EP1601046B1 - Array antenna equipped with a housing - Google Patents

Description

The present invention relates to antenna arrangements.

The radiating elements of a single or array antenna are often attached to a stable frame or box structure, which structure serves as a support for the various antenna elements and at the same time gives the antenna the necessary mechanical stability.

It is a problem of the known antennas that they are expensive and heavy. In addition, the installation of the antennas and attachment to a mast or building is cumbersome. Another disadvantage of known antennas is that they are not suitable for simple and reliable mass production. This is a particularly important point if the production is to be carried out by untrained forces.

Based on the above-mentioned prior art, the task is an antenna with a To provide antenna housing, which is simple and inexpensive and still has the necessary strength.

It is another object of the invention to provide a group antenna comprising a number of dipole antennas.

1. a) mehrere Strahlelemente,
2. b) eine Schaltungsplatte mit Ansteuerschaltung zur Aufnahme des Strahlelemente.

According to the invention, a group antenna according to claim 1 is provided with a plurality of radiation elements. The antenna comprises a (rear) wall made of composite materials and designed as a support for the antenna's internal antenna elements. A radome having a thin, hard, RF or HF-capable shell serves as a kind of cover which can be connected to a terminal portion of the (back) wall so as to form an antenna housing together with the backplane. Between the (back) wall and the radome, a RF or HF capable foam core is arranged. The following antenna elements are hermetically protected in the housing:

1. a) a plurality of radiation elements,
2. b) a circuit board with drive circuit for receiving the radiating elements.

Further embodiments of the invention can be found in the dependent claims 2 to 20.
The Patent Application GB2373100 discloses the preamble of independent claim 1.

• Fig. 1A eine (Gruppen-)Antenne gemäss Erfindung in einer schematischen Explosionsansicht;
• Fig. 1B die (Gruppen-)Antenne gemäss Fig. 1A in einer anderen Explosionsansicht;
• Fig. 2A einen schematischen Schnitt durch einen Teil einer weiteren Antenne gemäss Erfindung;
• Fig. 2B die Antenne gemäss Fig. 2A in einer Draufsicht;
• Fig. 3 eine Ansicht eines Teils einer Ansteuerschaltung, gemäss Erfindung;
• Fig. 4 einen schematischen Schnitt durch einen Teil einer weiteren Antenne gemäss Erfindung;
• Fig. 5A einen schematischen Schnitt durch einen Teil einer weiteren Antenne gemäss Erfindung;
• Fig. 5B eine schematische Draufsicht auf einen Bereich der in Fig. 5A gezeigten Antenne;
• Fig. 6 eine schematische Draufsicht einer weiteren Antenne gemäss Erfindung.

The invention is described in detail below with reference to embodiments illustrated in the drawings. Symmetry planes are indicated in the drawings by dashed lines and imaginary areas by dotted lines, where this is necessary for a clearer presentation of the invention. Show it:

• Fig. 1A a (group) antenna according to the invention in a schematic exploded view;
• Fig. 1B the (group) antenna according to Fig. 1A in another exploded view;
• Fig. 2A a schematic section through a part of another antenna according to the invention;
• Fig. 2B the antenna according to Fig. 2A in a plan view;
• Fig. 3 a view of a part of a drive circuit according to the invention;
• Fig. 4 a schematic section through a part of another antenna according to the invention;
• Fig. 5A a schematic section through a part of another antenna according to the invention;
• Fig. 5B a schematic plan view of an area of in Fig. 5A shown antenna;
• Fig. 6 a schematic plan view of another antenna according to the invention.

Detailed description:

In the following, terms are explained and defined that appear several times in the description and the claims.

As a wall or rear wall, an element is referred to, which is located in the rear region of an antenna housing or an antenna and is usually provided with fastening means to attach the antenna housing to a mast or building. The terms front, back, top, bottom and other directional indications are used in the description to describe the individual elements of an antenna with respect to the assembled state easier, without these terms are intended to limit the scope.

A radome is a type of envelope typically located in front of the antenna array and located in the receiving or transmitting area of the antenna. In order not to influence the transmission and / or reception characteristic of the antenna arrangement, the radome is typically made of materials which have no or only a slight damping effect. In other words, the radome includes materials that are suitable for RF or HF. The same applies to other components (for example, the foam core to be described) of the antenna housing and their materials, at least as far as they sit in the receiving or transmitting range of the antenna.

The following text speaks of radiant elements. These are three-dimensional jet elements, which consist for example of a cast part.

According to the invention, the term casting is to be understood as meaning moldings which have been produced by the (automatic) injection molding process. In this case, thermoplastically processable plastics are processed by means of an injection molding process. Instead of plastic, metals can also be used to make the castings. The moldings are characterized that a minimum of post-processing is necessary. In addition, the dimensions of the moldings are very precise. Further details on three-dimensional radiating elements can be found in the Swiss patent application entitled "Broadband Antenna with a 3-Dimensional Casting" filed on Dec. 23, 2002 under the application number 2002 2210/02 and disclosed under the number EP 1 434 300 A2 ,

It can reflectors are used, which preferably have a conductive surface. This conductive surface can be grounded. The reflector surface can be flat or curved. According to the invention, a metallized side of a circuit board is preferably used as a reflector.

Depending on the embodiment of the antennas, a drive circuit may comprise parts of a receiver and / or transmitter, for example. Polarization switch, amplifier stages or calibration elements.

A first antenna 10, according to the invention, is in the Figures 1A and 1B shown. An antenna 10 according to the invention comprises a back wall 11 made of composite materials and designed as a support for elements of the antenna 10 (referred to herein as antenna elements). The front of the antenna 10 is formed by a radome 12, which serves as a thin, hard, RF or RF-capable shell, which can be connected in the manner of a lid with a peripheral connection portion 11.1 of the rear wall 11. The radome 12 together with the rear wall 11 in the mounted state, an antenna housing for the various antenna elements. Within this antenna housing, the elements described below are arranged.

A circuit board 13 with an integrated drive circuit carries a plurality of radiation elements 14. The drive circuit is in the Figures 1A and 1B not visible. It is preferably located on the rear side of the circuit board 13. In the circuit board 13 connecting areas for receiving the beam elements 14 and for producing an electrically conductive connection of the beam elements 14 are provided with the drive circuit. In FIG. 1A Such a connection area is identified by the reference number 13.1. The front side of the circuit board 13 (in FIG Fig. 1A visible) is preferably metallized over the entire surface and has only in the connecting portions 13.1 holes or recesses in order to use the beam elements 14 and connect to the drive circuit on the back of the circuit board 13 can.

For the distortion-free production of the circuit board, it may be advantageous to provide the metal surface with a plurality of generally regular recesses, which are chosen so small in size compared to the wavelength that they have no significant effect on the electrical behavior of the antennas. The circuit board may, for. For example, be divided into several circuit boards for manufacturing reasons.

In the example of the invention shown, each of the radiating elements 14 has four legs. Each of the four legs is inserted into a hole in the circuit board 13 and back connected to the drive circuit. It may be a connector that automatically not only provides for a mechanical connection of the radiating elements 14 to the circuit board 13, but also provides an electrical connection to the drive circuit.

In the example of the invention shown, eight beam elements 14 are arranged in two columns with four beam elements 14 next to each other. Thus, the antenna 10 is a so-called group antenna.

Another component of the invention is a foam core 15, which is provided in the present example with recesses 15.1 for receiving the three-dimensional beam elements 14. In Fig. 1B more recesses 15.1 are shown than are really necessary. The foam core 15 preferably has as many recesses 15. 1 as the radiation elements 14 are used in the antenna 10. For manufacturing or weight reasons, but also a larger number of recesses be provided. It is important that the foam core 15 in the areas where it has no recesses 15.1, ie rests in the region of the webs between the recesses 15.1, at least partially flat on the front of the circuit board 13. In addition, it is important that the foam core 15 is at least in the receiving or transmitting range of the antenna 10 RF or RF-designed.

In the Figures 1A and 1B Further optional elements are shown, which are described below. As can be seen, the rear wall 11 has a series of connection means 16 which serve to be able to establish an electrically conductive connection between the drive circuit and external electronics, for example an amplifier. The connecting means 16 may be designed differently and arranged differently. Particularly suitable as a connecting means 16 are so-called flange connectors, which are also in the Figures 1A and 1B can be seen. The inner part of a flange connector may be soldered to a cable leading from the connector, for example, to the drive circuit. A flange connector is z. For example, from the inside through a hole in the rear wall (or side surface) 11 inserted and screwed from the outside with a nut (glued, pressed, hammered).

An optional foam bed 17 is provided, which in the example shown comprises a larger part 17.1 and a smaller part 17.2. The optional foam bed 17 essentially ensures that a planar support surface for the circuit board 13 and / or a further circuit board 13.2 is provided. In order to achieve this, recesses 17.3 for cables and a recess 17.4 for the further circuit board 13.2 are provided in the part 17.1. The front of the foam bed 17, i. that side which is directed towards the circuit board 13 is preferably flat.

In the in the Figures 1A and 1B As shown, optional pins 15.2 are provided on the foam core 15. The pins 15.2 may have a cylindrical or conical shape and serve to the Circuit board 13 to give a well-defined lateral position. For this purpose, the circuit board 13 may be provided with holes 13.4.

In the Fig. 1A can be seen, as already mentioned, that in addition to the circuit board 13, a further circuit board 13.2 is provided. This further circuit board 13.2 is preferably smaller than the circuit board 13 and can be plugged onto the circuit board 13 by means of plug connectors 13.3. Preferably, the connectors 13.3 are designed so that they produce both a mechanical and an electrical connection between the circuit board 13 and the other circuit board 13.2. Suhner® MMBX connectors from Huber + Suhner are particularly suitable, since these connectors are able to compensate for certain tolerances without interrupting the electrical connection.

Like from the Figures 1A and 1B it can be seen results in a novel antenna housing with layer structure, which is stable and compact. The layer structure is designed so that there is little or no room for movement for the individual antenna elements. The rear wall 11 is specially shaped to give the entire antenna 10 torsional rigidity and mechanical stability. In addition, the rear wall 11, depending on the assembly, must be designed so that it is able to absorb the enormous wind forces acting on the entire antenna 10. Only by a special embodiment of the rear wall 11, the antenna elements can be protected from inadmissible mechanical stresses.

The rear wall 11 preferably has connecting pieces or drive-in nuts 18. 1, which make it possible to fasten flanges 18. 2, fastening angles or tabs on the outside of the rear wall 11. In a particularly stable embodiment, which is used for example when it comes to particularly large-area antennas, the rear wall 11 can be stiffened by metal strips or other elements inside to better initiate torques and forces in the rear wall 11 can.

In a preferred embodiment of the antenna, the radiating elements 14 have fastening elements at the lower end, which allow the radiating elements 14 to be fastened to the circuit board 13. For this purpose, snap-in mechanisms or plug-in connections can be provided as fastening elements, which make it possible to insert the blasting elements 14 into holes 13. 1 of the circuit board 13 and to latch them there. Instead of a snap connection and screw, solder or other - connections can be provided. Ideal are connections that produce not only a mechanical connection but also an electrically conductive connection.

When connecting the radiating elements 14 to the circuit board 13, it should be noted that the front side of the circuit board 13 may be made metallic to serve as a reflector. The fasteners must be at least partially designed so that they do not form a conductive connection to the conductive side of the circuit board 13. Otherwise, both fasteners would be shorted across the metallic side of the circuit board 13 and the antenna 10 could not be driven.

In the FIGS. 2A and 2B a further inventive antenna 20 is shown. In Fig. 2A shows a section through a part of the antenna 20. The layer structure is described below from bottom to top (respectively from the back to the front). The rear wall 21 has a circumferential side wall which is substantially perpendicular to the surface defined by the x-axis and the y-axis. This surface is also called the xy surface. In Fig. 2A only a part of the left side wall of the rear wall 21 can be seen. Towards the top, the side wall of the rear wall 21 closes with a kind of fold 21.1, as in FIG Fig. 2A indicated. In the Figures 1A . 1B . 2A and 2B this fold is executed as a circumferential fold which is particularly advantageous, but not mandatory. In the region of the fold 21.1, the rear wall 21 is welded or glued to a radome 22. For example, a seam welding method may be used to weld the radome 22 to the rear wall 21. In this welding process, the areas to be welded are heated and connected by ultrasound. The Rear wall 21 forms, together with the radome 22, an antenna housing which encloses the antenna elements. The following antenna elements are in Fig. 2A The foam bed 29 rests on the rear wall 21 and carries on the front side the circuit board 23. Preferably recesses are provided in the foam bed 29 to, for example, the lower ends 24.2 of the supports 24.1 to receive the radiating elements 24. The foam bed 29 may additionally or alternatively comprise recesses for cables, etc. The circuit board 23 has on the back 23.5 a drive circuit or a part of a drive circuit. On the front 23.6, the circuit board 23 is provided over the entire surface with a metal layer. The drive circuit and the metal layer are in Fig. 2A and Fig. 2B not visible. In the area 23.1, the circuit board 23 is provided with holes to receive the lower ends 24.2 of the supports 24.1 of the radiating elements 24. In the region of the lower ends 24.2, for example, connections can be arranged or formed which, in addition to a mechanical connection, also produce an electrically conductive connection.

In the foam core 25 a plurality of recesses 25.1 are provided, of which in Fig. 2A one can be seen in section. The radiating element 24 is seated in this recess 25.1. The foam core 25 fills the area between the front side 23.6 of the circuit board 23 and the rear or inside of the radome 22. Preferably, there is no gap between the top of the foam core 25 and the radome 22. The relatively flexible and thin radome 22 is supported by the foam core 25 substantially over the entire xy surface.

Preferably, the foam core 25 according to the invention has a thickness D1 between 1 cm and 20 cm. The thickness D1 is essentially determined by the height H1 of the three-dimensional radiating elements 24, and by the thickness D2 of the part of the locating core 25 which is located above the radiating elements 24. As in Fig. 2A is shown in the example D1 = H1 + D2. At least the area of the foam core 25 which is located above the radiating elements 24 must be designed RF or HF suitable.

The circuit board 23 typically has a thickness D4 between 50 μm and 2mm. Preferably, the circuit board is 250 μm thick. The radome 22 preferably has a thickness D3 between 0.5 mm and 5 mm, preferably between 1 and 2 mm. The radome 22 and also the circuit board 23 are designed so thin in the preferred embodiments that they do not have in themselves sufficient mechanical stability for an antenna. Only through the novel use in a layered structure, the entire antenna gets sufficient stability.

The drive circuit can be used according to the invention for feeding the radiating elements. For this purpose, the drive circuit may comprise a network which connects feed inputs with the beam elements so that they can be driven with the desired phases.

A group antenna according to the invention is characterized in that a plurality of beam elements are arranged in rows and columns. The radiating elements 24 of the antenna 20 are in the in Fig. 2B shown example rotated by 45 degrees.

In Fig. 2B the top view of the radome 22 of the antenna 20 is shown, wherein the position of the radiating elements 24 is indicated by dashed lines. There are four columns with four radiating elements 24 are provided. Each of the sixteen radiating elements 24 is seated in its own cylindrical recess 25.1 of the foam core 25. In the example shown, the individual radiating elements 24 are driven in such a way that an E-field results for each radiating element 24, which is directed counterparallel to the x-axis. This results in an E-field which is linearly polarized in the negative x-direction (vertical polarization).

The radiating elements can also be controlled differently. Depending on the control, for example, circular, elliptical polarizations, or slant polarizations can be achieved.

A part of a drive circuit 30, according to the invention, is in Fig. 3 shown as an example. The drive circuit 30 is a network which is located on the rear side 23.5 of the circuit board 23 and has two supply inputs 32.1 and 32.2. There are four gates 31.1 to 31.4 provided with the fasteners (in Fig. 3 not visible) of the radiating element 24 are in communication. Between the power input 32.1 and the two ports 31.4 and 31.2 a 180 ° hybrid 33.1 is arranged. Between the power input 32.2 and the two ports 31.3 and 31.1 another 180 ° hybrid 33.2 is arranged. The 180 ° hybrid 33.2 comprises a delay line between the points A and C and a further delay line between the points A and B. The line between B and C in turn represents a delay line. The ports 31.1 to 31.4 are connected to the two 180 ° hybrids 33.1 and 33.2, each causing the same phase shift. The network 30 ensures that the respectively diagonally opposite ports are 180 ° out of phase, that is to say, driven in opposite phase, whereby the other two ports each lie in a virtual short-circuit plane. The power inputs 32.1 and 32.2 thus have a high degree of mutual decoupling. This gives a particularly pure polarization of the radiated wave, or a strongly suppressed cross-polarization component.

Other embodiments of 180 ° power dividers are possible.

If one then feeds the supply input 32.2 with an RF signal S2 (t), then a signal with the phase position 0 ° is present at the port 31.3 and a signal with the phase position 180 ° is present at the port 31.1. With the network 30 shown, it is therefore possible to generate a push-pull signal from an RF signal S2 (t). The beam element builds up a + 45 ° Slant polarization in the described supply. Alternatively, the sole supply of the power input 32.1 generates am Radiation element a -45 ° Slant polarization. (The name of the polarization is valid only if the arrangement according to Fig. 3 is aligned accordingly in the xy direction. In the arrangement according to Fig. 2B are slant and horizontally / vertically "reversed" again).

If one feeds, for example, the supply input 32.1 with an RF signal S1 (t) and the supply input 32.2 with an RF signal S2 (t), which are both in phase with one another, a signal with the phase position 0 ° is present at the gate 31.2 , at the gate 31.3 a signal with the phase position 0 °, at the gate 31.4 a signal with the phase position 180 ° and at the gate 31.1 a signal with the phase position 180 °. With the network 30 shown, it is thus possible to generate an out-of-phase excitation from two RF signals S1 (t) and S2 (t). The radiating element builds up a horizontal polarization in the described feed.

If the supply inputs 32.1 and 32.2 are controlled in antiphase (ie S1 (t) is 180 ° out of phase with respect to S2 (t)), a vertical polarization builds up, such as in FIG Fig. 2B shown.

In order to achieve a circular polarization, the two supply inputs 32.1 and 32.2 are controlled such that S1 (t) is phase-shifted by + 90 ° or -90 ° with respect to S2 (t). In addition, elliptical polarizations can be generated if, at +90 ° or -90 ° phase shift, the amplitude of S1 (t) is different from the amplitude of S2 (t) or / and the phase shift is 0 °, + 90 °, -90 ° and 180 ° deviates.

It is an advantage of the network 30 shown by way of example that the polarization properties of the antenna can be set without changing the radiating element only by suitable control. Depending on the supply to the supply inputs, the polarization of the signals radiated by the radiation element can thus be influenced.

The driving of the beam elements can also be achieved by other supply circuits, for example (combination) networks and Delay lines, done. The supply circuit may be implemented in planar, coaxial or waveguide line technology.

The supply circuit may be arranged to generate from a signal (e.g., S1 (t)) up to four different drive signals for driving the radiating elements.

Details of another antenna 40 are the Fig. 4 refer to. In this figure, only the lower, respectively rear, region of an antenna 40 is shown. It concerns with Fig. 4 a schematic section through the rear wall 41 and a part of a foam bed 49. The rear wall 41 is, in order to guarantee the necessary stability at a reasonable weight, made of two layers 41.6 and 41.3. Between these layers 41.6 and 41.3 are cavities 41.2. In the areas 41.7, the two layers 41.6 and 41.3 are interconnected. Such a connection can be made for example by welding or gluing. In the example shown, only the rear wall 41 is double or multi-layered. It is also possible to pull the double or multi-layer into the area of the vertical side walls.

It is now possible to incorporate or insert a foam core 49 during assembly of the antenna 40 so that it comes to rest directly on the layer 41.3 of the rear wall 41. However, since settling phenomena, shrinkages or displacements can occur within the assembled antenna housing over time, it is advantageous if means are used which can compensate for such changes. In addition, wind loads or other shocks can result in shifts within the antenna housing. For this reason too, additional funds may be needed to help avoid this.

In Fig. 4 is shown a first possible solution, which is particularly advantageous. A gap of thickness A1 is provided between at least one region of the layer 41.3 of the rear wall 41 and the rear side 49.1 of the foam bed 49. Be in the area of this gap Arranged means that exert a certain pressure on the foam bed 49. As in Fig. 4 shown, for example, a spring element 41.4 can be used, which exerts a contact pressure like a kind of leaf or plate spring. The spring element 41.4 is fastened to the rear wall 41 with a blind rivet 41.5 in such a way that it is not visible from the outside. The lower end of the blind rivets 41.5 protrudes into the intermediate space 41.2. The spring element 41.4 itself can be dish-shaped or strip-shaped, with the ends of the strip-shaped design or the "plate edge" of the plate-shaped design pressing against the foam bed 49 in the example shown. But there are also other elements that exert a resilient force and thus ensure the contact pressure on the foam bed 49. In a separate leaf or plate spring element 41.4, as in Fig. 4 Blind rivets are not essential, but can be helpful during assembly. There are other ways to provide leaf or plate spring element.

In the FIGS. 5A and 5B is shown part of another possible solution that is particularly advantageous. In these two figures, the same reference numerals as in Fig. 4 used, even if the solutions differ in details. The rear wall has bellows 42, which are integrated in a composite plate 41.3. Fig. 5B shows a partial view of one of the bellows 42 in plan view.

Preferably, the foam bed 49 may be compacted or coated in the region of the rear side 49.1 in order to be able to better distribute and initiate the contact pressure. This also applies to the foam bed of the other embodiments.

In Fig. 6 another antenna 50 is shown. The antenna housing (comprising a radome, a foam core and a back wall) has an oval shape. It is shown a plan view of the inside of the rear wall 51. The rear wall 51 is, as in Fig. 4 , multi-layered and there is an area 51.7, in which the layers are interconnected. The region 51.7 has an oval shape in plan view and is formed in the form of a groove or depression. In the example shown, four spring elements 51.4 (Spring plates or bellows) provided which are fastened by means of rivets 51.5, screws or other means to the rear wall 51. The spring elements 51.4 can also be glued, welded or pressed. It is advantageous, for example, to provide the rear wall 51 with pins on which the spring elements 51.4 can be pressed. But the spring elements can also be integrated directly into the back plate, as based on the FIGS. 5A and 5B described. A foam bed 59, which in Fig. 6 is indicated by a dashed outline, resting on the spring elements 51.4.

The inventive rear wall of the various embodiments preferably comprises at least one thermoplastically deformed plate (layer), which preferably comprises polypropylene, polyamide or polyetherimide as the material. In a further preferred embodiment, the rear wall comprises a composite material, preferably CFRP, GFRP or KFK.

In order to give the rear wall stability, it is preferably carried out in two or more layers. By joining (welding or gluing) the two or more layers or plates (for example plates 41.3, 41.6), the rear wall is given the required rigidity. One of the plates (for example the plate 41.6) is preferably a plate deformed by deep-drawing. This plate may be made of one or more thermoforming sheets, which are reinforced, for example.

The back wall according to the invention serves in all embodiments as a hard shell, which gives the entire antenna stability by distributing the suspension forces (wind load) and improving the torsional rigidity.

Preferably, according to the various embodiments of the invention, the radome is produced from one or more foils in a mold. The radome itself is thin and hardly warp-resistant. In a particularly preferred embodiment, the radome is water-repellent on the side facing the outside and / or weather-resistant and / or UV-stabilized. This is particularly advantageous because otherwise the radome may become brittle upon permanent UV irradiation. The water repellency is important because water droplets can affect the radiation or reception characteristics of the antenna. This is especially important for antennas that radiate in the Gigaherz range (eg 60 GHz). However, as an important feature of the various radomes, it is considered that they comprise materials which are suitable for RF or HF, at least in the reception or transmission range of the antenna.

For example, the radome comprises Tedlar® (from DuPont) and / or Kynar® (from ATOFINA). The radome may be provided with glass fibers or Kevlar fibers to make it harder (in the sense of shatterproof). It can also be used PPS as thermoforming film. Alternatively, the radome film may also be designed as a multilayer system, for. For example, a combination of Liquid Crystal Polymer (LCP) from DuPont with Tedlar®. In another case, a multi-layer system may serve as a radome consisting of a prefabricated, thin, flat foam body covered with a foil, which is plastically deformed.

In a preferred embodiment, a plastic film, which later serves as a radome, is placed in a mold before the foam core expands. This allows the radome film to be bonded to the foam core. This method can be used in all described embodiments.

It may be advantageous to insert a release film in order to enable a later sorted separation of radome film and foam core.

The inside of the radome may eventually be coated to provide a mechanical bond with the foam core.

Preferably, the outer skin of the radome may be colorized to provide an inconspicuous attachment to a mast or building enable. I am also able to paint the radome if the paint layer is applied thin enough. An optional additional coating can also be applied to improve the hydrophobic properties.

These various variants and modifications of the radome can be used in all described embodiments.

For example, the fold is a circumferential fold (see, for example, Figure 21.1) of the back wall configured to press the circuit board against the foam core during and after assembly.

The fold is preferably designed so that the seam resulting from the closure is only exposed to a tangential shear load.

Preferably, the area of the radome and the area of the back wall which are to be welded together are designed to be material-homogeneous, that is, the two parts consist of the same materials in the contact area.

According to the invention, the foam core should be designed so that it stabilizes the radome and thereby creates a light, torsionally stiff arrangement.

• leicht in grossen Stückzahlen herstellbar,
• kostengünstig,
• geringe Dichte,
• dünnwandig herstellbar,
• form/dimensionsstabil (geringe Schrumpfung bzw. Masshaltigkeit),
• belastbar,
• isolierend,
• feuchtigkeits/wasserabweisend,
• RF oder HF tauglich (d.h. geringe oder keine Dämpfung),
• keine oder nur geringe Abgabe von Feuchtigkeit oder Wasser.

Preferably, the foam core and / or the foam bed comprises a thermoplastic polymer. This thermoplastic polymer is preferably selected from the group consisting of polystyrene and its co-polymers, polyvinyl chloride, polyether-polyurethane, polyester-polyurethane, polypropylenes, polyethylenes or polymethyl methacrylate (PMMA) or polymethacrylimide (PMI), e.g. Rohazell from Röhm, since these materials are particularly suitable because they possess one or more of the following properties:

• easily produced in large quantities,
• cost-effective,
• low density,
• thin-walled,
• dimensionally stable (low shrinkage or dimensional accuracy),
• resilient,
• insulating,
• moisture / water repellent,
• RF or HF capable (ie little or no damping),
• no or little release of moisture or water.

The foam core and / or the foam bed can be formed by extrusion, injection molding, molding, the RIM process (reaction injection molding) or the RRIM process (reinforced reaction injection molding). In the known RIM and RRIM process, the plastic monomers react with their hardener / crosslinker under the influence of temperature.

The foam core may be fiber reinforced, preferably glass fiber reinforced, if it needs to be given additional stability. This is particularly advantageous if only a relatively thin foam core can be used for reasons of space. The foam core may also have a multi-layer structure or a multi-zone structure, depending on the application and embodiment.

In a preferred modification of the various embodiments described so far, the foam core and / or the foam bed has a pressure-resistant surface or a layer is applied which gives the foam a pressure-resistant surface. The foam can also be modified flame-resistant.

The foam core and, if present, the foam bed act as a mechanical spacer of the antenna elements while improving the stiffness of the entire antenna. In addition, they dampen mechanical vibrations.

According to the invention, a metallic shield arrangement can be provided which is completely, partially or not at all connected to a conductive reflector surface 23.6 - for example reflector surface 23.6. The shield arrangement preferably has the same planes of symmetry as the beam element surrounded by it. It may be in one piece or constructed from a corresponding number of individual elements, taking into account the planes of symmetry. A particularly advantageous arrangement consists of a circumferential electrically conductive wall, which ends depending on the desired beam bundling below or above the point farthest from the reflector surface 23.6 point of the beam element 24. The shield assembly may also be used to reduce mutual coupling between adjacent radiating elements in a array antenna. Each of the described embodiments may be modified by a screen arrangement.

However, the radiating elements can also assume any other orientation. In addition, it may be necessary or useful to choose the horizontal distance (distance in the direction of the y-axis) between the individual radiating elements other than the vertical distance (distance in the direction of the x-axis).

Preferably, a housing for a transceiver or the like is placed on the back of the rear wall of the various embodiments. This housing can be supported on the fold (see for example 21.1). The butt edges of the housing can be inserted into the fold. The power electronics can also be located in the housing.

The described and shown antennas are particularly suitable for operation in the gigahertz frequency range, wherein the power inputs are supplied with signals having a center frequency which is greater than 1 GHz. Particularly suitable are the antennas for mobile and other communication systems. The upper frequency limit can be about 60 GHz. However, the invention is not limited to use in these frequency ranges.

The antenna housing according to the invention can take any arbitrary, flat 3-dimensional form as long as sufficient stability is ensured. In the FIGS. 1A to 4 rectangular or square shapes are shown. As in Fig. 6 For example, the shape may also be oval.

Due to the layered construction and the materials used, the described antennas and especially the array antennas are very compact and lightweight. They are relatively simple and easy to produce, are extremely stable and are suitable for use in difficult environments.

The various elements of the individual embodiments can be combined as needed.

Claims (20)

1. An array antenna (10; 20; 30; 40; 50) with an antenna housing with

   - a wall (11; 21; 41; 51) which comprises a connection region and is configured as a carrier for different elements,

   - a foam core (15; 25), and with

   - a radome (12; 22) which is connected in the manner of a cover with the connection region of the wall (11; 21; 41; 51) in order to thus form an antenna housing together with the wall (11; 21; 41; 51) for the foam core (15; 25) and the following antenna elements a) and b), such that said antenna elements are housed in a protected way:

   a) several individual three-dimensional radiating elements (14; 24), and

   b) at least one circuit board (13; 23) for driving and carrying the individual radiating elements (14; 24),

   characterized in that

   - the wall (11; 21; 41; 51) consists of composite materials and is provided with fastening means in order to fasten the antenna housing to a mast or building,

   - the radome (12; 22) is a thin flexible hard RF- or HF-suitable shell,

   - the foam core (15; 25) is provided with recesses (15.1; 25.1) which are each designed for receiving the three-dimensional radiating elements (14; 24),

   - the foam core (15; 25) is RF- or HF-suitable, and the radome (12; 22) is supported by the foam core (15; 25) over the entire surface area and the foam core (15; 25) is designed in such a way that it stabilizes the radome (12; 22), and

   - that the three-dimensional radiating elements are designed as dipole antennas.
2. Array antenna (10; 20; 30; 40; 50) according to claim 1, characterized in that the wall (11; 21; 41; 51) comprises at least one thermoplastic plate which preferably comprises polypropylene or polyamide.
3. Array antenna (10; 20; 30; 40; 50) according to claim 1 or 2, characterized in that the wall (11; 21; 41; 51) comprises a reinforcing material.
4. Array antenna (10; 20; 30; 40; 50) according to claim 1, 2 or 3, characterized in that the wall (11; 21; 41; 51) comprises press-in nuts (18.1) or other fastening means which are mechanically anchored in the wall (11; 21; 41; 51) in order to introduce forces of a suspension (18.2) into the wall.
5. Array antenna (10; 20; 30; 40; 50) according to claim 1, 2 or 3, characterized in that electric connecting means (16), preferably flange connectors, are provided which allow connecting lines from outside with the antenna housing and producing in the interior of the antenna housing a connecting to a control circuit and/or the radiating elements (14, 24).
6. Array antenna (10; 20; 30; 40; 50) according to claim 1, 3, 4 or 5, characterized in that the connecting region is a circumferential connecting region (11.1; 21.1) and the wall (11; 21; 41; 51) comprises a thermoplastic material at least in the circumferential connecting region (11.1; 21.1) in order to enable the welding, riveting or gluing of the radome (12; 22) with the wall (11; 21; 41; 51).
7. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that the radome (12; 22) comprises one or several foils.
8. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims 1 to 7, characterized in that the radome (12; 22) is water-repellent and/or UV-stabilized on the side of the antenna housing facing to the outside.
9. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that the radome (12; 22) comprises Tedlar® and/or Kynar®.
10. Array antenna (10; 20; 30; 40; 50) (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that the radome (12; 22) has a thickness (D3) of between 0.5 mm and 5 mm, preferably between 1 mm and 2 mm.
11. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that the foam core (15; 25) comprises a thermoplastic polymer, with the thermoplastic polymer being chosen preferably from the group of polystyrene and its co-polymers, polyvinyl chloride, polyetherpolyurethane, polyester-polyurethane, polypropylene, polyethylene, polymethyl methacrylate (PMMA) or polymethacrylimide (PMI).
12. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that the foam core (15; 25) comprises fiber reinforcements, preferably glass-fiber reinforcements.
13. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that the foam core (15; 25) has a multi-layer structure or a multi-zone structure.
14. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that the foam core (15; 25) has a pressure-proof surface and/or is modified to be non-flammable.
15. Array antenna (10; 20; 30; 40; 50) according to claim 1, characterized in that the three-dimensional radiating elements are radiating elements made of metal or plastic radiating elements whose surface has a metallization.
16. Array antenna (10; 20; 30; 40; 50) according to claim 15, characterized in that the three-dimensional radiating elements are placed into a control circuit on the circuit board (13; 23) and are fastened there mechanically and electrically.
17. Array antenna (10; 20; 30; 40; 50) according to claim 16, characterized in that the control circuit comprises the radiating elements (14; 24) and the connecting regions (13.1) for receiving the radiating elements (14; 24) and for producing electrically conductive connections of the radiating elements (14; 24) with the control circuit.
18. Array antenna (10; 20; 30; 40; 50) according to claim 17, characterized in that it comprises a further circuit board (13.2) which is connected mechanically and electrically by means of pin-and-socket connectors (13.3) with the circuit board (13.1), with the further circuit board (13.2) preferably comprising a calibrating power unit or parts of a control circuit.
19. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that it comprises a foambed (17.1, 17.2; 29; 49; 59) which is placed in the wall (11; 21; 41; 51) and comprises a substantially bearing surface for the circuit board (13; 23), with the foambed (17.1, 17.2; 29; 49; 59) preferably comprising recesses (17.3) for leads which are connected with the circuit board (13).
20. Array antenna (10; 20; 30; 40; 50) according to one of the preceding claims, characterized in that it comprises at least one spring element (41.4; 51.4) in order to exert a pressing pressure on one or several of the antenna elements.

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