EP3430679B1 - Protective antenna cover for vehicles - Google Patents

Description

The invention relates to a shell-shaped antenna protection hood (ESD hood) designed as a ring line radiator, in particular made of dielectric plastic, for the reception of circularly polarized satellite radio signals.

In the example of SDARS satellite broadcasting, such reception occurs at a frequency of approximately 2.33 GHz with the free space wavelength λ = 12.8 cm in two adjacent frequency bands, each with a bandwidth of 4 MHz with a spacing of the center frequencies of 8 MHz. The signals are emitted from different satellites with an electromagnetic wave that is circularly polarized in one direction. Similar satellite broadcast systems are currently being planned. Accordingly, circularly polarized antennas in the corresponding direction of rotation are used for reception. The satellites of the Global Positioning System (GPS) also emit circularly polarized waves in one direction at a frequency of around 1575 MHz, so that the antenna shapes mentioned can also be designed for this service.

For mobile reception of circularly polarized satellite signals from the satellite broadcasting services SDARS or XM or e.g. the GPS navigation system on vehicles, such antennas are preferably used on the vehicle roof. The metallic vehicle roof often serves as an extended electrically conductive base for such antennas. There is also provision for an antenna for receiving circularly polarized satellite radio signals to be accommodated under a dish-shaped antenna protection hood made of dielectric plastic. Here, the shell opening side is covered with an electrically conductive base plate that is mechanically connected to the antenna protective hood and can be positioned on the outer skin of a motor vehicle in an essentially horizontally oriented manner.

Such a ring line radiator is known from DE 10 2009 040 910 and in Fig. 1 presented as prior art. The ring line radiator shown is cut from sheet metal and then bent into the shape shown. The arrangement of such an antenna under a bowl-shaped antenna protection hood made of plastic material is known from DE 10 2013 005 001 . The bowl-shaped antenna protection hood serves to protect the antenna from moisture as well as from electrostatic discharge (ESD protection). The satellite antenna described there is designed in the shape of a ring and is attached to the base plate which closes the opening of the protective antenna cover. A similar type of fastening on the base plate is common when using patch antennas as circularly polarized satellite antennas. Furthermore, from the WO 2010/114336 A2 the arrangement of a vehicle antenna on the surface of an antenna hood is known. The EP 2 424 036 A2 shows a further known loop antenna for receiving circularly polarized satellite radio signals.

In the Fig. 1 The known satellite antenna shown comprises a ring line radiator 1 formed by a closed ring line 3, which is arranged in particular at a distance h <λ / 10 and running parallel to a conductive base plate 6, with a ring line radiator 1 distributed around the circumference of the ring line radiator 1 and connected to the conductive base plate 6 extending, linear, substantially vertical radiators 4a-4d. Here at least one of the linear radiators is connected at its lower end via a capacitance 5a-5c to the electrically conductive base plate 6 and another essentially vertical radiator 4d is connected to an antenna connection 5e via a capacitance 5d.

In addition to the functionality of the antenna, the economic outlay associated with both the manufacture of the antenna and its implementation on the vehicle is decisive for the acceptance of the technology of an antenna for vehicles.

Due to the very tightly tolerated radiation directional diagrams of satellite antennas, the tolerances for manufacturing such antennas are extremely small. Likewise, in the case of circularly polarized antennas which work according to a different operating principle, such as patch antennas, for example, compliance not only with the mechanical dimensions but also the dielectric properties of the antenna body is a problem. With the present ring line radiator, it is particularly important to maintain the mechanical dimensions. The storage of the ring line radiator cut from sheet metal and then bent as a bulk product in series production is also problematic. A shape-retaining storage of the sheet metal structure is extremely complex and a damaging deformation of the structure due to the handling due to the extremely narrow tolerances is very difficult to avoid. Naturally, these demands on accuracy lead to increased manufacturing costs for the antennas.

The present invention is therefore associated with the task of designing an antenna for receiving circularly polarized satellite radio signals which, with little economic outlay, enables simpler implementation on the vehicle with high functional reliability.

This object is achieved by the features of claim 1.

Advantageous embodiments of the invention are described in the subclaims and the description.

The antenna protective hood can be positioned over an electrically conductive base plate that is mechanically connected to it, covers the opening of the antenna protective hood and is to be positioned on an outer skin of a motor vehicle in an essentially horizontally oriented manner. The opening of the antenna protective hood can also be closed with an in particular dielectric film or plate, which is in particular positioned in the reference plane.

The antenna protection hood can be provided with at least one ring line radiator, formed by a closed ring line running parallel to the conductive base plate at a distance h, with linear, substantially vertical radiators distributed around the circumference of the ring line and running towards the conductive base plate. Here, a linear radiator or a vertical radiator is understood according to the invention to be a linear radiator connected to the ring line, which does not necessarily extend at an angle of 90 ° from the plane of the ring line. Rather, the vertical radiators according to the invention can also extend at an angle different from 90 ° in the direction of the electrically conductive base plate or in the direction of the reference plane formed by the opening of the protective antenna hood. A linear radiator according to the invention also does not necessarily have to have the shape of a straight line. Rather, the term linear radiator is seen according to the invention as a distinction to the ring radiator, which forms a closed (round or angular) ring shape. In contrast, the linear radiators according to the invention extend away from the ring line in the direction of the opening of the protective antenna hood. It is therefore understood that the linear Radiators can also be curved if the antenna protective hood has, for example, a dome-shaped design.

The antenna protection hood can in principle be designed as desired, for example shell-shaped, dome-shaped or pyramid-shaped or as a combination of these shapes. Preferably, however, the antenna protective hood has partial surfaces on its inside which are coated in an electrically conductive manner and whose shape is adapted to the function of the components of the ring line radiator.

At least one of the linear radiators can be capacitively connected at its lower end to the electrically conductive base plate via a capacitance and another linear radiator can be capacitively connected to an antenna connection via a capacitance.

• Auf der Innenfläche der Antennenschutzhaube 1a ist der Ringleitungsstrahler 1, bestehend aus der Ringleitung 3 sowie aus den an diese angeschlossenen und zur leitenden Grundplatte 6 hin verlaufenden linearen bzw. vertikalen Strahlern 4, 4a-d als elektrisch leitend zusammenhängende Antennenstruktur beschichtet aufgebracht.
• Die Kontur der Innenfläche der schalenförmigen Antennenschutzhaube 1a ist durch Formgebung ihrer Innenfläche für die Gestaltung der elektrisch leitenden Flächen bzw. streifenförmigen Leiterbahnen 12 in der Weise gestaltet, dass die geschlossene Ringleitung als eine auf einer zur leitenden Grundfläche 6 parallelen, elektrisch leitend beschichteten Fläche verläuft und die zur leitenden Grundfläche 6 im Wesentlichen vertikalen Strahler 4, 4a-d auf im wesentlich vertikalen, elektrisch leitend beschichteten Flächen ausgebildet sind.

Individual features of the invention can be:

• The ring line radiator 1, consisting of the ring line 3 and the linear or vertical radiators 4, 4a-d connected to it and extending towards the conductive base plate 6, is applied as an electrically conductive cohesive antenna structure coated on the inner surface of the antenna protective hood 1a.
• The contour of the inner surface of the shell-shaped antenna protection hood 1a is designed by shaping its inner surface for the design of the electrically conductive surfaces or strip-shaped conductor tracks 12 in such a way that the closed ring line runs as an electrically conductive coated surface parallel to the conductive base surface 6 and the radiators 4, 4a-d which are essentially vertical to the conductive base area 6 are formed on essentially vertical, electrically conductive coated surfaces.

A particular advantage of the invention is given by the fact that the dimensional accuracy can easily be maintained due to the form of the antenna protective hood 1a pressed in plastic. Modern plastics are long-term stable in their properties even under extreme weather conditions. The conductive applied with modern laser technologies or imprinting techniques on the inner surfaces of the corresponding pre-formed, shell-shaped antenna protection hood 1a Surfaces therefore have constant electrical properties over the long term. Laser or printing techniques have already proven suitable for mass production. The electrically conductive layer can be imprinted, for example, by a pressure pen for the direct application of the conductive layer or, for example, by a laser beam. The tip of the pressure pen or the diameter of the laser beam determines the fine grain of the print and thus the fineness of the structures to be designed.

When using a laser, the inner surface of the antenna protection hood can be covered over a large area with an electrically conductive layer and above it with a laser-sensitive layer, which cures when exposed to laser light in such a way that the electrically conductive layer underneath is retained and the unexposed layer in a subsequent etching process Places of the conductive layer are removed.

Finally, if an electrically conductive layer is present over a large area, it is possible to treat it with a high-energy laser beam in such a way that the non-conductive surface parts are "lasered free" from the layer.

The necessary firm form fit between the antenna protective hood 1a and the conductive base surface 6 can always be established. The complexity in the production of known ring line radiators 1 cut from sheet metal, then bent, correctly mounted and correctly mounted on the conductive base surface 6 is extremely reduced in the case of a ring line radiator according to the invention.

The capacitances 5a, 5b, 5c, 5d can each be formed in pairs opposite one another by a flat electrode 5a, 5b, 5c, 5d and a flat counter-electrode parallel thereto. In each case, a flat electrode 5d, which is connected to the lower end of the relevant, essentially vertical radiator 4d, is applied as an electrically conductive flat structure on an expression of the inner surface of the protective antenna hood 1 running parallel at a distance 11 from the conductive base plate 6. The capacitance value of the capacities is determined by the distance 11.

In a ring line radiator 1 according to the prior art in Fig. 1 Compliance with the capacitance values by the electrodes 5a, 5b, 5c, 5d is of great importance with regard to the antenna impedance and the radiation diagram. In the case of the invention, the necessary securing of the correct distance 11 (see Figure 2c ) of the electrodes 5a, 5b, 5c, 5d from the conductive base 6 or from the counter-electrode forming the antenna connection 5 is given in a simple manner by the dimensional accuracy of the antenna protective hood 1a. With modern methods, the coating of the correspondingly shaped inside of the protective antenna hood 1a can be done extremely time-effectively and the production of the satellite antenna by attaching the protective antenna hood 1a to the electrically conductive base 6 can be done in a few simple steps. It is precisely here that a great advantage of the present invention becomes apparent.

For the capacitive connection of the at least one of the essentially vertical radiators 4, 4a-d at its lower end to the antenna connection 5 in the plane of the base plate 6, a flat counter-electrode 5e electrically insulated from this is formed, which is connected to the antenna connection 5.

The edge line of the opening of the bowl-shaped antenna protection hood 1a and the conductive base surface 6 run in a plane which is used as reference plane 16 for the following description in a horizontal position ( Fig. 4 ) is defined. The antenna protective hood 1 a thus extends above this reference plane 16.

To ensure error-free removal from the mold when the shell-shaped hood is pressed, all surface parts lying inside the shell-shaped antenna protective hood 1 and all surface parts lying on the outer surface of the dish-shaped antenna protective hood 1 can assume an angle of no more than 89.5 ° as a draft angle to the horizontal reference plane 16.

In a manufacturing process, all surfaces to be coated in an electrically conductive manner can be coated with the aid of a needle-shaped beam producing the coating from only one direction (= processing direction 17) which runs essentially perpendicular to the reference plane 16. All of the surfaces to be coated in the interior of the shell-shaped antenna protection hood can have a so-called processing direction 17 Take a coating angle 19 of at least 5 ° to ensure a sharply contoured coating.

Furthermore, in a manufacturing process, the electrically conductive coated surfaces of horizontal parts of the ring line radiator, and optionally also the capacitance electrodes, can each lie parallel to the reference plane 16 and essentially perpendicular to the processing direction 17. The surfaces of the essentially vertical radiators that are to be coated in an electrically conductive manner can assume a coating angle 19 of at least 5 °, in particular more than 45 °, with respect to the machining direction 17, in order to ensure a sharply contoured coating.

Furthermore, the dish-shaped antenna protection hood 1a can have the shape of a stepped pyramid hollowed out from below, the lower side walls of which rest on the electrically conductive base area, the hood parallel to this base area having two substantially horizontal partial areas located above it in the form of a first circumferential step and one above it has lying, substantially flat roof surface.

According to the invention, four capacitance electrodes can be located on the underside of a horizontal partial surface of a circumferential step, each in four corners.

In an advantageous embodiment of the invention, the ring line 3 can be located on the underside of an upper roof surface, in particular following the contour of this roof surface.

The four capacitance electrodes 5a, 5b, 5c, 5d can each be connected to an overlying corner of the ring line 3 via an essentially vertical radiator 4, 4a-d.

In an advantageous embodiment of the invention, the particularly shell-shaped antenna protection hood 1a can be constructed in the form of a truncated pyramid hollowed out from below, which comprises four side walls and a roof surface, these side walls resting on the electrically conductive base surface and the ring line 3 being on the underside of the Roof area is located in the course of the contour of this roof area following.

In an advantageous embodiment of the invention, the ring line 3 can be connected at each of its four corners to an essentially vertical radiator 4, 4a-d, which, starting from the relevant corner, leads along the inner edge between side walls adjacent to the corner, until it ends at a distance 11 from the base 6.

The vertical radiators 4, 4a-d can each be connected at a distance 11 from the base area with a capacitance electrode 5a, 5b, 5c, 5d, which is embodied by embossing at the respective corner in the form of a horizontal area running at a distance 11 parallel to the base area 6 which is created by grading the inside of the side walls.

The surfaces to be coated in an electrically conductive manner can be constructed in the form of electrically conductive grid structures, the mesh size of which is, in particular, essentially less than 1/8 of the wavelength.

• Fig. 1.
  Ringleitungsstrahler 1 nach dem Stand der Technik mit vertikalen Strahlern 4, 4a-d und Kapazitäten 5a - d an deren unteren Enden, z.B. als Blechstruktur mit Halterung auf Kunststoffstützen.
• Fig. 2.
  1. a) Ringleitungsstrahler als elektrisch leitende Beschichtung auf der Innenfläche einer schalenförmigen Antennenschutzhaube 1a aus einem dielektrischen Kunststoff nach der Erfindung. Die Schrägansicht auf den Innenraum der Antennenschutzhaube 1a zeigt die beschichteten Flächen als Netzstrukturen. Die Berandung auf der Unterseite der Antennenschutzhaube 1a (schraffiert) verläuft in einer Ebene (Bezugsebene 16) zur Verbindung mit der elektrisch leitenden Grundfläche 6 bei der Endmontage. Die Ringleitung 3 und die Elektroden 5a -d der Kapazitäten an den unteren Enden der im wesentlichen vertikalen Strahler 4a -d sind auf horizontalen Flächenteilen der entsprechend geformten Antennenschutzhaube 1a als leitende Beschichtung aufgebracht.
  2. b) Ringleitungsstrahler als elektrisch leitende Beschichtung auf der Innenfläche einer schalenförmigen Antennenschutzhaube 1a wie in a) jedoch mit Sicht auf den Innenraum von unten. Die strichpunktierte Schnittlinie Q beschreibt die Sicht auf den in Fig. 1c) dargestellten Querschnitt Q der Anordnung.
  3. c) Die Querschnittszeichnung zeigt den Abstand 11 zwischen den Kapazitätselektroden 5a, 5b, 5c, 5d und der elektrisch leitenden Grundfläche 6 bzw. der Gegenelektrode zur Bildung des Antennenanschlusses 5e. Die Einhaltung der geforderten Kapazitätswerte mithilfe der Konstanz dieses Abstands 11 ist durch die maßhaltige Form der Antennenschutzhaube 1a sowie deren zeitliche Beständigkeit gegeben. Der Neigungswinkel α der im Wesentlichen vertikalen Innenflächen der Antennenschutzhaube 1 gegenüber der zur leitenden Grundfläche 6 senkrechten Linie kann mindestens 5° betragen und sollte bei einer zu letzterer parallelen Bearbeitungsrichtung 17 den Beschichtungswinkel 19 (Fig.4) nicht unterschreiten.
• Fig. 3
  Explosionszeichnung zur Darstellung des fiktiv von der Antennenschutzhaube 1a losgelösten Ringleitungsstrahlers mit der Ringleitung 3 und den vertikalen Strahlern 4 als elektrisch leitende Flächen (Gitternetz) über einer als elektrisch leitend beschichtete Leiterplatte 2 dargestellten elektrisch leitenden Grundfläche 6. Die Kapazitätselektrode 5d ist über die als Gegenelektrode gebildete isolierte leitende Fläche auf der beschichteten Leiterplatte, welche den Antennenanschluss 5e bildet, kapazitiv an diesen angekoppelt.
• Fig. 4
  Antennenschutzhaube 1a mit elektrisch leitender Beschichtung als Ringleitungsantenne nach der Erfindung mit Sicht von schräg unten in die Öffnung der Antennenschutzhaube. Die Antennenschutzhaube ist in Form einer von unten ausgehöhlten stumpfen und insbesondere gestuften Pyramide gestaltet. Hierbei ist darauf geachtet, dass diese Form in einfacher Kunststoff-Spritzgusstechnik herstellbar ist. Die als Gitternetz gekennzeichneten Flächen zeigen die Elemente des Ringleitungsstrahler in dieser Projektion. Die Schalenränder verlaufen in der oben genannten Bezugsebene 16. Für den insbesondere punktförmig durchzuführenden Aufdruck einer elektrisch leitenden Schicht kann eine lang gestreckte Beschichtungseinrichtung 18 vorhanden sein, welche beispielhaft als ein Druckstift zum unmittelbaren Aufdrucken der leitenden Schicht oder zum Beispiel auch als Laserstrahl realisiert sein kann. Die Spitze des Druckstifts bzw. der Durchmesser des Laserstrahls bestimmt jeweils die Feinkörnigkeit des Drucks und damit die Feinheit der zu gestaltenden Strukturen. Die Beschichtungseinrichtung 18 ist in der Bearbeitungsrichtung 17 ausgerichtet. Der Beschichtungswinkel 17 zwischen dieser Richtung 17 und der zu bedruckenden Fläche ist zur Sicherstellung einer scharf konturierten Beschichtung mindestens 5° gewählt.
• Fig. 5
  1. a) Sicht von unten in die Öffnung der Antennenschutzhaube 1a mit elektrisch leitender Beschichtung als Ringleitungsstrahler gemäß Fig. 4. Die strichpunktierten Linien Q1 bis Q5 zeigen die Schnittlinie für die Darstellung der entsprechenden Querschnitte in den nachfolgenden Figuren b) bis e).
  2. b) Die Darstellung des Querschnitts gemäß der Schnittlinie Q1 zeigt die steilen Seitenwände der Pyramide, die beispielsweise unter einem Winkel von kleiner 90° und größer 75° zur Bezugsebene 16 verlaufen. In dieser Position sind die Kapazitätselektroden 5b (links unten) und 5c (rechts unten) sowie die Gegenelektroden, welche durch die elektrisch leitende Grundfläche 6 einerseits und durch den Antennenanschluss 5e andererseits gebildet sind, dargestellt.
  3. c) Darstellung des Querschnitts gemäß der Schnittlinie Q2 analog zu b). Die Kapazitätselektroden sind hier nicht betroffen
  4. d) Darstellung des Querschnitts gemäß der Schnittlinie Q3. Die vertikalen Strahler 4, 4a-d sind unter einem Winkel α gegen die zur Grundfläche 6 senkrechte Bezugslinie geneigt, der zwischen 0° und 70° betragen kann.
  5. e) Darstellung des Querschnitts gemäß der Schnittlinie Q4
  6. f) Darstellung des Querschnitts gemäß der Schnittlinie Q5.
• Fig. 6
  Beispielhafte Ausführung von zwei Ringleitungen 3 und 3' mit gemeinsamem Zentrum, aufgebracht auf die Antennenschutzhaube 1a, welche ähnlich wie in den Fig. 4 und 5 als eine von unten ausgehöhlte stumpfe Pyramide gestaltet ist. Die Darstellung zeigt in einer vorteilhaften Ausgestaltung der Erfindung die Sicht auf die Antennenschutzhaube 1a von unten mit den durch Gitternetz gekennzeichneten aufgebrachten elektrisch leitenden Flächen sowohl des inneren als auch des äußeren Ringleitungsstrahlers 3,3'. Beide Ringleitungsstrahler können z. B. jeweils durch geeignete Dimensionierung der Ringleitung 3 bzw. 3' und der Kapazitäten für die gleiche Frequenz für den kombinierten Einsatz bei Antennen-Diversity-Technologien gestaltet sein. Hierbei wird der innere Ringleitungsstrahler als Strahler 1. Ordnung, d.h. für eine azimutale Phasenverteilung von 2π über einen Umlauf und der äußere Ringleitungsstrahler als Strahler 2. Ordnung, d.h. für eine azimutale Phasenverteilung von 2*2π über einen Umlauf gestaltet. Ebenso kann in einer vorteilhaften Ausgestaltung der Erfindung der äußere Ringleitungsstrahler für den Empfang eines weiteren Satelliten-Funkdienstes bei einer niedrigeren Frequenz als der des inneren Ringleitungsstrahlers mit nur vier vertikalen Strahlern 4' ausgestattet werden.
• Fig. 7
  In einer weiteren vorteilhaften Ausgestaltung der Erfindung ist der Ringleitungsstrahler mit einer terrestrischen Breitband-Kommunikationsantenne 15, zum Beispiel für die LTE- Kommunikation und mit einer terrestrischen Empfangsantenne 14, zum Beispiel für den AM/FM/DAB-Rundfunkempfang, kombiniert. Der besondere Vorteil der dargestellten Kombination besteht in der vollständigen elektromagnetischen Entkopplung der terrestrischen Antennen von dem Ringleitungsstrahler 1 für Satellitenempfang.
  1. a) Aus der Sicht auf die Antennenschutzhaube 1a in Fig. 7a von schräg unten geht die vorteilhafte Kombinierbarkeit der terrestrischen Antennen mit einem gemeinsamen terrestrischen Antennen-Anschluss 13 im Zentrum des Ringleitungsstrahlers hervor. Die terrestrische Breitband-Kommunikationsantenne 15 ist im Wesentlichen aus an der terrestrischen Antennen-Anschlussstelle 13 zusammenlaufenden streifenförmigen elektrisch leitenden Leiterbahnen 12 gebildet, welche auf V- förmig auf der Antennenschutzhaube 1a ausgebildeten Flächen eingelasert bzw. gedruckt sind. Auf ähnliche Weise ist die terrestrische Empfangsantenne 14 durch streifenförmige aufgedruckte bzw. eingelaserte elektrisch leitende Leiterbahnen 12 mit der gemeinsamen Antennen-Anschlussstelle 13 gestaltet.
  2. b) zeigt diese Anordnung mit Sicht von unten, woraus die Kombination der terrestrischen Empfangsantenne 14 - an deren oberen Ende eine Dachkapazität 16 ausgebildet ist - mit der Breitband-Kommunikationsantenne 15 ersichtlich ist.
• Fig. 8
  Für die Anwendung derartiger Antennen auf dem Fahrzeugdach kommen Antennenschutzhauben 1a zur Anwendung, deren Breite quer zur Fahrtrichtung aus strömungstechnischen Gründen kleiner ist als längs zur Fahrtrichtung.
  1. a) Darstellung der beispielhaften Gestaltung des Querschnitts einer Antennenschutzhaube 1a nach der Erfindung (quer zur Fahrtrichtung) mit den für den Ringleitungsstrahler und der terrestrischen Breitband-Kommunikationsantenne 15 elektrisch leitend mit streifenförmigen Leiterbahnen 12 beschichteten Flächen. Diese Leiterbahnen sind insbesondere V- förmig in der Ebene quer zur Fahrtrichtung ausgewinkelt. Zur qualitativ hochwertigen Beschichtung der Antennenschutzhaube 1a von unten aus Richtung der senkrechten gestrichelten Linie ist es vorteilhaft, den Beschichtungswinkel 19 von a=5° zwischen dieser Linie und der zu beschichtenden Fläche an keiner Stelle zu unterschreiten.
  2. b) in der Darstellung eines Schnittes der Antennenschutzhaube 1a nach der Erfindung längs der Fahrtrichtung sind die streifenförmigen Leiterbahnen 12 der im Vergleich zur Breitband-Kommunikationsantenne 15 höheren terrestrischen Empfangsantenne 14 dargestellt. Diese Leiterbahnen 12 sind im Gegensatz zu denen der Breitband-Kommunikationsantenne 15 in der Ebene längs der Fahrtrichtung V-förmig ausgewinkelt. Beide Antennen treffen sich in der gemeinsamen terrestrischen Antennen-Anschlussstelle 13.

The invention is explained in more detail below on the basis of exemplary embodiments. The corresponding figures show in detail:

• Fig. 1 .
  Ring line radiator 1 according to the prior art with vertical radiators 4, 4a-d and capacitors 5a-d at their lower ends, for example as a sheet metal structure with a holder on plastic supports.
• Fig. 2 .
  1. a) Ring line radiator as an electrically conductive coating on the inner surface of a bowl-shaped antenna protection hood 1a made of a dielectric plastic according to the invention. The oblique view of the interior of the protective antenna hood 1a shows the coated surfaces as network structures. The border on the underside of the protective antenna hood 1a (hatched) runs in a plane (reference plane 16) for connection to the electrically conductive base surface 6 during final assembly. The ring line 3 and the electrodes 5a-d of the capacitances at the lower ends of the essentially vertical radiators 4a-d are applied as a conductive coating to horizontal surface parts of the correspondingly shaped protective antenna hood 1a.
  2. b) Ring line radiator as an electrically conductive coating on the inner surface of a bowl-shaped antenna protection hood 1a as in a) but with a view of the interior from below. The dash-dotted line Q describes the view of the in Figure 1c ) shown cross section Q of the arrangement.
  3. c) The cross-sectional drawing shows the distance 11 between the capacitance electrodes 5a, 5b, 5c, 5d and the electrically conductive base area 6 or the counter-electrode for forming the antenna connection 5e. Compliance with the required capacitance values with the help of the constancy of this distance 11 is given by the dimensionally stable shape of the antenna protective hood 1a and its stability over time. The angle of inclination α of the essentially vertical inner surfaces of the protective antenna hood 1 with respect to the line perpendicular to the conductive base surface 6 can be at least 5 ° and should, in the case of a processing direction 17 parallel to the latter, the coating angle 19 ( Fig. 4 ) do not fall below.
• Fig. 3
  Exploded view to show the ring line radiator fictitiously detached from the antenna protection hood 1a with the ring line 3 and the vertical radiators 4 as electrically conductive surfaces (grid) over an electrically conductive base surface 6 shown as an electrically conductive coated circuit board 2 isolated conductive surface on the coated circuit board, which forms the antenna connection 5e, capacitively coupled to the latter.
• Fig. 4
  Antenna protection hood 1a with an electrically conductive coating as a ring line antenna according to the invention with an oblique view from below into the opening of the antenna protection hood. The antenna protection hood is designed in the form of a truncated and, in particular, stepped pyramid hollowed out from below. Care is taken to ensure that this shape can be produced using a simple plastic injection molding technique. The areas marked as a grid show the elements of the ring line radiator in this projection. The shell edges run in the above-mentioned reference plane 16. For the printing of an electrically conductive layer, which is in particular punctiform, an elongated coating device 18 can be present, which can be used, for example, as a printing pin for directly printing the conductive layer or, for example, as Laser beam can be realized. The tip of the pressure pen or the diameter of the laser beam determines the fine grain of the print and thus the fineness of the structures to be designed. The coating device 18 is aligned in the machining direction 17. The coating angle 17 between this direction 17 and the surface to be printed is selected at least 5 ° to ensure a sharply contoured coating.
• Fig. 5
  1. a) View from below into the opening of the protective antenna hood 1a with an electrically conductive coating as a ring line radiator according to FIG Fig. 4 . The dash-dotted lines Q1 to Q5 show the cutting line for the representation of the corresponding cross-sections in the following figures b) to e).
  2. b) The illustration of the cross-section along the section line Q1 shows the steep side walls of the pyramid, which for example run at an angle of less than 90 ° and greater than 75 ° to the reference plane 16. In this position, the capacitance electrodes 5b (bottom left) and 5c (bottom right) and the counter-electrodes, which are formed by the electrically conductive base surface 6 on the one hand and by the antenna connection 5e on the other, are shown.
  3. c) Representation of the cross section according to the section line Q2 analogous to b). The capacitance electrodes are not affected here
  4. d) Representation of the cross section according to the section line Q3. The vertical radiators 4, 4a-d are inclined at an angle α to the reference line perpendicular to the base 6, which can be between 0 ° and 70 °.
  5. e) Representation of the cross section according to the section line Q4
  6. f) Representation of the cross-section according to the section line Q5.
• Fig. 6
  Exemplary embodiment of two ring lines 3 and 3 'with a common center, applied to the antenna protective hood 1a, which is similar to that in FIGS Fig. 4 and 5 is designed as a truncated pyramid hollowed out from below. In an advantageous embodiment of the invention, the illustration shows the view of the protective antenna hood 1 a from below with the electrically conductive surfaces of both the inner and the inner surface marked by a grid outer ring line radiator 3,3 '. Both ring line radiators can, for. B. each be designed by suitable dimensioning of the ring line 3 or 3 'and the capacities for the same frequency for combined use in antenna diversity technologies. The inner ring line radiator is designed as a 1st order radiator, ie for an azimuthal phase distribution of 2π over one revolution and the outer ring line radiator as a 2nd order radiator, ie for an azimuthal phase distribution of 2 * 2π over one revolution. Likewise, in an advantageous embodiment of the invention, the outer ring line radiator can be equipped with only four vertical radiators 4 'for receiving a further satellite radio service at a lower frequency than that of the inner ring line radiator.
• Fig. 7
  In a further advantageous embodiment of the invention, the loop radiator is combined with a terrestrial broadband communication antenna 15, for example for LTE communication and with a terrestrial receiving antenna 14, for example for AM / FM / DAB radio reception. The particular advantage of the combination shown is the complete electromagnetic decoupling of the terrestrial antennae from the loop radiator 1 for satellite reception.
  1. a) From the view of the protective antenna hood 1a in Figure 7a The advantageous combinability of the terrestrial antennas with a common terrestrial antenna connection 13 in the center of the loop radiator can be seen obliquely from below. The terrestrial broadband communication antenna 15 is essentially formed from strip-shaped, electrically conductive conductor tracks 12 converging at the terrestrial antenna connection point 13, which are lasered or printed onto V-shaped surfaces on the protective antenna hood 1a. The terrestrial receiving antenna 14 is designed in a similar manner by means of strip-shaped printed or laser-etched electrically conductive conductor tracks 12 with the common antenna connection point 13.
  2. b) shows this arrangement with a view from below, from which the combination of terrestrial receiving antenna 14 - at the upper end of which a roof capacity 16 is formed - with the broadband communication antenna 15 can be seen.
• Fig. 8
  For the use of such antennas on the vehicle roof, antenna protective hoods 1a are used, the width of which is smaller transversely to the direction of travel for reasons of flow technology than along to the direction of travel.
  1. a) Representation of the exemplary design of the cross section of an antenna protection hood 1 a according to the invention (transverse to the direction of travel) with the surfaces coated with strip-shaped conductor tracks 12 for the ring line radiator and the terrestrial broadband communication antenna 15. These conductor tracks are in particular angled in a V-shape in the plane transverse to the direction of travel. For high-quality coating of the protective antenna hood 1a from below from the direction of the vertical dashed line, it is advantageous not to fall below the coating angle 19 of a = 5 ° between this line and the surface to be coated at any point.
  2. b) in the representation of a section of the protective antenna hood 1 a according to the invention along the direction of travel, the strip-shaped conductor tracks 12 of the terrestrial receiving antenna 14, which is higher than the broadband communication antenna 15, are shown. In contrast to those of the broadband communication antenna 15, these conductor tracks 12 are angled in a V-shape in the plane along the direction of travel. Both antennas meet in the common terrestrial antenna connection point 13.

List of names:

• Ring line radiator 1
• Antenna protection hood 1a
• Electrically conductive coated circuit board 2
• Ring line 3
• vertical radiators 4, 4a, 4b, 4c, 4d
• Capacitance electrodes 5a, 5b, 5c, 5d
• Antenna connection 5.5e
• conductive base 6
• Ring line coupling points 7,7a, 7b, 7c, 7d
• vertical parts 8
• horizontal parts 9
• Distance of height h 10
• Distance 11
• strip-shaped conductor tracks 12
• terrestrial antenna connection point 13
• terrestrial receiving antenna 14
• broadband terrestrial communication antenna 15
• Reference plane 16
• Processing direction 17
• Coating device 18
• Coating angle 19

Claims (15)

1. A protective antenna cover (1a) composed of dielectric plastic which is formed as a loop radiator for the reception of circularly polarized satellite radio signals and whose opening defines a reference plane (16), said protective antenna cover (1a) comprising a loop (3, 3') and at least one linear radiator (4, 4a - d) connected thereto and extending in the direction of the reference plane (16), wherein the loop (3) and the at least one linear radiator (4, 4a - d) are applied to the inner surface of the protective antenna cover (1a)as a coating and form an electrically conductive and contiguous antenna structure.
2. A protective antenna cover in accordance with claim 1,
   characterized in that
   the contour of the inner surface of the protective antenna cover (1a) is configured by shaping the inner surface of the protective antenna cover (1a) for a design of electrically conductive surfaces in a manner such that the loop (3, 3') is formed on a surface in parallel with the reference plane (16); and/or in that the at least one linear radiator (4, 4a - d) extending toward the reference plane (16) is formed by an electrically conductively coated strip surface.
3. A protective antenna cover in accordance with at least one of the preceding claims,
   characterized in that
   a flat capacitance electrode (5a, 5b, 5c, 5d) is applied in a coated manner as an electrically conductive areal structure on a formation of the inner surface of the protective antenna cover (1a) formed in parallel with and at a spacing (11) from the reference plane (16) and is electrically conductively connected to the lower end of the at least one linear radiator (4, 4a - d).
4. A protective antenna cover in accordance with at least one of the preceding claims,
   characterized in that,
   for the connection of the at least one linear radiator (4, 4a - d) to an electrically conductive base plate (6), a counter-electrode is formed by the electrically conductive base plate (6) at the lower end of said at least one linear radiator (4, 4a - d).
5. A protective antenna cover in accordance with at least one of the preceding claims,
   characterized in that,
   for the capacitive connection of a lower end of the at least one linear radiator (4, 4a - d) to an antenna connector (5) in the plane of an electrically conductive base plate (6), a flat counter-electrode (5e) electrically insulated therefrom is formed which is connected to the antenna connector (5).
6. A protective antenna cover in accordance with at least one of the preceding claims,
   characterized in that,
   at least in the interior, it has the shape of a truncated pyramid or of an internally hollow stepped pyramid whose lower side walls are adjacent to the reference plane (16), with in particular: the stepped pyramid having in parallel with the reference plane (16) two substantially horizontal part surfaces located thereabove in the form of a first peripheral step and a planar top surface disposed thereabove, and with in particular four capacitance electrodes (5a, 5b, 5c, 5d) being located at the lower side of the lower horizontal part surface, in each case in its four corners, and/or with the loop (3) being located at the lower side of the upper top surface.
7. A protective antenna cover in accordance with at least one of the preceding claims,
   characterized in that
   four of the linear radiators (4a, 4b, 4c, 4d) are provided and four capacitance electrodes (5a, 5b, 5c, 5d) are each connected via a respective one of the linear radiators (4a, 4b, 4c, 4d) to a corner of the loop (3, 3') disposed thereabove.
8. A protective antenna cover in accordance with claim 1,
   characterized in that
   the loop (3, 3') is connected at each of its four corners to a respective linear radiator (4a, 4b, 4c, 4d) which leads, respectively starting from the respective corner, along an inner edge between side walls contacting the corner until it ends at a spacing (11) from the reference plane (16).
9. A protective antenna cover in accordance with claim 1,
   characterized in that
   a plurality of the linear radiators (4a, 4b, 4c, 4d) are connected at a spacing (11) from the reference plane (16) to a respective capacitance electrode (5a, 5b, 5c, 5d) which is configured at a respective corner of the protective antenna cover (1a)in the form of a horizontal surface extending at a spacing (11) from and in parallel with the reference plane (16) and being formed by a gradation of the inner side of the side walls.
10. A protective antenna cover in accordance with at least one of the preceding claims,
    characterized in that
    the electrically conductive coating is applied at least partly in the form of an electrically conductive lattice structure whose mesh is in particular substantially smaller than 1/8 of the wavelength.
11. A protective antenna cover in accordance with at least one of the preceding claims,
    characterized in that
    the loop radiator is combined with at least one terrestrial vertical antenna (14, 15) for further radio services having a terrestrial antenna connector point (13) at the center of the loop (3, 3'), with in particular two terrestrial antennas having a common terrestrial antenna connector point (13) at the center of the loop (3, 3') being present in the protective antenna cover, of which the one is provided as a terrestrial broadband communication antenna (15) for LTE communication and the other terrestrial reception antenna (14) is provided for the coverage of frequency bands at a lower frequency such as LTE communication in the low band or AM/FM/DAB radio reception, with in particular both terrestrial antennas being formed from strip-shaped and electrically conductive conductor tracks (12) which converge cluster-like at the antenna connector point (13) and which are formed from surfaces formed in V shape in the interior of the protective antenna cover (1a).
12. A protective antenna cover in accordance with at least one of the preceding claims,
    characterized in that
    the electrically conductive antenna structure is printed onto the inner jacket surface of the protective antenna cover or is applied using a laser.
13. A protective antenna cover in accordance with at least one of the preceding claims,
    characterized in that
    it has a greater extent in a first direction (direction of travel) in the reference plane than in a second direction extending transversely thereto; and in that conductor tracks (12) of a terrestrial broadband communication antenna (15) are angled out of a plane extending in the first direction and conductor tracks (12) of a higher terrestrial reception antenna (14) are angled out of a plane extending in the first direction.
14. A method of manufacturing a protective antenna cover in accordance with at least one of the preceding claims,
    characterized in that
    the production of the antenna structure takes place in the interior of the protective antenna cover (1a) from a direction (17) which extends substantially perpendicular to the reference plane (16).
15. A method in accordance with claim 14,
    characterized in that
    the antenna structure is printed or is generated with the aid of a laser on the inner side of the protective antenna cover (1a), with in particular the direction (17) having an angle (19) of at least 5° with respect to all the surfaces to be provided with the antenna structure.

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