EP1225653B1 - Diversity antenna on a dielectric area of a car body - Google Patents

Description

The invention relates to a multi-antenna diversity antenna system on a conductively framed dielectric surface in a vehicle body in the meter and Dezimeterwellenbereich z. B. for the audio or television broadcast reception. It is based on a multi-antenna system, as it is used for the design of an antenna diversity system. Such multi-antenna systems are z. B. described in EP 0 269 723 . DE 36 18 452 . DE 39 14 424 , Fig. 14, DE 37 19 692 . P 36 19 704 for windscreens or rear windows. If the RF decoupling of the antennas is adequate, interference in the reception, which occurs in connection with temporal level drops due to the multipath propagation of the electromagnetic waves, occurs when the vehicle is positioned differently in the reception field. This effect is exemplified by the Figures 3 and 4 in EP 0 269 723 explained. The mode of operation of an antenna diversity system is to switch to a different antenna when a reception failure occurs in the signal of the switched-on antenna and to make the number of noise levels leading to interference at the receiver input as small as possible in a given reception field. The level drops, plotted over the route and thus over time, do not occur congruently. The probability of finding an undisturbed signal among the available antennas increases with the number of antenna signals and the diversity decoupling between these signals. A diversity decoupling of the antenna signals in the context of the present invention is present when the received signals, in particular with regard to interference, such. B. falls in the RF level, are different. To obtain good diversity performance usually 3 to 4 sufficiently diversified decoupled antenna signals are required in practice, which are designed according to the prior art usually on the rear window pane under design of the heating field of a motor vehicle. For this purpose, a connection network has to be provided for each antenna - and for reasons of good signal / noise ratios - with an antenna amplifier. Such connection networks are very complex in the variety, in particular together with the respectively required high-frequency connection lines to the receiver.

In the future, modern vehicle technology will see more of the use of plastic body parts, e.g. as plastic rear cover or as plastic parts in the otherwise metallic running vehicle body.

The present invention is based on the DE 195 35 250 , There are in the Figures 2 and 4 Antenna structures 5 and 6 shown for different frequency ranges, for example in the plastic tailgate or in the roof opening of a vehicle. In the DE 195 35 250 each separate antennas are specified for different frequency ranges and it is proposed under the objective to achieve the smallest possible couplings by the greatest possible distances among the antennas of the different frequency ranges, a reasonable spatial distribution of these antennas on the limited space available. According to this prior art would additionally z. As for the reception of VHF radio, four connection networks, ie antenna amplifiers are used, the connection with the vehicle mass at the mounting point and their wiring associated with a considerable effort and would be very cumbersome. For the design of Mehrantennendiversitysystemen with eg 4 from each other due to large spatial distances from each other diversity decoupled antennas with antenna amplifiers with ground connection for diversity FM reception and separately run 4 antennas for the diversity reception of terrestrial television signals after in the DE 195 35 250 given teaching is therefore lacking due to the relatively large wavelengths in these frequency ranges of space.

The invention is therefore an object of the invention to make a space-saving diversity antenna for a diversity antenna system in a vehicle according to the preamble of claim 1 with different selectable received signals, the average quality of reception is as good as possible and simultaneously occurring in the different antenna signals while receiving interference as low as possible.

This object is achieved in a diversity antenna for a diversity antenna system according to the preamble of claim 1 by the characterizing features of claim 1.

• Fig. 1: Grundformen einer Antenne nach der Erfindung
  1. a) mit drahtförmigem Antennenleiter 38 der Länge 9b im Abstand 9a parallel zur leitenden Berandung 1 mit daraus resultierend wirksamen Teilkapazitäten 45 als hochfrequente Verbindung zur leitenden Berandung 1, mit zweipoligem elektronisch steuerbarem Impedanznetzwerk 11 in der weiteren Unterbrechungsstelle 15,16 zur Erreichung unterschiedlicher, diversitätsmäßig entkoppelter Antennensignale 44 am Antennenanschlussklemmenpaar 13,14.
  2. b) mit drahtförmigem Antennenleiter 38 mit konzentrierten Impedanzen Z1, Z2 als hochfrequenzmäßig wirksame Verbindungen 42,43 zur leitenden Berandung 1.
  3. c) als Antenne mit Antennenanschlussklemmenpaar 13,14 seriell zur Impedanz Z1 in der hochfrequenzmäßig wirksamen Verbindung 42 des drahtförmigem Antennenleiters 38 zur leitenden Berandung 1.
  4. d) als Antenne mit Antennenanschlussklemmenpaar 13,14 in der niederohmig ausgeführten Verbindung 42, sodass mit der niederohmigen Verbindung 43 eine Schleife 6 mit zweipoligem elektronisch steuerbarem Impedanznetzwerk 11 in der weiteren Unterbrechungsstelle 15,16 gegeben ist.
  5. e) als Antenne wie in Fig. 1c, wobei jedoch anstelle der Verbindung 43 als Impedanz Z2 (im Bild angedeutet) die Impedanz eines weiteren Antennenleiters 38a wirksam ist und in Fortsetzung dieses Prinzips weitere Antennenleiter 38b und 38c mit weiteren Unterbrechungsstellen 15,16 in voneinander hinreichend großem Abstand mit jeweils einem seriell eingebracht elektronisch steuerbaren Impedanznetzwerk 11 vorhanden sind. Bevorzugte Abstände zwischen den elektronisch steuerbaren Impedanznetzwerken 11 sind nicht kleiner als etwa λ/8. Besonders bevorzugte Abstände sind λ/4 und mehr.
  6. f) als Antenne ähnlich wie in Fig. 1e jedoch mit beidseitiger Fortsetzung des drahtförmigen. Antennenleiters 38 durch weitere Antennenleiter 38a, 38b, 38c nach einer Seite und dem weiteren Antennenleiter 38d nach der anderen Seite, wobei die Impedanz dieses Antennenleiters 38d, angedeutet als wirksame Impedanz Z2 anstelle der Verbindung 43, durch Ausformung des Antennenleiters 38d geeignet gestaltet ist.
  7. g) als Antenne ähnlich wie in Fig. 1a mit Antennenanschlussklemmenpaar 13,14 im drahtförmigen Antennenleiter 38 und mit beidseitiger Fortsetzung des drahtförmigen Antennenleiters 38 durch den weiteren Antennenleiter 38a nach einer Seite und dem weiteren Antennenleiter 38b nach der anderen Seite.
  8. h) als Antenne ähnlich wie in Fig. 1g mit Antennenanschlussklemmenpaar 13,14 im drahtförmigen Antennenleiter 38 zum Abgriff der massefreien Antennenssignale 44b und mit Antennenanschlussklemmenpaar 10,14 zum Abgriff der massebezogenen Antennenssignale 44a.
• Fig. 2: Entstehung der diversitätsmäßig unterschiedlichen Antennensignale am Antennenanschlussklemmenpaar 13,14 bei unterschiedlichen Zuständen des elektronisch steuerbaren Impedanznetzwerks 11 durch die sich dabei ergebende unterschiedliche Überlagerung der magnetischen Effekte, bewirkt durch die magnetischen Feldlinien 3, und der elektrischen Effekte, bewirkt durch die elektrischen Feldlinien 2.
• Fig. 3: Realisierung einer Antenne nach Fig. 2. Das Anschlussnetzwerk 25 enthält Anpassnetzwerke und/oder Verstärker 17,18 zur wahlweisen massefreien oder massebezogenen Antennensignalauskopplung mittels eines elektronischen Umschalters 19 über die Netzwerkkomponenten 17,18 z.B. zu getrennten Antennenanschlussleitungen 46,46a.
• Fig. 4: Antenne in einem Kofferraumdeckel. Der Schaltprozessor 31 im Anschlussnetzwerk 25 liefert die Steuersignale 20 an die Steuersignaleingänge 20a und 20b zur Ansteuerung der steuerbaren Impedanznetzwerke11a und 11b über die hochfrequenzmäßig unwirksame Steuerleitung 47 zur Erzeugung der diversitätsmäßig unterschiedlichen Antennensignale am Eingang des Anp. NW und/oder Verstärkers für massebezogene Antennensignale 18.
• Fig. 5: Wie Fig. 4, jedoch mit zwei elektronisch steuerbaren Impedanznetzwerken 11a und 11b in einer Anordnung mit Ringstruktur 5. Der elektronische Umschalter 19 ermöglicht die wechselweise Auswertung massebezogener Antennensignale zwischen dem Antennenanschlussklemmenpaar 10,14 und massefreier Antennensignale zwischen dem Antennenanschlussklemmenpaar 13 und 14 in der Antennenanschlussleitung 46.
• Fig. 6: Ausführungsformen des elektronisch steuerbaren Impedanznetzwerks 11:
  1. a) Grundfunktionsbild eines elektronisch steuerbaren Impedanznetzwerks 11 mit elektronischem Schaltelelment 12, Steuereingang 20a, Steuersignal 20 und geschalteten Klemmen 15 und 16.
  2. b) Elektronisches Schaltelelement 12 als Schalt- oder PIN-Diode 22 mit hochfrequent durchlässigem Impedanznetzwerk 26 für die Antennensignale und Weiterleitung des Gleichstroms, wenn keine gesonderte Steuerleitung 47 vorhanden ist.
  3. c) Elektronisch steuerbares Impedanznetzwerk 11 für Durchlässigkeit im AM-Frequenzbereich und Sperrung in darüber liegenden Frequenzbereichen des Rundfunks durch die Drossel 21. Wahlweise Verbindung weiterführender Teile des Antennenleiters 38 über die hoch- bzw. niederohmig geschaltete Diode 22.
  4. d) Elektronisch steuerbares Impedanznetzwerk 11 mit im VHF/UHF-Frequenzbereich sperrendem, aber AM und FM durchlässigem Impedanznetzwerk 26a und im AM-Frequenzbereich durchlässigem aber im FM sperrendem Impedanznetzwerk 26b.
  5. e) Elektronisch steuerbares Impedanznetzwerk 11 mit zueinander parallel geführten Steuerleitungen 47, 47a für den Hin- und Rückstrom des Steuersignals 20 mit Koppelkapazität 24 zur gemeinsamen Bildung eines drahtförmigen Antennenleiters 38 bzw. 38a bzw. 38b.... Drossel 21 dient zur Sperrung hochfrequenter Signale bei sperrender Diode 22.
  6. f) Elektronisch steuerbares Impedanznetzwerk 11, wie in Fig. 6e, jedoch mit Impedanznetzwerk 26 zur frequenzselektiven Weiterleitung von Antennensignalen
  7. g) Elektronisch steuerbares Impedanznetzwerk 11 mit Logikschaltung 49 zur Adressierung mehrerer durch drahtförmige Antennenleiter 38, 38a, 38b.. miteinander verbundener elektronisch steuerbarer Impedanznetzwerke 11 für mehrere zueinander parallel geführter, drahtförmiger Leiter zur Gestaltung mehrerer Steuerleitungen 47, 47a, 47b, welche durch zusätzliche Koppelkapazitäten 24 miteinander verkoppelt sind und zusammen als drahtförmiger Antennenleiter 38 bzw. 38a bzw. 38b.. wirken.
  8. h) Elektronisch steuerbares Impedanznetzwerk 11, wie in den Figuren 6f und 6g, jedoch für frequenzselektive Adressierung in unterschiedlichen Frequenzbereichen.
• Fig. 7: Antennensystem wie in Fig. 5, jedoch mit zwei Anschlussnetzwerken 25a und 25b in der Nähe der Heckdeckelscharniere zur Auswertung mehrerer unterschiedlicher sowohl massefreier als auch massebezogener Antennensignale mit Hilfe verschiedener Schalterstellungen in den Anschlussnetzwerken 25a und 25b.
• Fig. 8: Antennensystem wie in Fig. 7 mit Empfänger 33, jedoch mit Diversityprozessor 30, Schaltprozessor 31 zur Erzeugung der Steuersignale des Diversityprozessors 27. Schaltadresssignaleinspeisung 34, Frequenzweiche HF/ZF 32, elektronische Umschalter 19, AM-Verstärker 29, Netzwerkkomponenten 17,18 sind ebenfalls in die Anschlussnetzwerke 25a bzw. 25b integriert.
• Fig. 9: Antennensystem wie in Fig. 8, erweitert um 4 TV-Antennen mit TV-Verstärkern 36a, 36b, 36c, 36d und den TV-Antennenanschlusskabel 37a, 37b, 37c, 37d.
• Fig. 10: Antennensystem wie in Fig. 9, wobei beispielhaft die in den elektronisch steuerbaren Impedanznetzwerken 11a,b,c geschlossenen HF-Verbindungen für 4 unterschiedliche FM-Empfangssignale FM1-FM4, für 4 unterschiedliche TV- Empfangssignale TV1-TV4 und ein AM-Empfangssignal angegeben sind.
• Fig. 11: Mögliche Anordnung der Elemente des Antennensystems nach Fig. 10 im aufgeklappten Heckdeckel.
• Fig. 12: Anordnung eines Antennensystems nach der Erfindung in einem Dachausschnitt eines Fahrzeugs.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below. In detail show:

• Fig. 1 : Basic forms of an antenna according to the invention
  1. a) with wire-shaped antenna conductor 38 of length 9b at a distance 9a parallel to the conductive boundary 1 with resulting effective partial capacities 45 as a high-frequency connection to the conductive boundary 1, with bipolar electronically controllable impedance network 11 in the other point of interruption 15,16 to achieve different, diversity decoupled Antenna signals 44 at Antennenanschlussklemmenpaar 13,14.
  2. b) with a wire-shaped antenna conductor 38 with concentrated impedances Z1, Z2 as high-frequency-effective connections 42, 43 to the conductive boundary 1.
  3. c) as an antenna with Antennenanschlussklemmenpaar 13,14 serially to the impedance Z1 in the high-frequency effective connection 42 of the wire-shaped antenna conductor 38 to the conductive boundary. 1
  4. d) as an antenna with Antennenanschlussklemmenpaar 13,14 in the low impedance connection 42, so that the low-resistance connection 43 is a loop 6 with bipolar electronically controllable impedance network 11 in the other point of interruption 15,16 is given.
  5. e) as an antenna as in Fig. 1c However, instead of the connection 43 as impedance Z2 (indicated in the picture), the impedance of another antenna conductor 38a is effective and in continuation of this principle, further antenna conductors 38b and 38c with further interruption points 15,16 in mutually sufficiently large distance each with a serially introduced electronically controllable impedance network 11 are present. Preferred distances between the electronically controllable impedance networks 11 are not less than about λ / 8. Particularly preferred distances are λ / 4 and more.
  6. f) as an antenna similar to in Fig. 1e but with bilateral continuation of the wire-shaped. Antenna conductor 38 by further antenna conductors 38a, 38b, 38c to one side and the other antenna conductor 38d to the other side, wherein the impedance of this antenna conductor 38d, indicated as effective impedance Z2 instead of the connection 43, designed by shaping the antenna conductor 38d suitable.
  7. g) as an antenna similar to in Fig. 1a with Antennenanschlussklemmenpaar 13,14 in the wire-shaped antenna conductor 38 and with two-sided continuation of the wire-shaped antenna conductor 38 through the further antenna conductor 38a to one side and the other antenna conductor 38b to the other side.
  8. h) as an antenna similar to in Fig. 1g with antenna connection terminal pair 13, 14 in the wire-shaped antenna conductor 38 for tapping off the ground-free antenna signals 44b and with antenna connection terminal pair 10, 14 for tapping off the ground-related antenna signals 44a.
• Fig. 2 : Generation of diversity-different antenna signals at Antennenanschlussklemmenpaar 13,14 at different states of the electronically controllable impedance network 11 by the resulting different superposition of the magnetic effects caused by the magnetic field lines 3, and the electrical effects caused by the electric field lines. 2
• Fig. 3 : Realization of an antenna after Fig. 2 , The connection network 25 contains matching networks and / or amplifiers 17, 18 for selectively ground-free or ground-related antenna signal extraction by means of an electronic changeover switch 19 via the network components 17, 18, for example to separate antenna connection lines 46, 46a.
• Fig. 4 : Antenna in a trunk lid. The switching processor 31 in the connection network 25 supplies the control signals 20 to the control signal inputs 20a and 20b for driving the controllable impedance networks 11a and 11b via the high-frequency ineffective control line 47 for generating the diversely different antenna signals at the input of the Anp. NW and / or amplifier for ground related antenna signals 18.
• Fig. 5 : As Fig. 4 However, with two electronically controllable impedance networks 11a and 11b in a ring structure 5. The electronic switch 19 allows the mutual evaluation of ground-related antenna signals between the antenna terminal pair 10,14 and groundless antenna signals between the antenna terminal pair 13 and 14 in the antenna connection line 46th
• Fig. 6 Embodiments of the Electronically Controllable Impedance Network 11:
  1. a) Basic function image of an electronically controllable impedance network 11 with electronic Schaltelelment 12, control input 20a, control signal 20 and switched terminals 15 and 16.
  2. b) Electronic Schaltelelement 12 as a switching or PIN diode 22 with high-frequency permeable impedance network 26 for the antenna signals and forwarding of the DC current, if no separate control line 47 is present.
  3. c) Electronically controllable impedance network 11 for transmission in the AM frequency range and blocking in overlying frequency ranges of broadcasting through the choke 21. Optionally, connection of further parts of the antenna conductor 38 via the high or low impedance connected diode 22nd
  4. d) Electronically controllable impedance network 11 with blocking in the VHF / UHF frequency range, but permeable AM and FM impedance network 26a and in the AM frequency range permeable but in the FM blocking impedance network 26b.
  5. e) Electronically controllable impedance network 11 with mutually parallel control lines 47, 47a for the outward and return current of the control signal 20 with coupling capacity 24 for the common formation of a wire-shaped antenna conductor 38 or 38a and 38b .... Throttle 21 is used to block high-frequency signals with blocking diode 22.
  6. f) electronically controllable impedance network 11, as in Fig. 6e but with impedance network 26 for the frequency-selective transmission of antenna signals
  7. g) Electronically controllable impedance network 11 with logic circuit 49 for addressing a plurality of wire-shaped antenna conductors 38, 38a, 38b .. interconnected electronically controllable impedance networks 11 for a plurality of mutually parallel guided, wire-shaped conductor for designing a plurality of control lines 47, 47a, 47b, which by additional coupling capacitances 24 are coupled together and act together as a wire-shaped antenna conductor 38 and 38 a and 38 b .. ..
  8. h) electronically controllable impedance network 11, as in the Figures 6f and 6g , but for frequency-selective addressing in different frequency ranges.
• Fig. 7 : Antenna system as in Fig. 5 but with two connection networks 25a and 25b in the vicinity of the trunk lid hinges for evaluating a plurality of different ground-free as well as ground-related antenna signals by means of various switch positions in the connection networks 25a and 25b.
• Fig. 8 : Antenna system as in Fig. 7 with receiver 33, but with diversity processor 30, switching processor 31 for generating the control signals of the diversity processor 27. Switch address signal feed 34, crossover HF / ZF 32, electronic switches 19, AM amplifiers 29, network components 17,18 are also integrated into the access networks 25a and 25b.
• Fig. 9 : Antenna system as in Fig. 8 , expanded by 4 TV antennas with TV amplifiers 36a, 36b, 36c, 36d and the TV antenna connection cable 37a, 37b, 37c, 37d.
• Fig. 10 : Antenna system as in Fig. 9 , wherein by way of example the RF connections closed in the electronically controllable impedance networks 11a, b, c are indicated for 4 different FM reception signals FM1-FM4, for 4 different TV reception signals TV1-TV4 and one AM reception signal.
• Fig. 11 : Possible arrangement of the elements of the antenna system after Fig. 10 in the unfolded boot lid.
• Fig. 12 : Arrangement of an antenna system according to the invention in a roof opening of a vehicle.

With the invention, the advantageous possibility associated with only one conductor structure, which is laid in a space-saving manner in the edge region of the dielectric surface 7, and with only one connection network 25 to produce a plurality of diversity-different antenna signals. The electronically controllable impedance networks 11, for which no connection to the vehicle mass is necessary, can be designed and housed in a simple manner to save space. It is also advantageous that the mobility of the boot lid is not limited by the freedom of mass of the electronically controllable impedance networks 11.

The operation of the invention will be described with reference to the in Fig. 1 described basic forms of antennas described. In Fig. 1a On a dielectric surface 7, a wire-shaped antenna conductor 38 of length 9b is mounted at a distance 9a parallel to the conductive boundary 1. Due to the concentration of the electric field lines 2 and the magnetic field lines 3, which cause the received electromagnetic waves in the immediate vicinity of the conductive boundary 1, the coupling of both the electrically and the magnetically coupled components of the received signal in the wire-shaped antenna conductor 38 is at very much small distance 9a relatively large. In this case, the edge effect at the conductive boundary 1 causes the concentration of the electric field lines 2 and the edge flux 4 occurring at the edge the concentration of the magnetic field lines 3 in the immediate vicinity of the edge of the conductive boundary 1. Due to the substantially static distributions of both the electric field lines 2 as well as the magnetic field lines 3 near the edge, the minimum necessary distance 9a is not measured at the wavelength of the received waves. Rather, it is already possible, for example at λ = 3m wavelength with a distance 9a of λ / 50, to achieve sufficient antenna properties. In order to generate diversity-different antenna signals at a suitable point of interruption at Antennenanschlussklemmenpaar 13,14 with the antenna voltage 44 thereon according to the invention an electronically controllable impedance network 11 is inserted into the wire-shaped antenna conductor 38 serially, which is shown as a switch. If neither the antenna connection terminal pair 13, 14 nor the electronically controllable impedance network 11 is located at one end of the wire-shaped antenna conductor 38 and, furthermore, is the distance between the antenna connection terminal pair 13, 14 and the electronically controllable impedance network 11 sufficiently large, then different impedances result in the other Interruption point 15,16 different antenna signals 44. This is explained by the effect of effective between the wire-shaped antenna conductor 38 and the conductive boundary 1, running capacity, which is indicated as 45. Thus, different impedances result in different superpositions of the magnetic effects due to the loop voltage generated by the magnetic field lines 3 and the electrical effects generated by the electric field lines 2. As a result of the complexity of the influence of the vehicle compared to the wavelength on the current distribution on the body and thus also on the edge current 4 and with this accompanying magnetic field lines 3 and as a result of largely decorrelated forming electric field lines 2 and the different antenna signals 44 are diversity differently.

In Fig. 1b The effective at the antenna conductor 38 spare capacitances 45 are supported by high-frequency effective connections 42 and 43 in the form of the impedances Z1 and Z2 connected to the conductive boundary 1. If the high-frequency effective connections 42 and 43 carried by the impedances Z1 and Z2 low impedance, so form the conductive boundary 1, the high frequency moderate low-impedance connections 42 and 43 and the antenna conductor 38 a loop 6, if in addition the electronic switching element 12th low impedance, the further interruption point 15,16 bridges with a corresponding antenna voltage 44. At high impedance switched electronically controllable impedance network 11, the antenna voltage 44 is different in diversity.

In a further basic form of the invention is in Fig. 1c the antenna terminal pair 13,14 in one of the high frequency effective connections 42 or 43 of the wire-shaped antenna conductor 38 inserted serially.

In a further embodiment of an antenna according to the invention is in Fig. 1d the wire-shaped antenna conductor 38 is formed at its ends as connections 42 and 43 to the conductive boundary 1, so that with the help of different impedances of the electronically controllable impedance network 11 between a magnetically receiving antenna effect at low impedance and one of them decorrelated electrically receiving antenna can be switched at high impedance.

In an advantageous embodiment of the invention is in Fig. 1e a first further antenna conductor 38a is connected to one of the two ends of the antenna conductor 38 and the first further antenna conductor 38a is designed such that the high-frequency load associated with the connection corresponds to the suitably set impedance Z2 and forms the high-frequency effective connection 43. If a second further antenna conductor 38b is connected to the other end of the first further antenna conductor 38a, this second further antenna conductor 38b is designed in continuation of this principle so that the high-frequency load accompanying the connection corresponds to the suitably set impedance and the high-frequency-effective connection 43 or 42 forms. In this case, the second further antenna conductor 38b is led parallel to a further section of the boundary 1. In the example shown, the antenna voltage 44 is tapped at the antenna terminal pair 13, 14 on a ground-related basis. If each of the further antenna conductors contains an electronically controllable impedance network 11 at a suitable distance from each other, then the in Fig. 1e illustrated structure, with which a variety of diversely different antenna voltages 44 can be achieved with different settings of the electronically controllable impedance networks 11. The advantage of this arrangement according to the invention is that the different antenna signals are set at a single antenna connection point on the antenna connection terminal pair 13, 14 and these signals are combined in a single antenna connection Connection network 25 can be tapped. Thus eliminates the case of remote from each other antennas, the plurality of such connection networks 25 and their connection to another common connection network 25 for further processing of the signals in the diversity system.

To expand the variety of available antenna voltages 44 is discussed in Fig. 1f in an analogous continuation of the inventive concept with ground-related tapping of the antenna voltage 44, the effective impedance Z 2 instead of the connection 43 realized by suitably shaped shaping of the antenna conductor 38 d. At its other end, the wire-shaped antenna conductor 38 is analogous to Fig. 1e with the other antenna conductors 38a, b, c .. configured.

In a further advantageous embodiment of the invention, the antenna voltage 44 when placing the Antennenanschlussklemmenpaar 13,14 as an interruption point in parallel to the conductive boundary led part 1 of the wire-shaped antenna conductor 38 can be tapped off mass. As in Fig. 1g shown, the wire-shaped antenna conductor 38 is continued on both sides with further antenna conductors 38a and 38b.

In a particularly advantageous embodiment of the invention is in Fig. 1h a first point of interruption for an antenna terminal pair 13, 14 for ground-free tapping of the antenna voltage 44b and another antenna terminal pair 14, 10 for tapping the diversity-different receiving voltage 44a. The tap of the ground-related antenna voltage 44a takes place between the interruption point 14 of the antenna conductor 38 and the conductive boundary 1, which is described by the ground point 10. By tapping off both antenna voltages 44 at a common location, both signals can also be further processed in a single connection network 25.

Based on Fig. 2 the operation of an advantageous basic form of an antenna according to the invention in a plastic trunk lid, which represents the dielectric surface 7, explained. Here, the antenna conductor 38 is guided as a ring structure 5 with the width 9f and the length 9e substantially parallel to three sections of the conductive boundary 1. The diversity of different antenna signals at Antennenanschlussklemmenpaar 13,14 caused by the different settings of the electronically controllable impedance network 11. The antenna signals can both ground on the terminal pair 13, 14th or ground-based on terminal pair 13,10 or 14, 10 are tapped. The different excitation of the ring structure with its further point of interruption 15,16 is based on the effect of the electrical and magnetic excitation differ in the different settings of the electronically controllable impedance network 11 with open-ended and closed ring structure with earth-related tap of the antenna signal and ground-free tap of the antenna signal so that the desired diversity of the diversity of different antenna signals is given. This is illustrated by the equivalent circuit diagram with the equivalent elements of the equivalent inductances 50 and the equivalent capacitances 45 in connection with the electric field lines 2 and magnetic field lines 3.

Fig. 3 shows the realization of an antenna Fig. 2 , In this case, the antenna signals are fed to a connection network 25. The access network 25 includes a matching network and / or an amplifier 17 for groundless Antennensignalauskopplung at the terminals 13,14 and a matching network and / or amplifier 18 ground related Antennensignalauskopplung between the terminals 14 and 10. By means of an electronic switch 19 can either one of the two antenna signals via the network components 17,18 example, separate antenna connection lines 46,46a are supplied. Particularly advantageously, the control signal 20 for controlling the changeover switch 19 is also used to control the electronically controllable impedance network 11 in the form of an electronic switching element 12, in order to effect a HF-moderate separation of the ring structure. This control signal 20 may be derived, for example, from a diversity processor.

In Fig. 4 is the advantageous embodiment of the antenna conductor 38 accordingly Fig. 1e shown in a trunk lid. The antenna conductor 38 is extended by a first further antenna conductor 38a and a further first further antenna conductor 38b, which are connected by the further interruption points 15a, 16a and 15b, 16b via the electronically controllable impedance networks 11a and 11b. The switch processor 31 implemented in the connection network 25 controls the electronically controllable impedance networks 11a and 11b which supply the control signals 20 for the control signal inputs 20a and 20b which are supplied thereto via a high-frequency ineffective control line 47 for generating the diversity-different antenna signals at the input of the matching network and / or amplifier 18 for ground related antenna signals.

In an advantageous development of the invention are in Fig. 5 , starting from the Fig. 3 and 4 , two electronically controllable impedance networks 11a and 11b introduced into the ring structure 5. If the controllable electronic impedance networks 11a and 11b realized as electronic switching elements 12 in the form of PIN diodes, the antenna conductor 38 can take over the function of the control line 47 in addition, if the following antenna signals are to be tapped: If the electronic switching elements 12 are open, so For example, 3 different antenna signals can be tapped: a) ground-based tap on the terminal pair 14, 10, b) ground-related tap on the pair of terminals 13, 10, c) ground-free tap on the pair of terminals 13, 14. If the electronic switching elements 12 are turned on, a different antenna signal can be tapped off at terminal pair 13, 14. Thus, to obtain 4 different antenna signals, the switching processor 31 must be activated only once via the control signals 20. The electronic switch 19, driven by the control signals 20, lead the antenna signals to the matching network and / or amplifier 17 for ground-free tapped antenna signals or 18 for earth-related tapped antenna signals. On the output side, the amplified or adapted antenna signals corresponding to the control signals 20 are fed via an electronic switch 19 to an antenna connection line 46 in the connection network 25.

In Fig. 6 Some examples of advantageous embodiments of the electronically controllable impedance network 11 are shown. These networks do not require connections to the vehicle ground at their mounting point when the control signals 20 for controlling the impedances of the electronically controllable impedance networks 11 either, if possible, via the wire-shaped antenna conductor 38 directly or according to the invention via control lines 47, 47a, 47b, which directly high-frequency ineffective immediately are guided parallel to the wire-shaped antenna conductor 38, so that the strand thus formed electrically acts as a wire-shaped antenna conductor 38. The electronically controllable impedance networks 11 are preferably designed as electronic switches 12, switching or PIN diodes 22 preferably being used as switching elements. If control signals 20 are to be supplied via an electronically controllable impedance network 11 to a further wire-shaped antenna conductor 38 with control line 47, 47a, 47b, this is done according to the invention via a choke 21 so as not to impair the longitudinal impedance of the electronically controllable impedance network 11 in the case of a high-resistance switching diode 22 , Advantageous embodiments for different applications are in the Figures 6a to 6h shown.

Herein shows Fig. 6a the block diagram of an electronically controllable impedance network 11 in its simplest embodiment, only consisting of an electronic switching element 12, which is connected via the control signal 20 at its control input 20a. Thus, this electronic switching element has the function of a switch with the terminals 15 and 16.

In Fig. 6b the electronic switch 12 is designed as a switching or PIN diode 22. The antenna conductor 38 simultaneously assumes the function of the control line 47. The impedance network 26 is designed such that z. B. the FM frequency range is permeable to the series resonant circuit and is impermeable to all other radio frequencies. The parallel-connected inductance serves on the one hand to forward the direct current and on the other hand, for example, a parallel resonance can be generated in the TV band 1, so that the blocking effect of the impedance network 26 is increased in this frequency range.

In Fig. 6c is the electronically controllable impedance network 11 designed to be permeable to the AM frequency range and locked for the overlying frequency ranges of the radio through the throttle 21. The capacitor 23 is used for DC separation. About the low-impedance diode 22 z. B. further parts of the antenna conductor 38 a are connected to the antenna conductor 38.

In Fig. 6d For example, the electronically controllable impedance network 11 is configured such that the impedance network 26a blocks the VHF / UHF frequency ranges, but passes AM and FM signals, while the impedance network 26b passes the AM frequency range and blocks the FM frequency range.

In Fig. 6g is the block diagram of an electronically controllable impedance network 11 indicated, which allows an addressable switching function, for example via a stepped DC voltage as a control signal 20. If, for example, a plurality of electronically controllable impedance networks 11 in a ring structure 5 can be addressed at different times and for different frequency ranges at different positions in the ring structure 5, at least 2 conductors are required for driving. It is useful to use three ladders. A conductor is formed by the antenna conductor 38 itself, forming two further conductors 47a and 47b the control lines. All 3 conductors are high-frequency connected in parallel via coupling capacitors 34 and act in close spatial proximity as an antenna conductor 38. The control line 47a supplies, for example, the switching address signal in the form of a stepped DC voltage in the simplest case. The antenna conductor 38 can additionally supply a DC supply voltage for the switching signal address evaluation in the logic circuit 49 and the control line 47b serves as a return conductor. The coupling of these lines at the input and output of the electronically controllable impedance network 11 to the logic circuit 49 via chokes 21, which are sufficiently high impedance in the considered frequency range. The Schaltadresssignalauswertung in the logic circuit 49 is here most easily realized by window discriminators.

In the Fig. 6e and 6f simple switching examples are shown, wherein the control of the electronic Schaltelelementes 12 takes the form of a diode 22 via a forward and return conductors.

Fig. 6h shows the electronically controllable impedance network 11 configured addressable switchable for different frequency ranges.

In Fig. 7 is for that in Fig. 5 illustrated example of an antenna in the trunk lid to further increase the diversity of the diversity of different antenna signals in a manner advantageous to a connection network 25 extended. The problem-free attachment of two terminal units 25a and 25b in the vicinity of the Heckdeckelschamiere with the available there the possibility of connection to the vehicle mass allows the evaluation of several different both groundless and ground related antenna signals using various switch positions in the connection networks 25a and 25b. The selected antenna voltages 44 are available separately at the antenna connection lines 46, 46a. These signals can be advantageously supplied to an antenna diversity receiver with two signal inputs for in-phase superimposition of the received signals. Such receivers are preferably used for FM radio reception and are for example from the US 4079318 as well as from the U.S. Patent 5,517,696 known. These diversity receivers aim to achieve a larger useful signal by in-phase superposition of two or even more antenna signals in the sum branch than with a single antenna. By supplementing such a diversity system according to the invention with a scanning diversity system with a detector for displaying interference in the sum branch and a diversity processor In order to generate control signals 20 for selecting two undisturbed signals in the antenna connection lines 46, 46a, an antenna according to the present invention can further reduce the frequency of interference in the area with multipath propagation and level dips by a multiple.

For a pure scanning diversity system with only one selected at any time and the antenna connection line 46 the receiver 33 fed antenna signal 44 is in Fig. 8 an advantageous development of the antenna system according to Fig. 7 shown. In this case, the antenna voltage 44 selected in the connection network 25b with the aid of the electronic changeover switch 19 is fed via the antenna connection line 46a to the connection network 25a in order optionally to be available there for forwarding to the antenna connection line 46. With the aid of the HF / IF crossover 32, the IF signals coming from the receiver 33 are supplied to the diversity processor 30 with switching processor 31. The latter controls both the electronic switch 19 and the Schaltadresssignaleinspeisung 34. The switching signals conducted via the antenna connection line 46a control the electronic changeover switches 19b via the switching address signal evaluation 35 and initiate control signals 20 for controlling the electronically controllable impedance networks 11. In addition, an AM amplifier 29 can be accommodated in the connection network 25a.

In a very advantageous manner, according to another embodiment of the invention. Fig. 9 the antenna system as in Fig. 8 4 TV antennas with TV amplifiers 36a, 36b, 36c, 36d for terrestrial television (Bd1, VHF, UHF) are extended. Modern TV diversity systems often require 4 separate antenna signals, which should be available simultaneously. These signals are in Fig. 9 fed via the TV antenna cable 37a, 37b, 37c, 37d the TV diversity system.

In Fig. 10 are for an antenna system like in Fig. 9 by way of example the RF connections closed in the electronically controllable impedance networks 11a, b, c for 4 different FM reception signals FM1 to FM4, for 4 different TV reception signals TV1 to TV4 and an AM reception signal. With this arrangement as a ring structure with three electronically controllable impedance networks 11 and only two connection networks 25 antenna signals are achieved with very high diversity efficiency. This is done by choosing an advantageous distance between the electronically controllable impedance networks 11 with each other and between the access networks 25 and the electronically controllable impedance networks 11. For the given ring structure, distances 9d (see eg Fig. 5 ), which are not smaller than about λ / 8, as very advantageous. A safe diversification of the antenna signals is achieved with distances of λ / 4 and more. These distances may be maintained at VHF and frequency higher VHF / UHF frequencies in passenger cars. Due to the possible proximity of the wire-shaped antenna conductor 38 to the edge of the boot lid and the small design size of the electronically controllable impedance networks 11 remains in the middle of the horizontal area much space for the accommodation of telephone and satellite antennas or other antenna structures for additional services, eg telecontrol functions. However, care must be taken here that the function of the diversity antenna according to the invention is not impaired, in particular, by the connecting cable thereof. This can happen, on the one hand, that sheath currents, for example on the telephone supply cables, are prevented by suitable measures in the useful frequency range of the diversity antenna, or sufficient decoupling to the diversity antenna is brought about by suitable cable routing. Due to the strong electromagnetic coupling of the wire-shaped antenna conductor 38 with the conductive boundary 1 of the dielectrically designed trunk lid in the closed state, the coupling with the other antennas can often be advantageously made small.

Fig. 11 shows for an antenna system according to the FIGS. 7 . 8th . 9 and 10 an advantageous arrangement of the elements of the antenna system in the unfolded boot lid. The ground reference for the connection networks 25 can be done via the always metallic running trunk lid attachment 39.

In modern vehicle construction plastic surfaces are also used in cutouts of the metallic vehicle roof 41. Fig. 12 shows an embodiment of the antenna arrangement according to the invention, as in one of Fig. 7 . 8th . 9 analogous manner can be used in a roof opening.

LIST OF REFERENCE NUMBERS Diversity antenna on a dielectric surface in a vehicle body

• leading edge 1
• electric field lines 2
• magnetic field lines 3
• Edge current 4
• Ring structure 5
• Loop 6
• dielectric surface 7
• Taillights 8
• Length of the antenna conductor 38: 9b
• Distance of the antenna conductor from the conductive boundary 9a
• Distance of anti-terminal pair to 11: 9c, 9c '
• Distance between electronically controlled impedance networks 11: 9d
• Earth point 10
• electronically controllable impedance network 11
• electronic switching element or electronic switch 12
• Antenna terminal pair 13,14
• further point of interruption 15,16
• Impedances Z1, Z2
• Wire-shaped antenna conductor 38
• first further antenna conductor 38a
• second further antenna conductor 38b
• high frequency compounds 42,43
• Antenna signal or antenna voltage 44
• Adj. NW and / or Verst. for groundless antenna signals 17
• Adj. NW and / or Verst. for ground-related antenna signals 18.
• Antenna connection line 46
• Network components 17,18
• Electronic changeover switch 19
• Control signal 20
• Control signal input 20a, 20b ....
• Throttle 21
• Switching diode 22
• Capacitor 23
• Coupling capacity 24
• Connection network 25
• first connection network 25a
• second connection network 25b
• Impedance network 26
• Control signals of the switching processor 27
• AM amplifier 29
• Diversity processor 30
• Switching processor 31
• Crossover HF / ZF 32
• Receiver 33
• Switch address signal feed 34
• Switch address signal evaluation 35
• TV amplifier 36
• TV antenna connection cable 37
• Boot lid attachment 39
• Vehicle mass 40
• Vehicle roof 41
• Replacement capacity 45
• Control line 47, 47a, 47b
• Logic circuit 49
• Spare inductance 50

Claims (26)

1. Antenna for use in diversity reception in the range of meter waves and decimeter waves, comprising:

   a dielectric surface (7) for a motor vehicle body, e.g. for a roof section or a trunk with dielectric trunk lid, which is conductively framed and composed of rectangular-shaped partial areas;

   a wire-shaped antenna conductor (38);

   a connecting terminal pair (13, 14);

   at least one two-pole electronically controllable impedance network (11);

   characterized in that

   the wire-shaped antenna conductor (38) is guided on the dielectric surface (7) and parallel to at least a portion of the conductive frame (1) of the dielectric surface (7) at a distance (9a) of less than a quarter of the existing width of the dielectric surface (7) and the wire-shaped antenna conductor (38) comprises a break point (15, 16) with the antenna connecting terminal pair (13, 14) and wherein a two-pole electronically controllable impedance network is serially inserted at at least a further break point and the distance between the antenna connection terminal pair and the at least one electronically controllable impedance network (11) and possibly the distance amongst electronically controllable impedance networks themselves is greater than one eighth of the wavelength used for communications and various antenna signals (44) are achievable at the antenna connecting terminal pair (13, 14) by various settings of the at least one controllable impedance network (11) for use in diversity reception.
2. Antenna according to claim 1,
   characterized in that
   the wire-shaped antenna conductor (38) is guided in parallel to at least one part of the conductive frame (1) of the dielectric surface (7) in a small distance (9a) to the conductive frame (1) in comparison to the length (9b) of the wire-shaped antenna conductor (38) and in comparison to the wavelength λ, but of at least λ/50, and the wire-shaped antenna conductor (38) at both ends is guided to the conductive frame (1) and is connected with the conductive frame (1) via connections (42, 43) effective for high frequency with low impedance such, that a high-frequency loop (6) is formed by the wire-shaped antenna conductor (38) together with the conductive frame (1) (Fig. 1b, c, d).
3. Antenna according to claim 2,
   characterized in that
   the two-pole electronically controllable impedance network (11) is implemented as electronic switch (12) and the high frequency effective connections (42, 43) are provided as impedances Z1 and Z2, whose impedance values are fixed (Fig. 1b, c).
4. Antenna according to one of the claims 1, 3
   characterized in that
   the antenna connecting terminal pair (13, 14) is serially inserted into the longitudinal portion, i.e. into the part of the wire-shaped antenna conductor (38) guided in parallel to the conductive frame (1), at a break point of the wire-shaped antenna conductors (38, 38a, 38b,...) such that the antenna signals (44) can be tapped without ground connection, i.e. without high frequency conductive connection to the conductive frame (1) (Fig. 1 g).
5. Antenna according to one of the claims 2, 3
   characterized in that
   the antenna connecting terminal pair (13, 14) is serially inserted into the high frequency effective connection (42, 43) of one of the two ends of the wire-shaped antenna conductor (38) with the conductive frame (1) (Fig. 1c, d, e, f).
6. Antenna according to claim 3
   characterized in that
   a first additional antenna conductor (38d) is present and connected to one of the two ends of the wire-shaped antenna conductor (38) and the effective impedance Z2 is formed by the high frequency load associated with the connection of the first additional antenna conductor (38d) (Fig. 1f).
7. Antenna according to claim 6
   characterized in that
   in addition to a first additional antenna conductor (38a), a second additional antenna conductor (38b) is connected to the other of the two ends of the wire-shaped antenna conductor (38) and also the effective impedance Z1 is formed by the high frequency load associated with the connection of the second additional antenna conductor (38b) such that the high frequency load associated therewith on both ends of the antenna conductor (38) corresponds to the effective impedance Z1 and Z2, respectively (Fig. 1g).
8. Antenna according to claim 7
   characterized in that
   the additional antenna conductor or the additional antenna conductors (38a and 38b) is/are also wire-shaped and is/are guided in continuation of the wire-shaped antenna conductor (38) at least partially in an electrically small distance (9a) of the conductive frame (1) (Fig. 1g).
9. Antenna according to claim 8
   characterized in that
   in the additional wire-shaped antenna conductors (38a, 38b) a plurality of additional break points (15, 16) are formed, whose distances from each other are greater than λ/8 and preferably greater than λ/4 and into each of which an electronically controllable impedance network (11) or formed as electronic switch (12) is serially inserted, respectively (Fig. 1f, 4).
10. Antenna according to claim 4 in connection with claim 5 and according to claim 9
    characterized in that
    a first antenna connecting terminal pair (13,14) is inserted into a break point of the wire-shaped antenna conductor (38) for tapping the floating ground antenna signals (44b), and at the same location a further antenna connecting terminal pair (10,14) is present in the electrically short high frequency effective connection (42) between the break point (14) of the wire-shaped antenna conductor (38) and the conductive frame (1), so that in one location both the ground-based antenna signals 44a, present between the antenna conductor (38) and the conductive frame (1), and the floating ground antenna signals 44b of the wire-shaped antenna conductor (38), present at the further antenna connecting terminal pair (13,14), are available (Fig. 1h).
11. Antenna according to claim 10
    characterized in that
    an electronic switch (19) is provided, wherein a network component (17) of an antenna diversity system is connected to one output thereof for tapping the floating ground antenna signals 44b and a network component (18) of said antenna diversity system is connected to the other output thereof for tapping the ground-related antenna signals (44a) (Fig. 3).
12. Antenna according to claim 11
    characterized in that
    the wire-shaped antenna conductor (38) is guided as ring structure (5) in a distance of at least λ/50 of the conductive frame (1) with at least one two-pole electronically controllable impedance network (11) within the dielectric surface (7), thus both the ground-related antenna signal between the ring structure (5) and the conductive frame (1) and the floating ground antenna signal in the longitudinal portion of the wire-shaped antenna conductor (38) are available for further processing in the network components (17, 18) of an antenna diversity system (Fig. 2, 3, 5).
13. Antenna according to one of the claims 1 to 12
    characterized in that
    at least one control signal input (20a) is provided at the electronically controllable impedance network (11) for adjusting the effective impedance value between the first HF terminal (15) and the second HF terminal (16).
14. Antenna according to one of the claims 1 to 13
    characterized in that
    at least one digitally adjustable electronic switching element (12) with discrete switching states in conjunction with reactances, where applicable, is provided in the electronically controllable impedance network (11) for setting discrete impedance values, and the setting of the discrete impedance values is achievable by applying one or optionally more digital control signals (20).
15. Antenna according to claim 14
    characterized in that
    the electronic switching element (12) controllable in its high frequency effective permeability by control signals (20) is provided in the electronically controllable impedance network (11) between the connecting terminal pair of the at least one additional break point (15, 16), preferably configured as switching diode (22) controllable between a high frequency closed state and a high frequency open state, and a control signal input (20a) is provided at the impedance network (11) where the control signals (20) for controlling the high frequency effective permeability of the controllable electronic switching element (12) are supplied (Fig. 6a).
16. Antenna according to claim 15
    characterized in that
    the electronically controllable impedance network (11) includes a switching diode (22) controllable between a high frequency closed state and a high frequency open state and, for supplying the control signal (20) in form of the on-state current of the diode and its block voltage, a two-wire line (47, 47a) is formed as a control line such that the two-wire line is formed in high frequency terms as a single wire-shaped antenna conductor (38) by capacitive and inductive coupling of the conductors of the two-wire line and the control signal (20) is passed between the two conductors of the two-wire line (Fig. 6e, f, g, h).
17. Antenna according to claim 16
    characterized in that
    for separation of high-frequency antenna signals and control signals (20) a coupling capacitance (24) that has a low impedance only for high frequencies and an inductor (21) that has high impedance only for high frequencies are provided in the electronically controllable impedance network (11) (Fig. 6e, f, g, h).
18. Antenna according to one of the claims 16, 17
    characterized in that
    for relaying control signals (20) via a first electronically controllable impedance network (11a) to another electronically controllable impedance network (11b) using another wire-shaped antenna conductor (38) configured as two-wire line or as multi-wire line in the first controllable impedance network (11a) switching elements blocking the high-frequency signals, as e.g. inductors (21), are provided for bridging the electronic switching element (12) (Fig. 6g, h).
19. Antenna according to one of the claims 16 to 18
    characterized in that
    a logic circuit (49) is provided in the electronically controllable impedance network (11) for addressable control of the electronic switching element (12) using encoded control signals (20), possibly providing correspondingly encoded signals to a further controllable impedance network (11) via a further wire-shaped antenna conductor (38) configured as two-wire or as multi-wire line (Fig. 6g).
20. Antenna according to one of the claims 16 to 19
    characterized in that
    one or more impedance networks (26) is/are provided for frequency-selective forwarding or blocking of high frequency signals of different broadcasting ranges between the connecting terminals of the other break point (15, 16) of the wire-shaped antenna conductor (38) in the electronically controllable impedance network (11) (Fig. 6b, c, d, f, h).
21. Antenna according to one of the claims 10 to 20
    characterized in that
    a connection network (25) is connected to the antenna connecting terminal pair (13,14), wherein the floating ground and/or the ground-related antenna signal (44) is adapted respectively via network components (17, 18) to a receiver (33), and a switching processor (31) is provided in the connection network (25) for generation of the control signals (20) and the control signals (20) are relayed via the control line (47, 47a, 47b), also connected to the connection network (25), to the electronically controllable impedance network (11) or the electronically controllable impedance networks (11), respectively (Fig. 3, 4, 5, 7, 8,9).
22. Antenna according to claim 21
    characterized in that
    a diversity processor (30) is provided having a switching processor (31) for generating control signals (20) and in addition to the at least one electronically controllable impedance network (11) at least one controllable electronic switch (19) for selection between ground-related antenna signals (44a) and floating ground antenna signals (44b) (Fig. 8, 9).
23. Antenna according to one of the claims 21, 22
    characterized in that
    the dielectric surface (7) is formed by a plastic trunk lid surrounded by the electrically conductive automotive body as conductive frame (1), and the connection network (25) is provided in the vicinity of the trunk lid attachment (39) connected to the vehicle ground and the ground point (10) forms the high frequency ground of the connection network (25) and is electrically connected to the trunk lid attachment (39) (Fig. 3, 4, 5, 11).
24. Antenna according to claim 23
    characterized in that
    a first connection network (25 a) is provided in the vicinity of the trunk lid attachment (39) on one side and a second connection network (25b) in the vicinity of the trunk lid attachment (39) on the other side of the plastic trunk lid for further diversification of the reception signals and/or for configuration of two simultaneously available reception signals e.g. for diversity receivers having two inputs for in-phase superposition of the signals in the receiver, in connection with a scanning diversity system (Fig. 7, 11).
25. Antenna according to claim 24
    characterized in that
    in addition - e.g. for terrestrial television reception - TV amplifiers (36a, b and 36 b, c) each having a connection with a wire-shaped antenna conductor (38b, c, d, e) are provided in the connection network (25) or the connection networks (25a, b) and, for configuration of their lengths for high-performance TV diversity reception, the electronically controllable impedance networks (11a, b, c) are distributed within the ring structure (5) and include impedance networks (26) enabling the high-performance FM diversity reception in the FM range (Fig. 9).
26. Antenna according to one of the claims 1 to 25
    characterized in that
    the dielectric surface (7) is inserted into a section of the motor vehicle metallic roof (41) and said section is preferably configured as a square and preferably extends over the major part of the width of the roof (Fig. 12).

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