits on the edge of the network plate (35) or is connected therewith.
18. High-frequency or network connection according to any one of Claims 1 to 17, characterized in that the network module (11) can be inserted in a suitable receptacle space of the base module (9), the receptacle space in the base module (9) as well as the cross section of the insertable network module (11) being assymetric, so that the network module (11) can only be inserted into the base module (9) in a pre-defined relative situation.

Images