EP2548262B1 - Broadband omnidirectional antenna - Google Patents

Description

The invention relates to a broadband omnidirectional antenna according to the preamble of patent claim 1.

Omnidirectional antennas are used, for example, as indoor antennas. They are multiband capable and preferentially emit with a vertical polarization orientation. You can do this include a ground or ground plate, which may be designed, for example, disk-shaped, on the transversely and in particular perpendicular to the base plate a monopole radiator rises. The entire assembly is usually by means of a protective housing, i. covered by an antenna cover (radome).

An omnidirectional and thereby vertically polarized antenna is for example from the EP 1 695 416 B1 known. The known monopole radiator rises vertically above a base plate or counterweight surface from which it is galvanically isolated. The vertically polarized monopole radiator comprises at least approximately a conical or frustoconical radiator section (which points away from the base plate or counterweight surface with its divergent extension) and / or a cylindrical or cup-shaped radiator section. Preferably, the counterweight surface is adjoined first by the cone-shaped or frustoconical radiator section facing away from the counterweight surface with its diverging extension, which radiator section then merges into a tubular radiator section. A preferred supply via a serial line coupling, which is formed in the central or symmetry axis of the monopole radiator.

Such an antenna type has proven particularly useful as an indoor antenna. It is characterized by its wide bandwidth and simultaneous operation in different frequency ranges, and this with a very low overall design.

In addition to such omnidirectional antennas explained above, fundamentally completely different types of antenna have become known. That's how it describes US Pat. No. 5,220,337 For example, a directional radiator, which is formed, for example in the form of a cavity radiator with a plurality of offset on its peripheral side walls in the circumferential direction lying slots, wherein the slots are fed separately via separate coaxial cables.

From the DE 10 2008 003 532 A1 is to take an antenna for satellite reception as known. This antenna comprises a broadband omnidirectional antenna with a monopole radiator that is vertically polarized and rises above a base or counterweight surface. The omnidirectional antenna is designed as a dual-polarized antenna, wherein the dual-polarized antenna in addition to the vertically polarized monopole radiator comprises a horizontally polarized radiator.

From the publication " Vu TA et al .: UWB Vivaldi Antenna for Impulse Radio Beamforming. In: Conference Report NORCHIP 2009, pp. 1-5 "is a broadband Vivaldi or vivaldi-like antenna device in principle known to be known .. The shown and described Vivaldi antennas are constructed with a microstrip structure.

A monopole-shaped antenna in a cylindrical design is from the US 5,754,143 A known. The monopole comprises a slot inserted in a cylindrical jacket, which is arranged running meandering. In this case, longer sections of the meander-shaped slot antenna are arranged parallel to one another and parallel to a vertical axis, wherein these mutually parallel aligned and circumferentially offset from each other slot sections are connected to each other via a top or a bottom, horizontally extending slot portion. The monopole is determined by the longer, extending in the vertical direction and aligned parallel slot sections. In this case, this monopole radiator is operated by feeding the meandering slot. The feeding of the slot takes place in this case by means of a coaxial cable, wherein the outer conductor of the coaxial cable is galvanically connected to one edge of the slot, whereas over the outer conductor axially projecting inner conductor is passed across the slot and is electrically connected to the opposite edge of the slot.

From the generic pre-publication EP 0 195 356 A2 is a circularly polarized emitter for the satellite mobile in the L-band as known to remove. It proposes a slotted tube antenna with a cylindrical antenna tube of certain length as a vertically polarized linear radiator and introduced into the cylinder jacket of the cylinder tube, a single vertically extending slot. This longitudinal slot in a predetermined length serves as a horizontally polarized dipole. By a corresponding dimensioning of the antenna tube and formed in this single vertical slot and by a corresponding arrangement of the antenna focus on the well-conducting reflection plane is a circularly polarized total emitter with an optimum for satellite mobile radiation characteristics with a Rundumdiagramm in the azimuth plane and a bundling in the Elevation plane formed, the maximum radiation of the lobe is at a collection angle of about 30 °. This is a very specific antenna designed for a specific application of satellite radio. Also in this prior art, the slot is excited by means of a coaxial cable, which in turn the Außenleter at one edge of the slot and the slot crossing inner conductor at the opposite Slot edge is in each case galvanically connected to the jacket of the antenna tube.

Finally, out of the US 4,763,130 an antenna arrangement with a cylinder jacket to take as known, in which circumferentially offset from one another and parallel to each other and to the axial central axis extending slots are formed in the radiator shell, which are fed by means of a running inside the radiator shell feeding device. It is a pure monopole radiator.

Object of the present invention is to provide an omnidirectional antenna, which is basically broadband, opens up a wider range of applications compared to the prior art and also claim little space.

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

It can be described as quite surprising that the antenna according to the invention - compared with conventional solutions - discloses further advantages, without the antenna as a whole, for example, would take up more space.

In contrast to the generic type single polarized omnidirectional antenna according to the invention now consists of a dual polarized round radiator and includes a vertically polarized monopole radiator and an additional horizontally polarized radiator device.

According to the invention, it is now provided that the feed device provided in the interior of the lamp shroud for the plurality of slots comprises separate feed devices, via which the respectively assigned slots are excited separately. For this purpose, the feed device provided in the interior of the vertically polarized pole-shaped radiator comprises slot-shaped antenna devices in the form of tapered slot antennas (TSA) arranged offset from one another in several circumferential directions. In other words, therefore, the separate feed devices consist of the mentioned slot-shaped antenna devices in the form of tapered slot antennas (TSA).

The feed structure can be formed differently. For example, a central feed point (on a printed circuit board) may be provided from which the feed lines for the slot radiators emanate. Likewise, a tubular or frusto-conical support (in adaptation to the shape of the monopole radiator) could be inserted in the interior of this radiator on which the corresponding feed lines are formed using a galvanic contact with the electrically conductive outer surface of the monopole radiator. Different principles are feasible.

In a particularly preferred embodiment, however, as a horizontal radiator device is a multiple Vivaldi antenna arrangement proposed as a feed structure for the slots in the jacket of the monopole radiator.

As is known, a Vivaldi antenna is a special case of a "longitudinal antenna", more particularly a special case of a "tapered slot antenna" (TSA), the edges or edges of the slot preferably being from a closed end to its open end expand in a funnel shape with a defined exponential formula. This funnel-shaped widened slot thus serves as a radiating element, wherein the feeding and excitation of the slot can take place via a feed microstrip line crossing the slot.

With a suitable choice of geometrical dimensions and clever dimensioning of the power supply, Vivaldi antennas can be realized in a very broadband manner.

In the context of the invention, Vivaldi antennas or other, in particular linearly taped slot antennas have an advantage insofar as they are structurally simple to implement, can be arranged within the rotationally symmetrical hollow body of the monopole radiator (thus not contribute to an increase in the height ) And especially the preferred exponential funnel shapes, so the various radiation directions of Vivaldi antennas can be aligned directly with the slots in the rotationally symmetric or rotation-like formation of the lateral surface of the monopole radiator. By this structure and by the between the Vivaldi antenna and the slot-shaped configuration in particular the cylindrical The lateral surface of the monopole radiator results in a particularly high broadband while avoiding tolerance problems.

The number of mentioned slots in the lateral surface of the at least approximately rotationally symmetrical monopole radiator can be chosen differently. The higher the number of slots, the more circular the horizontal radiation pattern becomes. Preferably, at least three or four slots extending in the circumferential direction of the lateral surface of the monopole radiator are provided.

The length and width of the slots can be optimized according to the frequency ranges to be used. Preferably, the slots open in the vertical beam direction of the monopole radiator open, but may also be formed closed in particular with correspondingly longer dimensioning. Also, the slot structure in the circumferential direction may be repeatedly formed so that it is U-shaped, that consists of a double slot, in which case the remaining between the double slot electrically conductive surface can be held by a dielectric support structure, for example, for filling in the Slots are inserted. It would also be possible to form the entire or large parts of the monopole radiator on a dielectric body on which the corresponding electrically conductive lateral surface is formed as a layer, so that corresponding U-shaped double slots can be formed by omitting electrically conductive layer sections problem-free.

The feeding of the vertically polarized radiator device can take place via the central axis, ie the axis of symmetry of the monopole radiator, for example by means of a serial (capacitive) coupling for the monopole-shaped vertically polarized radiator, as described in US Pat DE 103 59 605 B4 is described. In this case, the feed of the horizontally polarized radiator is preferably realized by means of a coaxial cable which passes once through a passage opening in the mass or counterweight surface and is arranged to extend with a predetermined cable length on the counterweight surface until the coaxial cable through a further passage opening in the Mantle surface of the monopole radiator, where it is, for example, electrically conductively connected to this lateral surface, is guided into the interior, up to an aforementioned star-shaped distribution point of a corresponding feed structure for exciting the slots.

The coaxial feeders for the horizontally polarized radiator device, which extend outside the generally rotationally symmetrical monopole radiator, preferably have a length which is chosen such that it is not the multiple of λ / 2 of an operating wavelength used by the vertically polarized radiator.

In the context of the invention, the feed for the vertically and horizontally polarized radiator but also vice versa, so that, for example, the supply of horizontally polarized radiator in the vertical Central or symmetry axis takes place and the supply for the vertically polarized monopole radiator outside this central or symmetry axis.

Figur 1 :

eine räumliche Darstellung eines ersten erfindungsgemäßen Ausführungsbeispieles einer omnidirektionalen Antenne;

Figur 2 :

eine räumliche flachere Darstellung in Abweichung zu Figur 1 nur bezüglich des monopolförmigen Strahlers mit im Strahlermantel eingebrachten Längs- oder Vertikalschlitzen;

Figur 3 :

eine schematische axiale Querschnittsdarstellung senkrecht zur Gegengewichtsfläche bezüglich des Ausführungsbeispiels nach Figur 1 oder 2;

Figur 4 :

eine auszugsweise schematische Darstellung einer seriellen (kapazitiven) Speisung des monopolförmigen Strahlers;

Figur 5 :

eine schematische Draufsicht auf eine erste erfindungsgemäße Speisestruktur unter Verwendung von mehreren Vivaldi-Antennen;

Figur 6 :

eine entsprechende Ansicht zu Figur 5, jedoch auf die Rückseite der in Figur 5 wiedergegebenen Platinen- oder Speisestruktur;

Figur 7 :

eine vertikale Längsschnittdarstellung vergleichbar zu Figur 3 jedoch bezüglich eines abgewandelten monopolförmigen Strahlers;

Figur 8 :

eine perspektivische Darstellung eines nicht zur Erfindung gehörenden Beispiels einer omnidirektionalen Antenne ohne Wiedergabe der Gegengewichtsfläche;

Figur 9 :

eine ausschnittsweise Darstellung auf einen Vertikalschlitz in der Mantelfläche des monopolförmigen Strahlers 1 im Falle einer nicht zur Erfindung gehörenden koaxialen Speisestruktur; und

Figur 10:

ein zu Figur 1 abgewandeltes Ausführungsbeispiel unter Verwendung von Doppel-Schlitzen.

The invention will be explained in more detail with reference to drawings. In detail:

FIG. 1:

a spatial representation of a first embodiment of an omnidirectional antenna according to the invention;

FIG. 2:

a spatial flatter representation in deviation to FIG. 1 only with regard to the monopole radiator with longitudinal or vertical slots introduced in the radiator shell;

FIG. 3:

a schematic axial cross-sectional view perpendicular to the counterweight surface with respect to the embodiment according to FIG. 1 or 2 ;

FIG. 4:

a partial schematic representation of a serial (capacitive) supply of the monopole radiator;

FIG. 5:

a schematic plan view of a first inventive feed structure using multiple Vivaldi antennas;

FIG. 6:

a corresponding view too FIG. 5 but on the back of the in FIG. 5 reproduced board or feed structure;

FIG. 7:

a vertical longitudinal section comparable to FIG. 3 however, with respect to a modified monopole radiator;

FIG. 8:

a perspective view of a non-inventive example of an omnidirectional antenna without playback of the counterweight surface;

FIG. 9:

a detail of a vertical slot in the lateral surface of the monopole radiator 1 in the case of a not belonging to the invention coaxial feed structure; and

FIG. 10:

one too FIG. 1 modified embodiment using double slots.

Based on FIGS. 1 to 4 First, a first embodiment of the invention is explained in more detail.

According to this variant, the dual polarized omnidirectional antenna comprises a substantially vertically polarized antenna device 1 (i.e., a substantially vertically polarized radiator 1) and a substantially horizontally polarized antenna device 3 (i.e., substantially horizontally polarized radiator device 3).

In this case, the entire antenna arrangement is constructed on a base, base or ground plate 5 or surface 5, which is also referred to below as a counterweight surface 5 or reflector 5. Im shown Embodiment, this counterweight surface 5 is designed circular or disc-shaped. But completely different shapes are possible. Thus, the counterweight surface 5, for example, square, rectangular, oval, etc. may be formed, in general so also n-polygonal, etc. Other embodiments of the counterweight surface, for example as a grid, are conceivable.

The vertically polarized antenna device 1 consists essentially of the aforementioned monopole-like radiator device 1, which is designed in the form of a hollow cylinder in the embodiment shown. In other words, the vertically polarized monopole radiator 1 is at least approximately rotational body 11, i. in particular as an inner hollow rotary body 11 with a rotary or radiator sheath 11a is formed which is rotationally symmetrical to a central or symmetry axis 9. For this purpose, the rotary body 11 has a predetermined height H, which is measured from the counterweight surface 5 to the upper edge 13 of the cylindrical monopole radiator 1.

The monopole steel 1, in the embodiment shown in the form of a cylindrical radiator device 1a, is galvanically separated from the mass or counterweight surface 5, as in particular in the very oblique perspective view according to FIG. 2 as well as in the axial vertical sectional view of Figure 3 can be seen.

From this it can also be seen that the cylindrical radiator device 1a next to the here cylindrical radiator shell 11a the cup-shaped, adjacent to the mass or counterweight surface 5 extending bottom 11b includes.

The structure and the feed of these thus formed vertically polarized monopole or monopole radiating device 1 can be made as it is basically from the DE 103 59 605 B4 is known, the disclosure of which is fully incorporated by reference.

From this prior publication it can be seen that, for example, as in FIG. 4 shown, in the middle of the base plate 5, a recess 15 is incorporated and that here a coaxial connector 17 is fixed, the outer conductor 17a is electrically connected, for example, with the ground or counterweight surface 5, and its inner conductor 17b by suitable measures (insulator disk) from the outer conductor 17a is disconnected. The inner conductor 17b is passed through the recess 15 within the outer conductor 17a and electrically-galvanically connected to a above the base plate 5 extending over a certain height inner conductor coupling element 19. This coupling element 19 preferably extends perpendicular to the plane of the counterweight surface 5. Thereupon, an insulating sleeve 21 is placed, with a widened flange below 21a, on which then the formed with a cylindrical coupling portion 11c vertically polarized radiator device 1, 1a with its cylindrical radiator shell 11a placed is, wherein the cylindrical radiator shell 11a electrically via the bottom 11b with the cylindrical coupling portion 11c, that is galvanically connected.

Otherwise, how simplified in FIG. 3 is shown in cross-section, the radiator 1 are fed with its electrically conductive radiator shell 11a via an inner conductor 17b, which passes through an electrically connected to the counterweight surface 5 outer conductor 17a thereof, whereby a coaxial connector 17 is formed in the region of the recess of the counterweight surface 5 ( as in FIG. 3 to see). Usually, an insulator is also provided between the inner and outer conductors and between the counterweight surface 5 and the bottom 11b, by means of which the emitter 1 is kept separate from the counterweight surface 5 and the inner conductor 17b is separated from the outer conductor 17a.

From the further illustrations, it can be seen that in the exemplary embodiment shown at a small distance D below the upper edge 13 of the radiator device 1, 1 a a substrate or a dielectic 23 is arranged, which serves as the base section of several Vivaldi antenna devices 25. These multiple Vivaldi antenna devices 25 form a feed structure 111 for feeding the slits explained below into the radiator shell 11a of the monopole radiator 1, 1a.

In that regard, with regard to the feed structure of one of the 11 following partial also of feed devices one of 11 is spoken, which comprises a plurality of separate feeders 111a, about which the respectively associated below-mentioned slots 43, 43 'are separately excited.

In principle, Vivaldi antenna devices are "tapered slot antennas" (TSAs) - ie expanded slot antennas. These are therefore broadband antennas, which are also used as sole radiation elements, for example in the millimeter-wave range. Often they are realized on a double-sided metallized substrate 23.

In the embodiment shown, the dielectric 23 is disc-shaped and has a diameter which is equal to or slightly smaller than the inner diameter of the cylindrical electrically conductive jacket 11a.

Corresponding FIG. 5 are provided on this disc-shaped substrate 23 in the circumferential direction at equal intervals, four Vivaldi antennas 25, which are therefore in other words in a 90 ° distance circumferentially offset from each other formed.

The Vivaldi or Vivaldi-like antenna devices 25, ie in general the "tapered slot" antennas 25, consist of a carrier material or substrate 23 (dielectric 23), in which, for example, a conductive layer 27 is formed on the underside 23a facing the counterweight surface 5 , the offset by 90 ° in the circumferential direction to each other radial slotted or groove-shaped recesses 29 (s. FIG. 5 ). Each of the slot-shaped recesses 29 begins with a circular recess 33 typically adjacent to the vicinity of the center 31 of the substrate 23, wherein of the four circular, also in 90 ° in Circumferentially offset recesses 33 in each case the outwardly funnel-shaped widening slot-shaped structure 29 emanates, in the region of which the substrate 23 is freed from a conductive layer. By means of this circular clearance 33, the slot line 29 'formed by the slot-shaped recess 29 is completed in a broadband manner, this circular clearance 33 preferably being long by a quarter wavelength. In the exemplary embodiment shown, the slot-shaped recesses 29, which widen outwards in the shape of a funnel, extend in the radial direction, ie they are preferably symmetrical with respect to a radial vector passing through the center 31.

The edges 29 "of the slot-shaped recess 29 delimiting the slot lines 29 'can be designed differently for adapting the broadband of the antenna." Preferably, these slot lines 29' have a funnel-shaped widening towards the outside, the curve of the edges 29 delimiting the slot lines 29 ". can follow an exponential function.

The feeding of each slot line 29 'via a respective slot feed line 35, the sitting of a branching or crossing point 37 (star branch 37) in the center 31 of the substrate 23, which is penetrated by the central axis 9 and symmetry. Assuming this, each of the slot feed lines 35 initially extends with a radial line section 35a, to which a second line section 35b extending at right angles thereto adjoins in the exemplary embodiment shown (which runs parallel to the lines 31 extending from the center 31) Radial vectors runs), in order then in a third, again at right angles angled line section 35c, which cuts the respective slot line 29 'transversely and preferably perpendicularly. Other, for example, arcuate courses of the feeders 35 are also possible. The decisive factor is that they emanate from a star point and cross the slot line 29.

In order to improve the broadband nature of these Vivaldi antennas, it is provided that the strip line-shaped slot lines 35 on the substrate are terminated with a corresponding surface element 35d, which may be triangular or circular-sector-shaped or similar.

The respective multiple bends of the feed slot lines 35 take place in the same direction in the circumferential direction, so that a next slot line section 35b and so on adjoin each radial line section 35a in the circumferential direction continuously in the same direction.

The mentioned slot supply lines 35 are formed on the upper side 23b of the substrate 23, that is opposite to the slot lines 29 'of the Vivaldi antennas 25 (s. FIG. 6 wherein the slot lines 29 'formed on the opposite side of the substrate 25 are shown by dashed lines).

A coaxial feed line leading to the branching point 37 for this horizontal antenna arrangement is connected such that the outer conductor of a coaxial cable 41 is electrically connected to the conductive layer 27 on the underside 23b of the substrate 23, whereas the inner conductor of such a coaxial cable connection is passed through an opening in the substrate 23 upwards and galvanically connected to the central star branch point 37.

As can also be seen from the drawings, the individual outwardly funnel-shaped widened slot lines 29 'are arranged so that their outwardly facing opening portions 29a each adjacent to in the lateral surface 11a of the cylindrical radiator device 1, 1a extending slots 43 end, so that via the respective Vivaldi antenna or generally the "tapered slot" antenna 25 of the corresponding vertical slot 43 is excited.

The circuit board or supply structure is therefore also characterized in that the slot lines 29 'resulting from the free spaces 33 outgoing slot lines 29' on the board or the substrate 23 for all slot or Vivaldi antennas 25 a common contiguous metallized surface 27th although the metallized areas for the individual Vivaldi antennas could be separated, which is not so advantageous. The omnidirectional characteristic can be further improved by increasing the number of corresponding Vivaldi antennas which are offset in the circumferential direction. In other words, also 2, 3 or 5, 6, 7, etc. Vivaldi antennas could be arranged offset in the circumferential direction, in which case on the opposite side a correspondingly larger number of feeders 35 are provided should be, whose individual supply line sections 35a, 35b, 35c would have to be angularly adjusted so that the last, the actual feed causing feeder line section 35c respectively the corresponding slot-shaped recess 29 intersects, namely preferably perpendicular to the radial extent.

In summary, it can therefore be mentioned that the feed structure 111 is fed with a provided on the top of the board 23 feed network in the middle by a coaxial cable 41 from below (via an inner conductor of the coaxial cable), wherein on the idle microstrip lines with broadband stubs as Conclusion each a Vivaldi antenna 25 (as a special case of a TSA) is fed, which are located on the underside of the board. The electric field propagates in each individual Vivaldi antenna from the center to the edge of the board, whereby the electric field vector in the slot is parallel to the surface of the board. In other words, the electric field vector is already horizontally polarized relative to the overall antenna. By this electric field, in turn, the individual slots 43 are excited to radiate.

Usually, the omnidirectional antenna is constructed so that the monopole radiator 1 faces in the vertical direction, that is, the counterweight surface is aligned horizontally. Accordingly, the feed structure 111 with the board or the substrate 23 is horizontally aligned (namely, parallel to the counterweight surface and thus perpendicular to the monopole radiator), so that from the inside to the outside preferably funnel-shaped widening slot radiator (Vivaldi radiator) are aligned in the plane parallel to the counterweight 5 horizontal plane and thus act this radiator as a horizontal radiator. With a correspondingly different orientation of the antenna, the corresponding vertical and horizontal directions would point in different directions, depending on the antenna orientation.

In other words, therefore, for the slotted and / or traveling wave antennas in question, a feed structure is preferably proposed on a printed circuit board, via which a coupling to the slits can take place from a central point, in particular capacitively. By using the Vivaldi antennas, a double radiation-coupled feed takes place at the slots 43, namely via the feed slot line 35 with respect to the slot line 29 'and then with respect to the feed to the provided in the lateral surface 11a, away from the counterweight surface 5 slots 43rd

As already mentioned, the feed line 41 for feeding the Vivaldi antenna elements 25 in the interior 11d of the rotationally symmetric and internally hollow body of revolution 11 or Strahlermantel 11a extend, for example, the mentioned coaxial feed cable 41 in the interior 11d via a bore 45 through the bottom 11b or Mantle surface 11a of the vertically polarized antenna device 1 and is passed through a further bore 47 in the counterweight surface 5 on the underside of the counterweight surface 5. At the bottom of the counterweight surface 5, the coaxial cable 41 may be connected to a further coaxial connector 117. This section 41a of the feed cable 41 outside of the radiator 1 and above the counterweight surface 5 is not intended to be an integer multiple of half of an operating wavelength used by the vertically polarized antenna.

For the sake of completeness, it is noted that the supply of the vertically polarized monopole radiator 1 via the mentioned serial (capacitive) power supply in the center of the antenna array (or via the central supply accordingly FIG. 3 via a connector provided there) and the feeding of the horizontally polarized radiator device 3 via offset coaxial cable 41 or vice versa can be made such that the Vivaldi antenna devices 25 are fed centrally via a running in the central axis 9 coaxial cable, whereas the vertically polarized monopole-shaped Radiator device 1 is fed via a radially offset eccentric coaxial cable.

Based on FIG. 7 is shown schematically in vertical section that the monopole-shaped vertically polarized antenna device 1 need not necessarily consist of a cylindrical steel body 1a, but alternatively may consist of a running away from the counterweight surface 5 cone or frusto-conical radiation body 1b or preferably from a radiation body, the offset Starting from the ground surface 5, a conically widening first antenna section 1b and an adjoining cylindrical antenna section 1a comprises, as is basically the case from the already mentioned DE 103 59 605 B4 is known, to whose disclosure content in so far in Full reference is made. This also forms a rotational body 11 or at least approximately a rotational body 11 as a particularly efficient, vertically polarized monopole-shaped radiator. In this case, the slots 43 running away from the counterweight surface 5 in the radiator shell 11a could be formed completely or partially at the level of the conically widening radiator 1b or radiator section 1b, although this somewhat impairs the emission behavior.

In the following, modifications are discussed in more detail.

Based on FIG. 8 FIG. 2 shows a non-inventive example in which the feed of the vertical slots 43 in the cylindrical or envelope-shaped radiator 1a of the vertically polarized monopole radiator 1 is not via tapered slot antenna devices (TSA) but, for example, via a microstrip antenna. Radiation coupling takes place.

In this embodiment, a substrate or a dielectric 23 is likewise provided in the interior of the rotationally symmetrical or rotation-like radiator 1 designed as a hollow body which, starting from a central point 37, comprises a slot feed line 35 which likewise comprises a first radial line section 35a (the one of FIG mentioned star point 37 emanates), and then immediately adjacent to the hollow body-like cylindrical or frusto-conical shell 11a of the radiator device 1 merges into a part-circular slot line section 35b immediately adjacent to the inner wall 11 "of the radiator jacket 11a and intersecting the vertical slots 43 introduced there (preferably parallel to the counterweight face 5). As a result, the slots 43 can be excited correspondingly in principle, as is the case with slot antennas.

In this case, the additional feed structure 111 provided in the interior 11 'of the vertically polarized antenna device 1, 1a for the horizontally polarized antenna device can be arranged deeper below the upper circumferential edge 13, in particular also because, in the embodiment according to FIG FIGS. 8 and 9 is shown that here the total height H of the cylindrical vertically polarized antenna device 1 higher than in the embodiment according to FIG FIG. 1 can be and therefore also vertical slots 43 are used, which are not open on one side upwards, but are closed in both directions, that are limited by a corresponding skirt portion of the vertically polarized antenna device 1. Therefore, the slit length of the slits 43 should differ from the embodiment of FIG FIGS. 1 to 7 not by λ / 4, but by λ / 2 amount.

Deviating from FIG. 8 is in an enlarged detail illustration according to also not belonging to the invention FIG. 9 shown that a supply of the vertical slots 43 (regardless of whether they are closed or as the embodiments of the FIGS. 1 to 4 open at the top) not only via microstrip lines, but also via coaxial cable 49 or any other lines that consist of at least two conductors (two-wire line, microstrip, slotline etc.), wherein the outer conductor 49a of the coaxial cable 49 preferably terminates in front of the respective vertical slots and is galvanically connected to the inner jacket 11 'of the cylindrical radiator 1, whereas the inner conductor 49b crosses the slot 43 and projects beyond it in the transverse direction.

On the basis of the previous embodiments, strip-shaped, i. in particular rectangular slots 43, 43 'have been shown. The slots may also have a different shape. It is possible, for example, that the slots are designed trapezoidal or apart from a middle section upwards and downwards trapezoidal or run together, etc. Various modifications can be realized here. In general, however, the central longitudinal line of the slots 43, 43 'in the radiator shell 11a of the rotating body 11 of the monopole radiator 1, 1a be introduced so that these mean longitudinal line in the slots 43 in a vertical plane perpendicular to the counterweight 5, in which is also the central or symmetry axis 9 of the entire omnidirectional antenna.

Finally, based on FIG. 10 shown in sections that the slots 43 in the rotationally symmetrical shell 11a of the monopole radiator 1 can also be formed as U-shaped double slots 43 ', which are open at the top.

The corresponding wavelengths are each related to the associated operating frequencies in which the omnidirectional antenna is to be used.

In this case, it is advisable that the material portions 11x (which are metallized and / or electrically conductive) remaining between the double slots are held in the slots 43 by dielectric inserts or the entire structure is constructed on a dielectric, in which accordingly conductive surfaces are applied, with the omission of electrically conductive layers at the locations where the slots or double slots or U-shaped slots 43, 43 'are formed.

Such an omnidirectional antenna can be used for different operating frequencies or operating bands. In particular, different frequency ranges for the horizontal and for the vertically polarized antenna are possible within the available total volume of the antenna, if this brings an advantage.

Depending on the diameter of the monopole, the number of slots is selected. The distance between adjacent slots on the surface of the monopole radiator should not be too large, in particular not greater than λ (where λ is an operating wavelength used by the horizontally polarized antenna unit) to ensure sufficient roundness of the radiation characteristic of the horizontally polarized antenna.

All explained embodiments is common that the slots 43, 43 'through the feed structure 111, for example in the form of coaxial cables, in the form of a Radiation coupling using microstrip lines or in the form of slot antennas (in particular Vivaldi antennas) are each separately excited and fed. As a result, a linear polarization in the horizontal plane is achieved with a corresponding orientation, namely, when the board structure and the counterweight surface are aligned in the horizontal direction and the monopole radiator points in the vertical direction.

Claims (23)

1. Broadband omnidirectional antenna having the following features:

   - comprising a monopole radiator (1; 1 a, 1 b),

   - the monopole radiator (1; 1 a, 1 b) is vertically polarised,

   - the vertically polarised radiator (1; 1 a, 1 b) rises above an earth plate or counterweight surface (5), the monopole radiator (1; 1 a; 1 b) being galvanically isolated from the earth plate or counterweight surface (5),

   - the monopole radiator (1; 1 a, 1 b) comprises a radiator casing (11 a) which extends away from the earth plate or counterweight surface (5),

   - the omnidirectional antenna is in the form of a dual-polarised antenna,

   - in addition to the vertically polarised monopole radiator (1; 1a, 1b), the dual-polarised antenna comprises a horizontally polarised radiator (3),

   - the horizontally polarised radiator (3) comprises slots (43, 43'), which are provided in the radiator casing (11a) of the vertically polarised monopole radiator (1; 1 a, 1 b) so as to be positioned mutually offset in the circumferential direction and oriented so as to be perpendicular to the earth plate or counterweight surface (5),

   - the supply means (111) provided in the interior of the radiator casing (11a) comprises separate supply means (111 a), via which the respectively associated slots (43, 43') are excited separately, for the plurality of slots (43, 43'),

   characterised by the following features:

   - the supply means (111) provided in the interior of the vertically polarised monopole radiator (1; 1 a, 1 b) comprises a plurality of slot antenna means in the form of tapered-slot antennae (TSA) which are arranged mutually offset in the circumferential direction.
2. Antenna according to claim 1, characterised in that at least three or at least four slots (43, 43') are arranged in the circumferential direction of the monopole radiator (1; 1 a, 1 b) so as to be positioned mutually offset at equal distances in the circumferential direction.
3. Antenna according to either claim 1 or claim 2, characterised in that the slots (43) in the radiator casing (11) of the vertically polarised monopole radiator (1; 1 a, 1 b) are arranged so as to extend in such a way that they are each parallel to a plane in which an axis of symmetry or central axis (9), which passes through the antenna and is perpendicular to the counterweight surface (5), is also positioned.
4. Antenna according to any one of claims 1 to 3, characterised in that the slots (43, 43') are formed so as to extend away from the earth plate or counterweight surface (5), offset from the earth plate or counterweight surface (5), in the radiator casing (11), and end open on the side remote from the earth plate or counterweight surface (5) at the upper rim (13) of the monopole radiator (1; 1 a, 1 b).
5. Antenna according to claim 4, characterised in that the slots (43, 43') have a length of approximately λ/4.
6. Antenna according to any one of claims 1 to 3, characterised in that the slots (43, 43') are formed so as to extend away from the earth plate or counterweight surface (5), offset from the earth plate or counterweight surface (5), in the radiator casing (11 a), and are closed on the side remote from the earth plate or counterweight surface (5), adjacent to the upper rim (13) of the monopole radiator (1; 1 a, 1 b).
7. Antenna according to claim 6, characterised in that the slots (43, 43') have a length of approximately λ/2.
8. Antenna according to any one of claims 1 to 7, characterised in that the slots (43, 43') in the radiator casing (11) are configured so as to be strip-shaped or preferably so as to extend in a trapezium shape proceeding from the centre thereof towards or away from the earth plate or counterweight surface (5).
9. Antenna according to any one of claims 1 to 8, characterised in that the supply means (111) in the form of tapered-slot antennae (TSA) consists of or comprises a plurality of Vivaldi or Vivaldi-like antenna means (25) which are arranged mutually offset in the circumferential direction about a central axis of symmetry (9) of the antenna.
10. Antenna according to claim 9, characterised in that the Vivaldi or Vivaldi-like antenna means comprise a substrate (23), on one side (23a) of which a metal-coated or electrically conductive layer (27) is formed, in the region of which slot-shaped recesses (29), which extend from the inside to the outside, positioned mutually offset in the circumferential direction, are provided so as to form a respective slot line (29'), and preferably extend in a funnel shape from the inside to the outside.
11. Antenna according to claim 10, characterised in that a plurality of supply lines (35) for separately supplying a respective slot line (29') are provided on the substrate (23) on the opposite side (23b).
12. Antenna according to either claim 10 or claim 11, characterised in that supply lines (35), which are formed proceeding on the substrate (23) from a centre (31) so as to be mutually offset in the circumferential direction, extend to the slot lines (29'), and for this purpose each comprise, proceeding from the centre (31), a first radially or approximately radially extending line portion (35a), a second line portion (35b) following on at an angle, and preferably a third line portion (35c), again extending at an angle thereto, which bridges the slot line (29') which is formed on the opposite side (23a) of the substrate (23).
13. Antenna according to any one of claims 10 to 12, characterised in that the slot lines (29') proceed, adjacent to the centre (31) of the substrate (23), from a preferably circular free space (33).
14. Antenna according to any one of claims 9 to 13, characterised in that the plurality of Vivaldi or Vivaldi-like antennae (25) are arranged in a plane and/or in a plane which is parallel to the counterweight surface (5), in particular in a horizontal plane.
15. Antenna according to any one of claims 12 to 14, characterised in that the supply lines (35) end in planar elements (35d) which are associated respectively therewith and are preferably formed in the shape of a triangle or a circle sector.
16. Antenna according to any one of claims 10 to 15, characterised in that the open region of the slot line (29') of each Vivaldi or Vivaldi-like antenna (25) ends adjacent to an associated slot (43, 43') in the radiator casing (11) of the monopole radiator (1; 1 a, 1 b).
17. Antenna according to any one of claims 1 to 8, characterised in that the supply means (111) consists of a radiation coupling arrangement, in particular in the form of a microstrip supply structure, in which corresponding supply lines (35) are arranged, preferably proceeding from an intersection point (37), in such a way that they go past, in the direct vicinity of an associated slot (43, 43') in the radiator casing (11 a) of the monopole radiator (1, 1 a), so as to cross the slot (43, 43').
18. Antenna according to any one of claims 1 to 17, characterised in that the vertically polarised radiator (1; 1 a, 1 b) is supplied centrally via a recess (15) in the earth plate or counterweight surface (5).
19. Antenna according to claim 18, characterised in that the monopole radiator (1; 1 a, 1 b) is supplied centrally in a series and/or capacitive manner.
20. Antenna according to claim 19, characterised in that the earth plate or counterweight surface (5) comprises a recess (15) through which an internal conductor (17b) of a coaxial supply line is guided and galvanically connected to an internal conductor coupling element (19) which extends over a particular height above the earth plate or counterweight surface (5), the internal conductor coupling element (19) being enclosed by a cylindrical coupling portion (11 c), which is galvanically connected to the monopole radiator (1; 1 a, 1 b), so as to provide a series and/or capacitive supply to the monopole radiator (1; 1 a, 1 b).
21. Antenna according to any one of claims 1 to 20, characterised in that the horizontally polarised radiator (1; 1 a, 1 b) is supplied via a coaxial line (41, 41 a), which extends on the side of the earth plate or counterweight surface (5) facing towards the vertically and horizontally polarised radiators (1, 3), specifically between a through-opening (47) in the earth plate or counterweight surface (5) and a through-opening (45) in the radiator casing (11 a), the length of the coaxial cable (41 a) which extends in this region being selected in such a way that it is not an integer multiple of λ/2 for an operating frequency of the vertically polarised radiator.
22. Antenna according to any one of claims 1 to 17, characterised in that the horizontally polarised radiator means (3) is supplied centrally via a recess (15) in the earth plate or counterweight surface (1; 1 a, 1 b).
23. Antenna according to any one of claims 1 to 22, characterised in that the monopole radiator (1; 1 a, 1 b) comprises an at least approximately conical or frustum-shaped radiator portion (11), the divergent extension of which points away from the earth plate or counterweight surface (5), and/or a cylindrical or cup-shaped radiator portion (11).

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