EP1239543B1 - Flat antenna for the mobil satellite communication - Google Patents

Abstract

An antenna for mobile satellite communication disposed on a substantially horizontally oriented conductive base surface having substantially linear conductor parts and an antenna connection point. The conductor parts have a substantially vertical extension portion, substantially horizontal extension portion which, together with the conductive base surface, form a high frequency conducting ring structure. The conductor parts are disposed in a plane, mounted perpendicular to the conductive base surface, and one of the vertical or horizontal extension portions is interrupted to form the antenna connection point. In a further interruption of one of the conductor parts, is provided at least one impedance connection point wired to an impedance. The positions of the impedance connection point and of the antenna connection point as well as the impedance are chosen so that, for the plane standing perpendicular to the conductive base surface, with waves polarized in this plane, the predetermined antenna gain values can be obtained for a predetermined elevation angle of the incident wave.

Description

The invention relates to an antenna for the mobile satellite communication on a substantially horizontally oriented conductive base consisting of substantially linear conductor parts and an antenna connection point. Antennas of this type are known from DE 40 08 505.8. This antenna consists of crossed horizontal dipoles with V-shaped downwardly inclined dipole halves made of linear ladder sections mechanically fixed at 90 degrees to each other and attached to the upper end of a linear vertical conductor mounted on a horizontally oriented conductive base.

In order to generate the circular polarization usually required in satellite communication, the horizontal dipoles, which are inclined downwards in both V-shaped directions, are interconnected electrically via a 90-degree phase network. For satellite antennas depending on the satellite communication system, an antenna gain of constant 3dBi for circular polarization is strictly required in the elevation angle range between 25 and 30 degrees and 90 degrees. With antennas of this design, the antenna gain required in the area of the zenith angle can generally be realized problem-free. In contrast, the required antenna gain in the range of low elevation angle of 20 to 30 degrees is difficult and due to the V-shaped downwardly inclined horizontal dipoles, which naturally require a sufficiently large distance from the conductive base for their function, not - as for the mobile Use required - can be realized with very small height of the antennas.

It is also known to use curved antennas to meet the profit requirements both in the low-elevation angle range and in the case of steep-angle radiation from linear conductors. The most commonly used antenna form today is the Kilgus quadrifilar helix antenna (IEEE Transactions on Antennas and Propagation, 1976, p.238-241). Such antennas often have a length of several wavelengths and are not known as low-profile flat antennas. Even with a low-height antenna specified in EP 0 952 625 A2, the abovementioned gain values in the angular range with low elevation can not be fulfilled.

The invention is therefore based on the object first of all to specify an antenna which allows the ratio of antenna gain in the low elevation range to the antenna gain in the zenith angle range in an azimuthal main plane according to requirements set and which makes it possible by combining a plurality of such antennas a directional diagram according to the profit requirements for To realize the satellite communication with circularly polarized waves at an electrically small height of the antenna.

This object is achieved in an antenna according to the preamble of the main claim by the characterizing features of the main claim and the measures proposed in the other claims.

Antennas according to the invention can be produced in a particularly simple and thus cost-effective manner, in particular in their form of training for satellite communications. Furthermore, they are particularly suitable for use on vehicles due to their structure over a conductive base and their small design height. Another advantage is that it can be extended to the combination antenna for terrestrial communication, which goes hand in hand with the saving of installation space in motor vehicles. A further advantage is that measures can be taken to ensure that in the presence of discontinuities in the conductive base or in their imbalance, such. Roof slope or roof edge, relative to the horizontal, the resulting disturbance of the directional diagram can be largely compensated.

• Fig. 1: Prinzip einer Antenne nach der Erfindung mit einer hochfrequent leitenden Ringstruktur 2, gebildet aus im wesentlichen vertikalen Leiterteilen 4a und im wesentlichen horizontalen Leiterteilen 4b und der leitenden Grundebene 1.
• Fig. 2: Prinzip einer Antenne nach der Erfindung mit einseitiger Auskopplung an der Antennenanschlußstelle 5.
• Fig. 3a: Symmetrische Antenne einer Antenne nach der Erfindung mit den Antennenanschlußstellen 5 und 5' und einem Umsymmetriernetzwerk 9, gebildet aus unsymmetrischen Leitungen 10a und 10b.
• Fig. 3b: Symmetrische Antenne nach der Erfindung mit einem Umsymmetriernetzwerk 9, gebildet aus unsymmetrischen Leitungen 10a und 10b, deren Länge sich um ein ungeradzahliges Vielfaches der halben Betriebswellenlänge unterscheidet.
• Fig. 3c: Symmetrische Antenne nach der Erfindung mit einem Umsymmetriernetzwerk 9 nach dem transormatorischen Prinzip zur getrennten unsymmetrischen Auskopplung der symmetrischen und der unsymmetrischen Spannungen.
• Fig. 4a: Symmetrische Antenne nach der Erfindung, bei der die Antennenanschlußstelle 5 im Bereich der Symmetrieachse 8 der Antenne angeordnet ist und bei der die Signale mittels einer symmetrischen Zweidrahtleitung nach unten geführt sind.
• Fig. 4b: Detail aus Fig. 4a.
• Fig. 4c: Detail aus Fig. 4a, aber mit einer geschirmten Zweidrahtleitung.
• Fig. 4d: Antenne nach der Erfindung ähnlich Fig. 4a, jedoch mit zwei Koaxialleitungen an Stelle der Zweidrahtleitung und mit einem Umsymmetriernetzwerk 9 nach dem transformatorischen Prinzip zur getrennten unsymmetrischen Auskopplung der symmetrischen und der unsymmetrischen Spannungen.
• Fig. 5: Antenne nach der Erfindung mit Bemassungsangaben und mit einem Anpaßnetzwerk 17.
• Fig. 6a: Antenne für Zirkularpolarisation, gebildet aus zwei Antennen nach der Erfindung in aufeinander senkrecht stehenden Ebenen, deren Ausgangssignale über ein 90-Grad Phasendrehglied 18 in einer Summationsschaltung 19 zusammengefaßt sind.
• Fig. 6b: Beispiel für ein Streifenleitungslayout für die Antenne nach Fig. 6a.
• Fig. 6c: Räumliche Darstellung der Antenne für Zirkularpolarisation.
• Fig. 7: Antenne für Zirkularpolarisation, gebildet aus drei Antennen nach der Erfindung in drei Ebenen, die azimutal in 120°-Winkeln angeordnet sind, deren Ausgangssignale über 120-Grad Phasendrehglieder 18 in einer Summationsschaltung 19 zusammengefaßt sind.
• Fig. 8: Antenne für Zirkularpolarisation nach Fig. 7, bei der der vertikale Leiter 4a' im Symmetriepunkt der Anordnung entfällt.
• Fig. 9a: Antenne nach der Erfindung mit einem weiteren Anschlußtor Tu zur Auskopplung einer unsymmetrischen Spannung.
• Fig. 9b: Prinzip der Signalauskopplung bei einer erfindungsgemäßen Antenne nach Fig. 9a.
• Fig. 10a: Antenne für Zirkularpolarisation, gebildet aus zwei Antennen nach der Erfindung in aufeinander senkrecht stehenden Ebenen, deren Ausgangssignale über ein 90-Grad Phasendrehglied 18 in einer Summationsschaltung 19 zusammengefaßt sind mit einem weiteren Anschlußtor Tu zur Auskopplung einer unsymmetrischen Spannung.
• Fig. 10b: Prinzip der Signalauskopplung bei einer erfindungsgemäßen Antenne nach Fig. 10a.
• Fig. 11: Variation der Richtdiagramme bei Änderung des Werts und des Charakters (induktiv oder kapazitiv) der Impedanz 7 bei einem Beispiel einer erfindungsgemäßen Antennen.
• Fig. 12a: Elevationsdiagramm eines Beispiels einer erfindungsgemäßen Antenne
• Fig. 12b: Dreidimensional dargestelltes Diagramm einer erfindungsgemäßen Antenne.
• Fig. 13: Elevationsdiagramm eines Beispiels einer schielenden erfindungsgemäßen Antenne.
• Fig. 14a: Ausbildung einer flächenhaften Dachkapazität 31 in Form eines durch die Impedanz 7 unterbrochenen Halbellipsoids parallel zur Ebene 1
• Fig. 14b: Wie Fig. 14a, jedoch mit leiterförmiger Ausbildung des Halbellipsoids
• Fig. 15a: Draht- oder streifenförmige Leiterteile 32 mit wesentlicher horizontaler Ausdehnung 4b in der Ebene 30 parallel zur Ebene 1
• Fig. 15b: Wie Fig. 15a, jedoch mit flächenhaft gestalteten Leiterteilen 4b vorzugsweise in gedruckter Leitertechnik
• Fig. 16: Ähnliche Ausführungsform wie Fig. 15b, ebenfalls in gedruckter Leitertechnik
• Fig. 17a-c: Erklärung der prinzipiellen Wirkungsweise erfindungsgemäßer Antennen mit streng symmetrischem Aufbau im Hinblick auf die kapazitiven Koppeleffekte
• Fig. 18a: Erfindungsgemäße Antenne für Zirkularpolarisation und streng symmetrischem Aufbau mit dreiecksförmigen Dachkapazitäten 31 und zur Erläuterung der Strompfade
• Fig. 18b: Antenne mit ringförmiger Zentralstruktur 37 und Koppelkapazitäten 34
• Fig. 19: Erfindungsgemäße Antenne ähnlich Fig. 18b, jedoch mit zusätzlichem vertikalen Antennenleiter 20 in der vertikalen Symmetrielinie 8
• Fig. 20: Kombination aus Dachkapazitäten 31, welche auf einem dielektrischen Körper von der Form eines Pyramidenstumpfs geeignet ausgebildet sind.
• Fig. 21a: Ähnlich Fig. 10b, jedoch mit weiteren Anschlusstoren 40a bis 40c zur Auskopplung unsymmetrischer Spannungen für weitere Funkdienste
• Fig. 21b: Wie Fig. 21a, jedoch mit frequenzselektiven Entkopplungsnetzwerken 42 in den Anschlusstoren T1a, T1b, T2a und T2b
• Fig. 22: Prinzipieller möglicher Aufbau einer erfindungsgemäßen Antenne für Satellitenfunk und mehrere terrestrische Funkdienste

The invention will be described in more detail below with reference to FIGS. Show it:

• Fig. 1: Principle of an antenna according to the invention with a high-frequency conductive ring structure 2, formed of substantially vertical conductor parts 4a and substantially horizontal conductor parts 4b and the conductive ground plane. 1
• Fig. 2: Principle of an antenna according to the invention with unilateral decoupling at the antenna connection point. 5
• Fig. 3a: Symmetrical antenna of an antenna according to the invention with the antenna terminals 5 and 5 'and a Umsymmetriernetzwerk 9, formed of unbalanced lines 10a and 10b.
• Fig. 3b: Symmetrical antenna according to the invention with a Umsymmetriernetzwerk 9, formed of unbalanced lines 10a and 10b, whose length differs by an odd multiple of half the operating wavelength.
• Fig. 3c: Symmetrical antenna according to the invention with a Umsymmetriernetzwerk 9 according to the transormatory principle for the separate unbalanced extraction of the balanced and the unbalanced voltages.
• Fig. 4a: Symmetrical antenna according to the invention, in which the antenna connection point 5 is arranged in the region of the symmetry axis 8 of the antenna and in which the signals are guided by means of a symmetrical two-wire line down.
• Fig. 4b: Detail of Fig. 4a.
• Fig. 4c: Detail of Fig. 4a, but with a shielded two-wire line.
• Fig. 4d: Antenna according to the invention similar to Fig. 4a, but with two coaxial lines instead of the two-wire line and with a Umsymmetriernetzwerk 9 according to the transformer principle for the separate unbalanced extraction of the balanced and the unbalanced voltages.
• Fig. 5: Antenna according to the invention with dimensions and with a matching network 17th
• Fig. 6a: Antenna for circular polarization, formed from two antennas according to the invention in mutually perpendicular planes whose output signals are combined via a 90-degree phase shift member 18 in a summing circuit 19.
• Fig. 6b: Example of a stripline layout for the antenna of Fig. 6a.
• Fig. 6c: Spatial representation of the antenna for circular polarization.
• Fig. 7: Antenna for circular polarization formed by three antennas according to the invention in three planes, which are arranged azimuthally at 120 ° angles, whose output signals over 120-degree phase shifters 18 are combined in a summation circuit 19.
• FIG. 8: Antenna for circular polarization according to FIG. 7, in which the vertical conductor 4a 'in the symmetry point of the arrangement is omitted.
• Fig. 9a: antenna according to the invention with a further connection port Tu for coupling an unbalanced voltage.
• Fig. 9b: principle of the signal extraction in an antenna according to the invention of Fig. 9a.
• Fig. 10a: Antenna for circular polarization formed by two antennas according to the invention in mutually perpendicular planes whose output signals via a 90-degree phase shifter 18 are combined in a summation circuit 19 with a further connection port Tu for coupling an unbalanced voltage.
• 10b: Principle of signal extraction in an antenna according to the invention according to FIG. 10a.
• 11: Variation of the directional diagrams when the value and the character (inductive or capacitive) of the impedance 7 change in an example of an antenna according to the invention.
• Fig. 12a: elevation diagram of an example of an antenna according to the invention
• 12b shows a three-dimensional diagram of an antenna according to the invention.
• Fig. 13: elevation diagram of an example of a squinting antenna according to the invention.
• FIG. 14 a: Formation of a planar roof capacitance 31 in the form of a semi-ellipsoid interrupted by the impedance 7, parallel to the plane 1
• Fig. 14b: Like Fig. 14a, but with a ladder-shaped formation of the semi-ellipsoid
• FIG. 15 a: Wire or strip-shaped conductor parts 32 with a substantial horizontal extension 4 b in the plane 30 parallel to the plane 1
• Fig. 15b: As in Fig. 15a, but with areal shaped ladder parts 4b preferably in printed wire technology
• Fig. 16: Similar embodiment as Fig. 15b, also in printed circuit technology
• 17a-c: Explanation of the principle of operation of antennas according to the invention with a strictly symmetrical design with regard to the capacitive coupling effects
• 18a: Antenna according to the invention for circular polarization and strictly symmetrical construction with triangular roof capacities 31 and for explaining the current paths
• FIG. 18b: Antenna with annular central structure 37 and coupling capacitances 34
• FIG. 19: Antenna according to the invention, similar to FIG. 18b, but with additional vertical antenna conductor 20 in the vertical symmetry line 8
• Fig. 20: Combination of roof capacitances 31 which are suitably formed on a dielectric body of the shape of a truncated pyramid.
• FIG. 21 a: Similar to FIG. 10 b, but with further connection gates 40 a to 40 c for coupling unbalanced voltages for further radio services
• Fig. 21b: As Fig. 21a, but with frequency-selective decoupling networks 42 in the connection gates T1a, T1b, T2a and T2b
• Fig. 22: Principal possible structure of an antenna according to the invention for satellite radio and several terrestrial radio services

Fig. 1 shows the basic shape of an antenna according to the invention consisting of a formed together with the conductive base 1 high frequency conductive ring structure 2 with ladder parts with essential horizontal extension 4b and ladder parts with significant vertical extent 4a within a plane 0, which on the conductive base is vertical. An essential function according to the present invention takes in this case the impedance 7, which is introduced in an interruption point of the high-frequency conducting ring structure 2 into the impedance connection point 6 with the first impedance connection point 6a and the second impedance connection point 6b. If an electromagnetic wave polarized in the plane 0 occurs at a certain elevation angle 81, the horizontal electrical field components are mainly taken up by the conductor parts with substantial horizontal expansion 4b and - correspondingly - the vertical electric field components mainly by the conductor parts with substantially vertical Extension 4a. With a suitable position of the antenna connection point 5 in an interruption point of the ring structure 2 and with suitable positioning of the impedance 7 within the ring structure 2, a vertical diagram can be set with a desired superposition of the recording of vertical and horizontal electric field components.

From US Pat. No. 3,427,624, there in FIG. 2, an antenna with a ring structure is known in which, with the aid of tunable capacitors, which are connected in the longitudinal train of the ring structure, a resonance-like impedance matching can be tuned in a wide frequency range. An influence of the directional diagram with the help of these capacitors is not provided. In contrast to the present invention, the ring structure of the antenna in Fig. 2 is not broken in the document D1 to provide an antenna connection point. The creation of the Antennenanschlnsspunkts happens there at the end of an additional antenna part in the form of a "feed wire 5", which is coupled in parallel to the ring structure.

The design of the predetermined ratio of the antenna gain in the zenith angle range to the antenna gain in the range of low elevation angles is the basic requirement Thus, two identical impedances 7, which are also positioned symmetrically to the vertical line of symmetry 8, and a mirrored to the first antenna connection point 5 introduced antenna connection point 5 'at the conductive base 1 has. The coupling of the ring structure 2 to the conductive base 1 allows, as shown in Fig. 3b, the advantageous embodiment of a Umsymmetriernetzwerks 9, which can be realized for example with the aid of a λ / 2 detour line of the signals. The decoupling of the unbalanced receiving voltages Uu, which form symmetrically with respect to the conductive base area 1, whose direction is indicated by arrows in the figures, is effected by simple parallel connection of the unbalanced lines in FIG. 3b whose lengths differ by λ / 2. The combined symmetrical receive voltage -Us is available at the collection point 11 in FIG. 3b.

Such Umsymmetriernetzwerk 9 can be performed very advantageous and inexpensive in printed microstrip line technology. With this arrangement, the vertical diagrams shown in FIG. 11 can be produced in the plane 0 if the design of the impedance 7 is different. The positioning of the impedance 7 within the ring structure 2 can be freely selected within wide limits, with a stretched conductor length for the section 16 of λ / 4 marked in FIGS. 3a and 3b proving particularly favorable. This applies in particular with regard to the antenna impedances effective at the antenna connection points 5, which should be suitable in particular with regard to an easily realizable balancing network 9 by line circuits. The setting of the appropriate vertical diagram, however, can be done within wide limits for different lengths of the section 16 by appropriate choice of the impedance 7. In a preferred transverse dimension 15 of slightly less than half a wavelength, the directional diagrams shown in FIG. 11 can be achieved at a height 14 of less than a quarter wavelength. In order to overcome the drawback of prior art satellite communication antennas, it is necessary to increase the radiation in the range of low elevation angles compared to the radiation in the zenith angle range. This is done according to the invention by designing the impedance 7 as a capacitance. This causes the increase in the radiation in the range of low elevation angle with increasing reactance, that is, decreasing capacitance value. This is indicated by diagrams D3, D2 and D1 in Fig. 11 for decreasing capacitance values. If the impedance 7 is implemented as an inductance instead of a capacitance, then the elevation diagrams denoted by D4 and D5 result in Fig. 11. These have the property to hide an angular range at medium elevation largely. The inductance value of the directional diagram D5 is chosen larger than for the directional diagram D4. For satellite communication, therefore, apart from special cases for special applications, due to the above-described requirement for an antenna according to the invention, capacities are used as impedance 7. For combining several such antennas into a circularly polarized satellite communication antenna, this property of the antenna is essential.

Advantageous is the additional availability of the unbalanced voltages Uu at the antenna connection points 5, which is used in Fig. 3c, that in a summation circuit 19 in addition to a Umsymmetriernetzwerk 9 for coupling the unbalanced receive voltages Uu a power divider 21 for coupling the symmetrical receiving voltages Us available is. Thus, at the collection point for symmetrical voltages 11a and at the collection point for asymmetrical voltages 11b in FIG. 3c, both unbalanced reception voltages Uu and symmetrical reception voltages Us can be coupled out separately from one another.

A further advantageous decoupling of the symmetrical voltage Us can, as in FIG. 4 a, take place at an antenna connection point 5 arranged in the vertical symmetry line 8. For this purpose, a two-wire line 24 is connected to the first antenna connection point 5a and the second antenna connection point 5b in FIG. 4b (detail from FIG. 4a) and guided in the vertical line of symmetry 8 to the conductive base 1, in the vicinity of which a line connection point 25 is designed. There, between the end points of the two-wire line 24, the voltage -Us proportional to the symmetrical receiving voltages Us and, between each end point of the two-wire line 24 and the conductive base 1, the voltage -Uu proportional to the asymmetrical receiving voltages Uu are formed.

In a further advantageous embodiment of the invention, as in Fig. 4c, the two-wire line 24 can be replaced by a shielded two-wire line 23, the shield conductor is connected to the conductive base 1. As a result, a more favorable decoupling of the voltage -Uu at the conductive base area 1 is made possible. In a further advantageous embodiment, the shielded two-wire line 23 can be carried out in a simple manner by means of two coaxial lines 22 guided in parallel, as in FIG. 4d, their screens are connected to the conductive base 1. With the aid of the power divider 21, the voltages -Us and -Uu, as described above, can be coupled out separately with the arrangements of FIGS. 4b, 4c and 4d.

In a particularly easy to manufacture antenna according to the invention, as shown in Fig. 5, the ring structure 2 is configured substantially rectangular. Realized antenna shapes with a section 16 of about ¼ λ, a transverse dimension 15 of about 1/3 λ and a height 14 of about 1/6 λ have given sufficiently small losses for required directional diagrams. A realized antenna according to the invention for frequencies around 2.3 GHz has e.g. only a height 14 of 2cm with a transverse dimension 15 of 4.5 cm. With a smaller overall height, the demands on the directional diagram can be fulfilled when a corresponding capacitance value for the impedance 7 is selected, but increasing losses are to be expected. The losses occurring in the downstream matching network 17 thus increase with a smaller antenna height.

An essential advantageous embodiment of the invention consists in the combination of several antennas according to Fig. 5 to a satellite communication antenna for circular polarization. For this purpose, in a particularly advantageous embodiment, two antennas whose planes 0 are perpendicular to each other, combined, each antenna having a Umsymmetriernetzwerk 9 and a matching circuit 17 as in Fig. 6a and Fig. 6c. At the output of the matching circuit 17, the voltage for circular polarization Uz with the aid of a phase shifter 18 and a summing circuit 19 is formed. The latter are realized in Fig. 6c by means of a parallel connection of lines whose length differs by λ / 4. The matching circuit 17 can be advantageously realized by printed dummy elements as shown in Fig. 6b. The lines for balancing are designed as lines 10a, b, the network as adaptation as series or spur lines 17 and for interconnection and 90 degree phase rotation as a line 18 each printed.

With antennas of this embodiment, a suitable elevational diagram of Fig. 11 is set by the character of the diagrams D2 and D3 for the single antenna of Fig. 5. After the interconnection according to FIG. 6c, the total diagram required for circular polarization according to FIG. 12a (section azimuthal angle = const.) And FIG. 12b (spatial diagram) are set therefrom.

If the conductive base is skewed, e.g. In the case of a curved vehicle roof in the edge region of a window, the asymmetry of the conductive base area 1 and the inclination can be compensated for by different capacitance values in the individual antenna branches. This corresponds to a squint of the diagram. A squinting diagram adjustable with antennas according to the invention with a squint angle of approximately 15 degrees with respect to the zenith angle is shown by way of example in FIG. 13.

In a further advantageous embodiment of the invention, N antennas can be arranged rotationally symmetrically at an angular distance of 360 / N degrees to a vertical symmetry line 8 as in FIG. 7. Accordingly, phase shifters 18 are provided with a respective phase rotation angle of 360 / N degrees, whose output signals are combined in the summation circuit 19 and are available at the collection point 11. With regard to the design of the impedance 7, the above rules apply. The circular healing of the azimuthal directional diagram can be further improved by choosing sufficiently large values of N. The rotational symmetry of such an arrangement allows the elimination of the vertical conductor 4a ', as in Fig. 8 to.

In a further advantageous embodiment of the invention, the satellite communication antenna is extended to a combination antenna for which the additional terrestrial communication with vertical polarization at a frequency deviating from the satellite radio frequency. This is very advantageous associated with a saving of space in motor vehicles.
In a symmetrical antenna constructed of two antennas according to the basic form of this invention as in FIG. 9a, along the symmetry line 8 is a vertical antenna conductor 20 which is connected at one end to a horizontal part of the ring structure 2 and between its lower end and the conductive base area 1 a connection port Tu is formed to form an unbalanced voltage Uu. In this case, the conductor parts with a horizontal extent 4b act as a roofing capacitance for the vertical antenna conductor 20. The symmetrical voltages are tapped from the ring structure 2 at the corresponding gates T1a and T1b. The matching network 29 in FIG. 9b is used for the frequency-selective adaptation of the connection gate Tu for the frequency of the terrestrial radio service present impedance to the characteristic impedance of conventional coaxial cables. At the output of this matching network 29 is the voltage Uu proportional to Uu.

In order not to interfere with the satellite service, the matching network 29 is advantageously designed so that the port gate Tu is loaded at the satellite radio frequency with a reactance or particularly advantageous with a short circuit or no load. The symmetry of the arrangement can advantageously be used for decoupling the connection doors Tu from the connection gates T1a, T1b when they are connected to the balancing network 9. This is particularly important for the protection of the satellite service if the terrestrial communication is bidirectional. With remaining residual unbalance, it is advantageous to improve the decoupling of the satellite service to make the Umsymmetriernetzwerk 9 such that the ports T1a and T1b are loaded at the frequency of the terrestrial radio service with a short circuit.

In Fig. 10a the complete satellite communication antenna for circular polarization with the vertical antenna conductor 20 is shown. At the connection ports T2a and T2b of the antenna rotated by 90 degrees with respect to the antenna with the ports T1a, T1b, a balancing network 9 with subsequent adaptation circuit 17 as shown in FIG. With regard to the loading of the ports T2a and T2b at the frequency of the terrestrial communication service for the protection of the satellite service, the above statements apply.

In the advantageous embodiment of the invention, the conductor parts are designed with a substantial horizontal extension 4b to form a roofing capacity 31 with a curved surface in the form of a semi-ellipsoid and the boundary is guided in a surface 30, which in one of its dimensions substantially perpendicular to the plane 0 and thus oriented substantially parallel to the plane 1. This is illustrated by way of example in FIGS. 14a and 14b. By suitable choice of size and shape of the effective as a roof capacitance 31 curved surface in conjunction with the appropriate dimensioning of the impedances 7, both the vertical diagram and the present at the base of the ladder parts with essential vertical extension 4a footpoint impedances can be set as desired. In this case, the conductor parts with a substantial horizontal extent 4b for the formation of the roof capacity 31 of wire or strip-shaped conductors 32 may be formed, as indicated in Fig.14b and be designed as a grid structures. For a particularly easily formed embodiment of a roofing capacitor 31, it is completely disposed in the surface 30 as a plane parallel to the conductive base 1 (Figure 15a) and preferably formed in printed wire technology, as shown in Figures 15a and 15b. This results in the particularly advantageous property that both the roof capacitance 31 and the most capacitively executed impedances 7 can be made highly accurate and reproducible and thus both the directional diagram and the above-mentioned Fußpunktsimpedanzen in series production can be ensured with small variations. Another embodiment of the invention in printed technique is shown in FIG. 16.

In a further advantageous embodiment of the invention, in the ring structure 2, the conductor parts with essential horizontal extension 4b and a plurality of impedances 7,7 'are formed such that with respect to the level 0, in which the conductor parts are guided with a significant vertical extent 4a also with respect to Impedance values of the impedances 7,7 'symmetrical arrangement is given. In this case, the symmetry of the arrangement should also be given with respect to a symmetry plane 33 oriented perpendicular to both the base surface 0 and the base plane 1. Such arrangements are shown in Figures 17a, 17b and 17c. To explain the operation of an antenna according to the invention, as shown in Fig. 17c, the ring structure 2 in Fig. 17a should first be considered. Such a ring structure contains the capacitances 7, 7 ', whereby, given equality of the capacitances lying symmetrically to the vertical symmetry line, the frame formed thereby is also electrically symmetrical. Also, capacitances between ladder sections of substantial horizontal extent 4b and the surrounding space do not disturb this symmetry. Thus, the arrangement in Fig. 17a represents an antenna designed according to the main claim of the invention and additionally having the property of symmetry. To better identify the operation of this arrangement, the level 0, in which ladder parts are introduced with significant vertical extent 4a and the plane of symmetry 33 shaded located.

By the described coupling of a Umsymmetriernetzwerks 9, as shown for example in Fig. 9b, thus a voltage Us can be coupled out of the connection ports T1a and T1b from the symmetrical antenna arrangement. To explain the Operation is noted that in the plane 33 in Fig. 17a initially no ladder parts are introduced with significant vertical extent 4a. According to the nomenclature in Fig. 3a, the impedances marked with 7,7 'on one side of the vertical line of symmetry 8 in Figures 17a to 17c 7 and marked on the other side of the line of symmetry 8 with 7'. Thus, all effective impedances in Fig. 17a are additionally indicated at 1 with respect to the gates labeled T1a and T1b with corresponding indexes 7,7 'for placement with respect to the plane of symmetry 33 and common action on the gates T1a and T1b. The capacitances not shown in FIG. 17a, which are located in the plane of symmetry 33, have no effect on the gates T1a and T1b. In Fig. 17b, the ladder parts having a substantial vertical extent 4a with respect to the goals T1a, T1b are omitted for the sake of understanding. With a constant arrangement of all blind elements 7 described in FIG. 17a, a ring structure 2 with the associated gates T2a and T2b is formed in the plane of symmetry 33. The designations for the dummy elements 7 are accordingly related to these two gates in accordance with the nomenclature introduced in FIG. 17a. When the two ring structures 2 in FIGS. 17a and 17b are combined to form the complete arrangement shown in FIG. 17c, two ring structures 2 which are completely symmetrical with respect to the vertical symmetry line 8 are obtained according to the invention. It can be seen that an arrangement as shown in FIG. 18a is, with a suitable choice of the dimensions of the roof capacitors 31 shown there, which form coupling capacitances, as shown in Fig. 17c, is also designed according to the invention, if the coupling capacitances by suitable design of the roof capacitances according to the invention effective impedances 7 with the required size form.

The current arrows for the currents I1 and I2 indicated in FIG. 18a indicate the principal current flow of the two frames 2. The current arrows show the way in which the impedance network consisting of impedances 7 works together for both frame parts and in which of the impedances 7 the currents I1 and I2 are uniform and in which they are superimposed in opposite directions. In Fig. 18a an example of a wiring of the four gates T1a, T1b, T2a, T2b is given, which allows to make in the described manner an antenna according to the invention for the circularly polarized radiation. In the following, exemplary embodiments for an antenna of this type are listed in FIGS. 18b, 19 and 20. In Fig. 18b, the two frames are in the vicinity of the vertical Symmetry line 8 coupled via a conductive central structure 37 via preferably printed coupling capacitances. The correspondingly designed roof capacities 31 with their coupling capacitances 34 to one another and such capacitances to the ring-shaped central structure 37 make it possible to dimension the antenna with regard to a desired directional diagram. 19, the annular central structure 37 of the antenna in FIG. 19 permits the introduction of a vertical antenna conductor 20, which is suitably coupled to the ring-shaped central structure 37 to form a desired impedance at the connection port Tu with a radiator coupling capacitance 38 which can be configured in a simple manner. In a further example of an antenna according to the invention, a combination of roof capacitances 31 which are suitably formed on a dielectric body of the shape of a truncated pyramid is arranged in FIG. 20, so that the suitable directional diagram is established via the coupling and space capacities.

In a further very advantageous embodiment of the invention, the antenna is designed for the coordinated and simultaneous reception of circularly polarized satellite radio signals and of vertically polarized radio signals emitted by terrestrial radio stations in a frequency closely adjacent high-frequency band. For such an application, a frequency-selective decoupling of the terrestrial radio service from the satellite service is not possible due to the small frequency spacing. The symmetrical embodiment of the antennas described above, on the other hand, has complete decoupling between the vertical antenna conductor 20 and the output for receiving the circular polarization. Thus, the system does not rely on narrow band frequency selection between the two radio services, and the terrestrial broadcast signal and the satellite broadcast signal can be independently received. A mutual damping by the power extraction at the other gate is not given by. Due to the symmetry of the antenna, this property is thus also given for even-frequency signals such that the reception of vertically polarized electric field components on vertical antenna conductor 20 does not affect the reception of vertically polarized electric field components at the port with respect to the output for receiving the circular polarization. This situation is given in the antennas of Figures 10a, 10b, 19, 20 and 22.

In a further advantageous embodiment of the invention, an antenna for the additionally combined bidirectional radio operation with vertically polarized terrestrial radio stations is shown in FIG. In this case, the vertical antenna conductor 20 is additionally used for at least one bidirectional radio operation with vertically polarized terrestrial radio stations. The radiator length 43 of the vertical antenna conductor 20 for the lowest frequency radio service is advantageously chosen to be sufficiently large. In the case of a required frequency selective shortening of the electrically effective radiator length 43 for higher radio channel frequencies, as shown in Figures 21a and 21b, advantageously in the Längszug the vertical antenna conductor 20 interruption points with suitable dummy elements 41 for designing the vertical diagram and the Fußpunktsimpedanz for this Frequency inserted.

In Fig. 21a, the block diagram of such a combination antenna is shown. In order to effect the impedance matching for the various radio services, corresponding matching networks 29a, 29b, 29c with outputs 40a, 40b, 40c are advantageously used to connect the corresponding radios. In order to separate the impedance effects and the signals in the various frequency ranges, the inputs of the matching networks 29a, 29b, 29c are respectively connected to the common connection port Tu via a frequency-selective separation circuit 39a, 39b, 39c, respectively; the matching conditions at the port gate Tu in the radio frequency channels of the various radio services are influenced as little as possible by each other.

To avoid radiation-induced coupling between the connection port Tu of the vertical antenna conductor 20 and the connection ports T1a, T1b, T2a, T2b of the ring structures 2, decoupling networks 42 are advantageously used in the vicinity of the foot points of the conductor parts with a substantial vertical extent 4a. These are designed so that they act for signals on the frequency of bidirectional radio operation with vertically polarized radio stations blocking, but are permeable to the frequency of the circularly polarized satellite radio signal. This causes in a beneficial manner that the impedances present at the gates T1a and T1b via the balancing network 9 do not cause any disturbing effect on their frequency of a bidirectional radio service via their active component or undesired reactances on such a frequency.

SdarZusL.doc List of terms

• Level 0
• conductive base 1
• Ring structure 2
• Ladder parts with substantial vertical extension 4a
• Ladder parts with essential horizontal extension 4b
• Antenna connection points 5, 5 '
• first antenna connection point 5a, 5a '
• second antenna connection point 5b, 5b '
• Impedance connection point 6, 6 '
• first impedance connection point 6a, 6a '
• second impedance connection point 6b, 6b '
• Impedance 7, 7 '
• vertical symmetry line 8
• symmetrical reception voltages Us
• unbalanced receiving voltages Uu
• Balancing network 9
• Unbalanced lines 10a, b
• Collection point 11
• Collection point for symmetrical voltages 11a
• Collection point for unbalanced voltages 11b
• Symmetry point 12
• Symmetrical line 13
• Height 14
• Transverse dimension 15
• Section 16
• Matching circuit 17
• Phase turn member 18
• Summing circuit 19
• vertical antenna conductor 20
• Power divider 21
• Coaxial line 22
• Shielded two-wire line 23
• Two-wire line 24
• Line connection point 25
• Connection for circular polarization 26
• Printed circuit board 27
• Detour line 28
• Matching Network 29
• Area 30
• Roof capacity 31
• Wire or strip conductors 32
• Symmetry plane 33
• Coupling capacities 34
• planar conductor structures (35)
• Separating columns (36)
• Central structure (37)
• Spotlight length (43)
• Radiator coupling capacity (38)
• Frequency-selective separation circuits (39)
• Output (40)
• Blind elements (41)
• Decoupling network (42)

• Wave incidence 80
• Elevation angle 81
• Connection door T1a
• Connection door T1b
• Connection port T2a
• Connection port T2b
• Connection door Tu
• symmetrical voltages Us
• unbalanced voltages Uu voltage for circular polarization Uz

Claims (37)

1. Antenna for mobile satellite communication on a substantially horizontally oriented conductive base surface (1), comprising substantially linear conductor parts (4) having substantially vertical extent (4a) and having substantially horizontal extent (4b), as well as an antenna connection point (5), whereby

   - the conductor parts (4a and 4b) are disposed substantially in a plane (0) standing perpendicular to the conductive base surface (1);

   - the conductor parts (4a and 4b) form a high-frequency conductive ring structure (2) together with the conductive base surface (1),

   characterized by the following characteristics:

   - the ring structure (2) is interrupted by the antenna connection point (5) and by at least one impedance connection point (6) wired to an impedance (7), in the region of the conductor parts (4a and 4b),

   - the establishment of the position of the interruptions for the impedance connection point (6) and for the antenna connection point (5), as well as the establishment of the values for the impedance (7), in each instance, are the measures for configuring the antenna gain for different elevation angles (81).
2. Antenna according to claim 1,
   characterized in that
   the antenna connection point (5) is formed at the foot point of a conductor part having substantially vertical extent (4a), together with a first antenna terminal (5a) at the lower end of this conductor part, and a second antenna terminal (5b) at a point adjacent thereto on the conductive base surface (1), and the position of the impedance connection point (6) and a reactance as the impedance (7) are selected in such a way that the desired asymmetry of the radiation characteristic with respect to the zenith is formed herewith, while at the same time the guide values at low elevation angles are also sufficient (Fig. 2).
3. Antenna according to claim 1 and 2,
   characterized in that
   the ring structure (2) is formed symmetrically with respect to a symmetry line (8) standing vertically on the conductive base surface (1) and thus, in addition to the first antenna connection point, a further antenna connection point (5') disposed symmetrically relative thereto is provided at the lower end of the other conductor part impacting the conductive base surface (1), and also a further impedance connection point (6') with identical impedance (7') disposed symmetrically relative to the first is provided, and the wiring of the antenna connection points (5') is chosen such that symmetrical voltages Us are established there (Fig. 3a).
4. Antenna according to claim 3,
   characterized in that
   there is provided, for wiring the antenna connection points (5, 5'), an asymmetrizing network (9), at the output of which the symmetrical voltages Us formed symmetrically relative to the base surface (1) are available in combined asymmetrical form at a collection point (11) (Fig. 3a).
5. Antenna according to claim 4,
   characterized in that
   the asymmetrizing network (9) comprises two asymmetrical lines (10a, b) with identical characteristic wave impedance, each of which lines is connected on the input side to an antenna connection point (5), and which are connected in parallel at the output, and the lengths of which are chosen such that their electrical lengths differ from one another by an odd multiple of half the operating wavelength (Fig. 3b).
6. Antenna according to one of claims 2 to 5,
   characterized in that
   the ring structure (2) has rectangular shape and, in the interest of sufficient antenna gain values at low elevation angles (81) of the wave incidence (80), in combination with the requirement of a particularly low overall height (14), the size chosen for the cross dimension (15) is not substantially smaller than one half operating wavelength (Fig. 5).
7. Antenna according to one of claims 2 to 6,
   characterized in that
   the impedance or the impedances (7) are constructed as capacitors, whose capacitance is adjusted according to the requirement of the antenna gain values to be achieved at the predesignated elevation angles of the wave incidence (81) (Fig. 1, Fig. 5).
8. Antenna according to one of claims 2 to 7,
   characterized in that
   in order to achieve an antenna impedance which, at the antenna connection point (5), is favorable with respect to configuration of the asymmetrizing network (9), one quarter wavelength is chosen as a rough guide value for the straight length (16) of the portion of the conductor part (4b) with substantially vertical extent between the antenna connection point (5) and the position of the impedance (7) (Fig. 3a, Fig. 5).
9. Antenna according to one of claims 4 to 8,
   characterized in that
   a low-loss matching circuit (17) is connected downstream from the collection point (11) in order to transform the complex impedance present at the collection point (11) to a real impedance that can be constructed as a line-type characteristic wave impedance (Fig. 5).
10. Antenna for circular polarization,
    characterized in that
    two identical antennas according to claims 4 to 9 are provided, the substantially linear conductor parts (4) of which are routed in orthogonal planes (0) and the output signals of which are combined via a 90-degree phase-rotation element (18) in a summation circuit (19) (Fig. 6a, 6c).
11. Antenna according to claim 10,
    characterized in that
    both antennas are attached on a conductive base surface (1) configured as a printed circuit board (27), and the asymmetrizing network (9) of both antennas is designed as a micro-strip line with a length of one half wavelength, while the matching circuit (17) is made from reactive elements on this printed circuit board (27), and the 90-degree phase-rotation element (18) is constructed as a printed phasing line (28) with matching characteristic wave impedance, and the summation circuit (19) is constructed as a simple parallel circuit of printed lines (Fig. 6b).
12. Antenna according to one of claims 4 to 9,
    characterized in that
    N identical antennas are provided, the substantially linear conductor parts (4) of which are respectively routed in a plane (0), and the planes (0) are respectively spaced apart from one another by the azimuth angle of 360°/N, so that a rotationally symmetrical arrangement around a vertical symmetry line (8) is obtained in such a manner that a vertical conductor (4a') is present in this symmetry line as the conductor part having substantially vertical extent (4a) that is common to all N antennas, and the output signals of the antennas are respectively combined via phase-rotation elements (18), whose electrical phase angle corresponds identically to the associated azimuthal angular spacing of the associated plane (0), in a summation circuit (19) (Fig. 7).
13. Antenna according to claim 12,
    characterized in that
    the vertical conductor (4a'), on the basis of which rotational symmetry of the arrangement results, is dispensed with (Fig. 8).
14. Antenna according to one of claims 1 to 11,
    characterized in that
    the ring structure (2) is formed symmetrically with respect to a symmetry line (8) standing vertically on the conductive base surface (1), and the antenna connection point (5) at the symmetry point (12) is formed symmetrically with respect to the symmetry line (8) and, in addition to a first impedance connection point (6), a further impedance connection point (6') with identical impedance (7) is provided symmetrically relative to the first with respect to symmetry line (8), and the wiring of the antenna connection point (5) is chosen such that voltages ~Us symmetrical with respect to the symmetry point (12) are established there (Fig. 4a, 4b).
15. Antenna according to claim 14,
    characterized in that
    two straight conductors routed parallel to one another along the symmetry line (8) are connected as a two-wire line (24) to the antenna connection point (5), and a line connection point (25) is formed at the end of the two-wire line (24) adjacent to the conductive base surface (1), in such a way that the asymmetrical voltage ~Uu is present between each conductor end and the conductive base surface (1), and the symmetrical voltage -Us is present between the two conductor ends (Fig. 4b).
16. Antenna according to claim 15,
    characterized in that
    the two-wire line (24) is designed as a shielded two-wire line (23), whose shield is connected at the other end of the line to the base surface (1) (Fig. 4c).
17. Antenna according to claim 16,
    characterized in that,
    instead of the shielded two-wire line (23), two coaxial lines routed parallel to one another are routed, each inner conductor of which is connected at each end of the line to a terminal of the antenna connection point (5), and the outer conductor of which is connected to the base surface (1), so that the symmetrical voltages ~Us are present at this point between the inner conductors, and the asymmetrical voltages ~Uu are present between each inner conductor and the base surface (1) (Fig. 4d).
18. Antenna according to one of claims 4 and 14 to 17,
    characterized in that
    a coupling-out network (9a) for coupling out asymmetrical voltages -Uu is provided in combination with the asymmetrizing network (9) and, on the input side, is connected to the antenna connection points (5) or to the line connection point (25), at the output of which coupling-out network there are present, in combined asymmetrical form, at a first collection point (11b), the asymmetrical voltages ~Uu formed asymmetrically relative to the base surface (1) on the input side, and the symmetrical voltages ~Us formed symmetrically relative to the base surface (1) are present in asymmetrical form at the output of the asymmetrizing network (9) at the second collection point for symmetrical voltages (11a) (Fig. 3 c, 4d).
19. Antenna according to claim 18,
    characterized in that
    a vertical antenna conductor (20) connected at one end to the ring structure (2) is formed along the symmetry line (8), and a connecting gate (Tu) for formation of an asymmetrical voltage ~Uu is formed at the end of the vertical antenna conductor (20) adjacent to the conductive base surface (1) (Fig. 9a, 9b).
20. Antenna according to claim 19,
    characterized in that
    a matching network (29) for configuration of matched coupling out of the asymmetrical voltage -Uu is provided in addition to the asymmetrizing network (9), which on the input side is connected to the antenna connection points (5) constructed as the first connecting gate (T1a) and second connecting gate (T1b), and to the low-loss matching circuit (17) (Fig. 9b).
21. Antenna according to claim 20,
    characterized in that
    the vertical antenna conductor (20) is connected to the two antennas at their intersection and symmetry point (12) (Fig. 10a, 10b).
22. Antenna for reception of circularly polarized satellite signals according to one of claims 10, 21 and 22,
    characterized in that
    when the length of the portion (16) is about one quarter of the operating wavelength, the capacitance of the impedance (7) is chosen such that the reactance is about 5 to 30 times greater than the impedance of a quarter-wave monopole antenna and thus is sufficiently large that the antenna gain of radiation incident at small elevation angles and the radiation incident from the zenith is sufficiently large to satisfy the requirements. (Fig. 6c, 7, 8, 10a, 10b)
23. Antenna according to claim 19 to 22,
    characterized in that
    an asymmetrical voltage ~Uu is supplied or drawn at the connecting gate (Tu) for the additional transmission or reception operation during omnidirectional radiation with vertical polarization (Fig. 10a, 10b).
24. Antenna according to claim 23,
    characterized in that,
    in the event of a difference in the frequencies of the symmetrical voltage Us and the asymmetrical voltage Uu, the decoupling between the collection point (11b) for asymmetrical voltages and the collection point (11a) for symmetrical voltages, which is limited due to residual asymmetry of the arrangement, is improved by frequency-selective measures in the matching network (29) and/or in the matching circuit (17).
25. Antenna according to claim 3 to 24,
    characterized in that
    in the event of discontinuities in the conductive base surface (1) or in the event of inclination thereof relative to the horizontal in a manner deviating from the symmetry of the arrangement that otherwise exists, appropriately different values are chosen for the impedances (7) in the individual branches in order to compensate for the resulting perturbation of the directional diagram.
26. Antenna according to claim 1,
    characterized in that
    the conductor parts having substantially horizontal extent (4b) for formation of a roof capacitor (31) have sheet-type configuration and are routed in a surface (30) which in one of its dimensions is oriented substantially perpendicular to the plane (0). (Fig. 14a)
27. Antenna according to claim 26,
    characterized in that
    the conductor parts having substantially horizontal extent (4b) for formation of the roof capacitor (31) are formed from wire-like or strip-like conductors (32). (Fig. 14b)
28. Antenna according to 26 and 27,
    characterized in that
    the surface (30) is formed as a plane parallel to the conductive base surface (1) and preferably as printed circuitry. (Fig. 15a, 15b, 16)
29. Antenna according to claim 28,
    characterized in that
    in order to configure the ring structure (2), the conductor parts having substantially horizontal extent (4b) and a plurality of impedances (7, 7') are formed in such a way that, relative to the plane (0) in which the conductor parts having substantially vertical extent (4a) are routed, an arrangement that is also symmetrical with respect to the impedance values of the impedances (7, 7') is obtained, and symmetry of the arrangement is also achieved with respect to a symmetry plane (33) oriented perpendicular both to the base surface (0) and with respect to the base plane (1) (Fig. 17a, 17b)
30. Antenna according to claim 29,
    characterized in that
    the two identical antennas are formed in such a way that the plane (0) of the one antenna forms the symmetry plane (33) of the other antenna and vice versa, and the overall arrangement is configured from congruent quadrants with respect to the vertical symmetry line (8) formed from the line of intersection of the plane (0) with the symmetry plane (33) of the antennas. (Fig. 17c, 17d)
31. Antenna according to claim 30,
    characterized in that
    to form the roof capacitors (31) of suitable size respectively loading the conductor parts having substantially vertical extent (4a) at their upper end, and to form the impedances (7) as coupling capacitors (34) for formation of the ring structures (2) of both antennas in the surface (30), there are provided sheet-type conductor structures (35) which respectively are galvanically insulated from one another and whose peripheries adjacent to one another are suitably configured by shaping and by the isolating gaps (36) disposed therebetween (Fig. 18a)
32. Antenna according to claim 30,
    characterized in that
    to form the roof capacitors (31) of suitable size respectively loading the conductor parts having substantially vertical extent (4a) at their upper end, there are provided, in the surface (30), sheet-type conductor structures (35) which respectively are galvanically insulated from one another, and there is provided a central structure (37) which surrounds the vertical symmetry line (8) and to which the roof capacitors (31) are capacitively coupled to form the impedances (7) as the coupling capacitors (34) for formation of the ring structures (2) of both antennas. (Fig. 18b)
33. Antenna according to claim 31 and 32,
    characterized in that
    the region in the immediate vicinity of the vertical symmetry line (8) of conductor parts is left unoccupied, and the vertical antenna conductor (20) is nevertheless coupled capacitively to parts of the ring structure (2), such as the central structure (37) or the roof capacitors (31), and the radiator length (43) and the radiator coupling capacitor (38) are chosen so as to adjust the capacitive coupling to a value that ensures that a suitable impedance will be present at the connecting gate (Tu). (Fig. 19, 20)
34. Antenna according to claim 21 or 30 for coordinated and simultaneous reception of circularly polarized satellite radio signals and of vertically polarized radio signals radiated by terrestrial radio sources in a high-frequency band of closely adjacent frequency,
    characterized in that
    the vertical antenna conductor (20) with the matching network (29) is configured for reception of the vertically polarized terrestrial radio signals in the asymmetrical voltage Uu, and the antenna with matching circuit (17), phase-rotation element (18) and summation circuit (19) is configured for reception of the circularly polarized satellite radio signals in the voltage for circular polarization Uz, but no active frequency-selective measures for mutual discrimination of the satellite radio signals from the terrestrial radio signals are employed, because the decoupling resulting from the symmetry is exploited (Fig. 10a, 10b, Fig. 19, Fig. 20).
35. Antenna according to claim 34 for combined bidirectional radio operation with vertically polarized terrestrial radio sources,
    characterized in that
    a sufficiently large value is chosen for the radiator length (43) of the vertical antenna conductor (20) for the radio service with the lowest frequency, and corresponding matching networks (29a, 29b, 29c, ...) with outputs (40a, 40b, 40c, ...) for connection of the corresponding radio devices are provided for the radio services, and the inputs of the matching networks (29a, 29b, 29c, ...) are respectively connected to the connecting gate Tu, and frequency-selective isolating circuits (39a, 39b, 39c, ...) are contained in such a way that the matching conditions at the connecting gate Tu are mutually influenced as little as possible in the radio-frequency channels of the various radio services. (Fig. 21 a, Fig. 22)
36. Antenna according to claim 35,
    characterized in that
    for frequency-selective shortening of the electrically effective radiator length (43) for higher radio channel frequencies, interruption points with suitable circuits of reactive elements (41) are inserted in the long stretch of the vertical antenna conductor (20). (Fig. 21 a)
37. Antenna according to claim 35 and 36,
    characterized in that
    to avoid the radiation-induced coupling between the connecting gate Tu of the vertical antenna conductor (20) and the connecting gates T1a, T1b, T2a, T2b of the ring structures (2), there are provided, in the vicinity of the foot points of the conductor parts having substantially vertical extent (4a), decoupling networks (42), which act respectively to block signals at the frequency of a bidirectional radio operation with vertically polarized radio sources, but are configured to pass the frequency of the circularly polarized satellite radio signal. (Fig. 21b)

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