EP3440738A1

EP3440738A1 - Antenna device

Info

Publication number: EP3440738A1
Application number: EP17716202.1A
Authority: EP
Inventors: Mario Schühler; Lars Weisgerber; Mengistu TESSEMA; Rainer Wansch; Michael Schlicht
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date: 2016-04-07
Filing date: 2017-04-06
Publication date: 2019-02-13
Anticipated expiration: 2037-04-06
Also published as: JP2019514285A; DE102016207434A1; WO2017174736A1; US20190044238A1; CN109219906A; CN109219906B; US11223131B2; DE102016207434B4; JP6795614B2; EP3440738B1

Abstract

The invention relates to an antenna device (1) having an emitter element (4) for emitting and/or receiving electromagnetic signals. The emitter element (4) has at least one coupling point (5) which is connected to one side (40) of the emitter element (4) joined and is configured for capacitive coupling in and/or out of electromagnetic signals.

Description

antenna device

Description The invention relates to an antenna device. The antenna device is used in particular for transmitting and / or receiving electromagnetic signals.

The constant reduction or miniaturization of electronic and electromechanical systems ultimately also requires the corresponding reduction of the required components without losing any of their performance. On the contrary, the increase in the performance of these modules is sought.

In addition, the demand for wirelessly communicating components, and hence the requirement for downsizing the antennas as the core of these assemblies, is also increasing. This is one of the fundamental problems of miniaturization of systems, because the development and ultimately the dimensions of the required antenna elements are subject to certain physical limits.

Depending on their shape, size and power supply, antennas have different alignment characteristics with different properties. There are a variety of antenna shapes to meet the amount of requirements desired for the application. Here, the supply or coupling of the signal source to the radiator element plays a crucial role, because in addition to the shape and size of the properties of the radiated wave and the Fußpunktimpedanz the antenna are determined significantly. Such properties can z. B. shape of the lobe, but also especially the polarization (linear, circular, elliptical), the polarization purity (polarization decoupling) and the omnidirectionality of the radiated free-space wave. The impedance bandwidth and the frequency dependence of the directional characteristic are also important factors of an antenna for broadband wireless communication. In order, for example, to generate lobe shapes (so-called beamforming) with group antennas as uniformly as possible and extremely similar lobes in different spatial directions, a high polarization purity and omnidirectionality of the directional characteristic of the individual element is required. For many applications, eg. For example, in UHF RFID (Ultra High Frequency Radio Frequency Identification) reading ports, circularly polarized antennas are typically used to to capture the mostly linearly polarized passive transponders even with very different orientations in the room. For this purpose, multi-beam antennas are increasingly used in order to cover a larger angular range or space by means of a plurality of beam characteristics (beams). This makes it possible to securely identify a plurality of transponders frequently arranged in a cluster. In addition, such a multi-lobe antenna makes it possible to determine the position of the transponders in the room (localization). For this purpose, very uniform and symmetrical beams are required, the generation of which is possible only by the aforementioned radiation properties of the individual element of the array antennas.

For many applications, the antennas must be inexpensive. To z. For example, to inexpensively produce a circularly polarized directional characteristic, a radiating element (usually in the form of a patch antenna) is often coupled to two feed points offset by 90 ° (see, eg, "Patch Antenna (Circular), 860 - 930 MHz" of Poynting Antennas (Pty.) Ltd.). This happens, for example, galvanically by wire lines below the patch. Here is usually a feed network (usually in microstrip line technology) is needed, which allows the phase shift of the supplied power of 90 °. However, the directional characteristic here has a poor polarization purity or cross-polarization discrimination (XPD), which results in asymmetric lobes during beamforming. Likewise, this structure requires that the patch diameter must be on the order of half a wavelength and a large ground plane or a reflector are required to keep the reversion (cross-polarization) low. The bandwidth of such a structure is very low. In order to develop antennas with small dimensions and thereby produce a directional characteristic with high polarization purity and Omnidirektionalität, ceramic antennas can be used. These are very expensive and generally very narrowband. A more favorable method is to excite the radiating element at four feed points offset by 90 ° in each case [1]. It is advantageous to use a radiator as a sheet metal element with bent on the four sides by 90 ° connection segments and to solder directly to the board; also the supply by wire elements is conceivable [2]. This requires a compact and decoupled feed network [1], which provides the four offset by 90 ° phases. Due to the four-point feed, the diameter of the radiator element can be reduced to well below half a wavelength and at the same time a high bandwidth can be achieved. The bandwidth is slightly larger than the two-point powered solution. However, lossy required to adjust the radiator and increase its bandwidth. Furthermore, a very large ground area compared to the dimensions of the radiator element is required to keep the back radiation (cross-polarization) low. Likewise, the radiator element has a significantly greater electrical height compared to the idea described.

Another way to connect the patch element is to dis- connect the cable-guided wave via slots in the ground plane (see [3]). In this case, a microstrip line (usually orthogonal) crosses the slot in the ground line. In order to enable a circular polarization of the wave, the method of two- or four-point feeding can also be used here. This does not necessarily require a patch, but in both cases a reflector to reduce the reverberation and thus increase the profit. The disadvantage is that the dimensions of the opposing feed points (slots) and the diameter of the patch amount to about half the wavelength of the signals that are emitted or received.

In the methods described, the dimensions of the radiator element or the distances of the feed points are of the order of half a wavelength. If these dimensions were to be reduced, the base point impedances of the radiator element would increase significantly in terms of magnitude: the smaller the radiator element, the greater the magnitude of the base-point impedance. This complicates impedance matching to 50 ohms or even 00 ohms and is generally associated with high power losses through the matching elements and a reduction in bandwidth. This makes a low-loss adaptation of radiator elements or at feed point distances significantly smaller than half the wavelength (eg one quarter of the wavelength) almost impossible.

The object of the invention is to propose an antenna device which permits miniaturization without significant loss of radiation properties.

The invention achieves the object by an antenna device which has a radiator element for emitting and / or receiving electromagnetic signals. In this case, the radiating element has at least one coupling point. The coupling point is connected to one side of the radiator element. In addition, the coupling point is designed for the capacitive input and / or decoupling of electromagnetic signals. In some of the following embodiments, the coupling point is directly on one side of the radiating element available. The page refers depending on the design of the outer surface or outer border of the radiator element. In alternative embodiments, the radiation element on the at least one side is expanded, as it were, by an element - a wing element - which carries the coupling point. Depending on the configuration is thus directly or indirectly - in particular via a wing element - the at least one coupling point on one side of the radiator element. In this case, the coupling point is an area via which electromagnetic signals are coupled in for emitting into the radiator element or are coupled out of the radiator element via the signals received by the radiating element.

The antenna device is a single antenna or is part of a plurality of individual radiators or a group antenna.

The radiating element is the part of the antenna device which serves for the actual radiation or the actual reception of the electromagnetic signals.

If the radiating element has the coupling point directly at its side, then in one embodiment a web element for the capacitive coupling is present at the height of the side of the radiator element.

In one embodiment, the antenna device has a conductor structure for conducting electromagnetic signals. In this case, the conductor structure and the radiating element are capacitively coupled to one another via the coupling parts. The conductor structure is z. B. of electrical lines or printed conductors formed on a semiconductor substrate. The connection between the radiating element and the conductor structure for transmitting the electromagnetic signals takes place capacitively and in particular free from a galvanic coupling.

In one embodiment, the radiation element has at least one wing element. In this case, the radiator element and the wing element are galvanically coupled with each other. Furthermore, the wing element is arranged on the side of the radiator element. In addition, the radiator element and the Flügeleiement form an angle with each other and the wing member has the coupling point. In this embodiment, therefore, the coupling Stelie is indirectly via the wing member on the side of the radiator element. Depending on the design, the radiator element and the wing element or possibly wing elements are in one piece executed or the wing element or the wing elements are connected to the radiator element.

The flight element is made in one embodiment of an electrically conductive material, in particular a metal.

In one embodiment, the antenna device has a carrier element. In one embodiment, the conductor structure is at least partially applied to the carrier element. If, in one embodiment, the conductor structure consists at least partially of conductor tracks, then in a complementary embodiment, these conductor tracks have been applied or produced on the carrier element. In one embodiment, the carrier element, for example, a substrate on which the conductor structure - z. B. with thin film or thick film process - has been applied. In a further embodiment, the wing element is angled in the direction of the carrier element of the radiating element. The wing element thus extends from the side of the radiator element in the direction of the carrier element. Furthermore, the coupling point is located at a free end of the wing element. The free end is the end of the wing element, which is remote from the side of the radiator element and therefore also from the radiator element. The free end is therefore an end that is not connected to the radiator element.

In one embodiment, the radiating element is only capacitively connected to the conductor structure or to other structures. In an alternative embodiment, the radiating element has at least one galvanic coupling in addition to the at least one capacitive coupling.

In one embodiment, an intermediate medium is present in the region of the coupling parts, wherein the capacitive coupling takes place via the intermediate medium. In one embodiment, the intermediate medium is a dielectric and, alternatively, at least one non-conductor or an insulator. The intermediate medium influences the type of coupling and therefore also the further electrical properties of the antenna device. In a further embodiment, the intermediate medium is mounted between two electrically conductive units, so that the capacitive coupling results. These two at least partially electrically conductive units are formed in one embodiment of a wing element and a web element. In one embodiment, the radiating element is fastened at a distance from the carrier element. The radiator element is in this embodiment z. B. above the support element. In one embodiment, the distance also has an effect on the radiation properties of the antenna device. In one embodiment, the mechanical fastening and the electrical coupling of the radiator element are realized via the same components (eg wing element and / or web element).

In one embodiment, a distance between the radiator element and the carrier element is at least dependent on the wing element. In this embodiment, therefore, the distance between the radiator element and the support element is at least dependent on the configuration of the wing element and in particular of its geometric configuration. In a concomitant embodiment, the wing element is at least a part of a support structure which carries the steel element and thus also keeps at a distance from the support element.

In one embodiment, the conductor structure is applied to the carrier element, so that in one embodiment in conjunction with the aforementioned embodiment, the radiator element is located at a distance above at least a portion of the conductor structure. The conductor structure is thus at least partially covered or protected by the radiator element in this embodiment.

In a further embodiment, the antenna device has at least one web element. The web element is coupled galvanically or capacitively to a feed point of the conductor structure. Furthermore, the web element and the radiating element are capacitively coupled to one another via the coupling point. In this embodiment, the conductor structure has a feed point at which thus electromagnetic signals from the conductor structure off or are coupled into the conductor structure. With this at least one feed point, a web element is galvanically or capacitively coupled. Finally, the web element and the radiating element are capacitively coupled to one another via the coupling point. In one embodiment, the web element and the wing element capacitively couple with each other. In one embodiment, therefore, the coupling between the conductor structure and the radiator element is indirectly via the web element and the wing element. In one embodiment, a distance between the radiator element and the carrier element depends at least on the web element. In this embodiment, the web element thus at least partially serves as a carrier element for the radiator element. In one embodiment, the radiating element is fastened via the wing element or via the wing element and a web element relative to the carrier element. The wing element or the web element allow the electrical - and especially capacitive - connection between the radiator element and the conductor structure. In this embodiment, this is extended to corresponding mechanical properties that allow the wing member and / or the web member to carry the radiator element and thus to keep it at a predeterminable distance from the support element. Therefore, the distance between the radiator element and the conductor structure or, in particular, the carrier element-and possibly further components thereon-can be adjusted in a targeted manner via the wing or web or via the wing and web element in order to obtain certain effects or properties Radiation properties of the antenna device to achieve.

In one embodiment, the radiator element is designed as a surface radiator. A surface radiator differs from the so-called linear radiators (or even linear antennas) in that conducted waves are converted at a fiächenausdehnung in free space waves and vice versa. Area radiators are used, for example, as directional spotlights. The area radiators are thus determined by an area which they span or cover.

In a variant, the radiator element is designed as a surface radiator with an outer contour in the form of an n-corner. Where n is a natural number greater than or equal to three. The surface radiator therefore in this embodiment has the outer contour of a triangle, a quadrangle or any other n-corner. In one embodiment, the outer contour relates to the projection of the radiator element onto the carrier element and therefore in one embodiment onto the surface which is covered by the radiator element. On the sides of the outer contour, therefore, at least one wing element is located between the corners in one embodiment. In an alternative embodiment, the wing element is located between two corners on at least one side. The arrangement of the at least one coupling point or, depending on the configuration of the at least one wing element takes place in an embodiment centrally on the associated side. In a variant, the radiator element is configured as a funnel-shaped surface radiator with a central depression. The radiator element is therefore not flat in this embodiment, but has a lowering, which makes it funnel-shaped. In one embodiment, the radiator element is designed in the sense of a horn antenna. In a further embodiment, the radiating element has at least one recess within its outer contour.

If the radiator element is designed as an n-corner with n sides between the corners, then it provides an embodiment that the at least one Koppeistelie is arranged in the region of one side of the n-corner of the radiator element. In one embodiment, the coupling point is arranged centrally on one side of the n-corner. In a further embodiment, n coupling points are present suitable for the n-angular radiator element, which are each arranged on one side of the surface radiator. In one embodiment, the radiator element is designed as a sheet metal. A sheet has a much larger area than height. Furthermore, the sheet preferably consists of an electrically conductive metal or metal mixture.

In a variant, the radiator element is designed as a monopole. A monopole or a monopole antenna is part of a dipole antenna (or half wave dipole antenna) as a linear antenna. Such antennas have a linear current distribution in the antenna structure. The implementation is, for example, an electrical conductor, which is thin with respect to the wavelength, made of a metallic wire or a metallic rod. A monopole antenna (also known as a quarter-wave antenna or ground plane antenna) is, for example, an antenna rod which is mirrored, for example, by an electrically conductive surface, thereby yielding a half-wave dipole. In an alternative embodiment, the monopole is formed by a flat sheet, wherein the coupling point is then above or below the surface of the monopole. In one embodiment, the radiator element is designed as a rod-shaped monopole. In this case, the coupling point is located along a longitudinal axis of the rod-shaped monopole. .

In one embodiment, the antenna device has a ground surface, which is located on the carrier element in a further embodiment. The ground plane is connected to an electrical ground. In one embodiment, the radiating element has coupling points on several sides. In this case, the radiating element is capacitively coupled to the conductor structure via at least one coupling point. In a further embodiment, the radiator element is capacitively coupled to the conductor structure via more than one coupling point. In one embodiment, the coupling points or the coupling points having wing elements are each located on the sides of a radiating element having an n-angular outer contour.

In one embodiment, the radiating element has four coupling points. In a concomitant embodiment, the radiating element is capacitively coupled to the conductor structure via all four coupling points.

In a further embodiment, the coupling points are arranged symmetrically around the radiator element.

In one embodiment, the radiating element is connected to a signal source (eg in the form of a voltage source) via at least one coupling point. The signal source serves in one embodiment as a signal source for an electromagnetic signal which is emitted via the radiation element.

In an alternative or additional embodiment, the radiating element is connected via at least one coupling point with an open circuit. The coupling via the coupling point takes place in each case capacitively. In the case of idling therefore no coupling with a consumer or an electrical resistance is provided via the coupling point. There is thus an open end.

In a further alternative or additional embodiment, the radiator element is connected via at least one coupling point with a short circuit. In one embodiment, at least two radiator elements are present. In a further embodiment, these at least two radiator elements are coupled to one another - in particular capacitively or via a short circuit, that is to say galvanically. An embodiment provides that the two radiator elements have different distances from the carrier element. The radiator elements are at different heights applied. In one embodiment, the radiator elements overlap - z. B. in the projection perpendicular to the support element - and are free in an alternative embodiment of an overlap. In one embodiment, one of the two radiator elements has a recess, which is located, for example, in the center in the emitter element designed as a surface radiator. In a further embodiment, the other radiating element is arranged in the region of the recess. In one embodiment, one radiator element corresponds to the recess of the other radiator element and, in one embodiment, is additionally located at a different height than the correspondingly associated recess. In the last-mentioned embodiment, as it were, a part of a radiating element has been offset in height. In this case, preferably, the two radiator elements are capacitively coupled together. In a further embodiment, the radiating element has at least one angled portion. In this embodiment, the radiator element z. B. rather rod-shaped or designed as a flat element and has at least one point on an angled or bent course. The antenna device according to the invention therefore provides the advantages of reducing the dimensions of the antenna device and of not losing any or only little in terms of performance, such as radiation behavior with simultaneous impedance matching. On the nature of the capacitive coupling and the components involved in particular radiation properties and impedance matching can be targeted or set in particular.

In particular, there are a variety of ways to design and further develop the antenna device according to the invention. Reference is made on the one hand to the claims, on the other hand to the following description of embodiments in conjunction with the drawings. Show it:

1 shows a spatial and partially transparent representations of a first embodiment of an antenna device, FIG. 2 shows an enlarged detail of the antenna device of FIG. 1, FIG. 3 shows a section through the antenna device of FIG. 1

Fig. 4 shows a further spatial and partially transparent representations of the first

Embodiment of an antenna device,

5 shows several schematic sketches to illustrate the control of the antenna device,

6 shows several principle sketches to illustrate the geometry of the radiating element,

7 shows several schematic sketches for illustrating the capacitive coupling of a radiating element,

8 shows several principle sketches to illustrate the geometry of the wing elements,

9 shows a section through a second embodiment of an antenna device,

10 shows a section through a third embodiment of an antenna device,

11 shows a spatial and partially transparent illustrations of a fourth embodiment of an antenna device,

Fig. 12 is a further spatial and partially transparent representations of the fourth

Embodiment of an antenna device,

Fig. 13 is an enlarged detail of the antenna device of Fig. 11 and

Fig. 12 and

14 shows a section through the antenna device of FIG. 11 or FIG. 12.

The present invention essentially comprises an antenna element - especially a radiator element - as part of the antenna device 1, which is fed via a novel capacitive coupling. As a result, the diameter can be well below half the wavelength of the electromagnetic signals to be emitted or received be reduced and thereby allows a lossless or low-loss impedance matching to significantly less than 100 ohms, z. B. 50 ohms. This succeeds depending on the design up to a quarter of the wavelength and below. It is also possible to dispense with the lossy adjustment elements required in the prior art for the adaptation of radiators smaller than half a wavelength. In addition, no large ground area or a reflector is required for the suppression of the reverberation. As a result, overall the efficiency of the radiator element 4 drops significantly in the prior art. The antenna device 1 is exemplified for operation at 910 MHz. With exemplary dimensions (square support element with 175 mm edge length and square radiator element with 75 mm edge length) and a height of 30 mm, the real part of the base point impedance amounts to approximately 200 ohms for a purely galvanic coupling.

1 shows a three-dimensional representation of an antenna device 1 with a carrier element 2 and a radiator element 4. On the carrier element 2 there is still a ground surface 10. It can be seen that the radiator element 4 has a quadrangular outer contour and lowers in a funnel shape. In this case, the radiator element 4 is a total of spaced from the carrier element 2 and is held or carried here by the four coupling points or by the four wing elements 6.

The area circled in FIG. 1 is shown larger in FIG. Evident are the four wing elements 6, which are located on the sides 40 of the square emitter element 4 here and have at their free ends 60 coupling points 5 for the capacitive coupling. From the support element 2 go at the four feed points 8 four web elements 7. The web elements 7 and the wing elements 6 meet at the coupling points 5 and cause there the capacitive coupling. In the section of Fig. 3 can also be seen how the radiator element 4 is lowered centrally to the carrier element 2 out. Furthermore, it can be seen that the wing elements 6 and thereby the coupling points 5 are located on the sides 40 of the square emitter element 4 here. The wing elements 6 are designed here like the radiating element 4 as plates and are in particular galvanically coupled to the radiating element 4. Between the wing elements 6 and the web elements 7 is in the coupling region 5 each have an intermediate medium 9, which is designed here as a dielectric and thus also Has effects on the capacitive coupling and soft allows a fixation of the radiator element 4 with a defined distance between the wing element 6 and web element 7. Furthermore, here the web elements 7 are electrically coupled to the feed points 8 with the conductor structure on the support element 2. The wing elements 6 and the radiator element 4 or its outer border form an angle 14, which is here at a 90 ° angle. The wing elements 6 are here facing the carrier element 2 and thereby also facing away from the top of the radiator element 4.

The conductor structure 3 is in this case below the radiator element 4 and on the opposite side of the ground surface 10, that is below the support element 2. In an alternative embodiment, the ground surface is located 10 and the conductor structure 3 above the support element 2. In a multi-layer structure, the ground surface 10 or the conductor structure 3 are within any number of layered support elements 2. The web elements 7 or possibly existing elements, the conductor structure with 3 connect the web elements 7, therefore protrude through the carrier element 2, depending on the configuration.

FIGS. 1 to 4 thus show the novel capacitive coupling of the radiation element 4 using the example of a patch with four feed points. By combining a capacitive coupling and the feeding at four suitably chosen points of the radiator element 4, it is possible that the Strahlereiement 4 without a large ground surface 10 or without reflector easily to a desired impedance, often 50 ohms, can be adjusted.

The coupling points 5 are located on the sides 40 of the radiator element 4. For this purpose, the wings (or wing elements 6) are attached to the sides of the Strahierelements 4 and bent downwards. From the support plate 2, four webs protrude - a web (or web element 7) per feed points 8 - and capacitively coupled via an intermediate medium 9 with the wings 7. Thus, the width of the coupling gap between the web 7 and wing 6 can be reduced and also allows a defined distance between web 7 and wing 6. In this case, as an alternative to the dielectric material between web 7 and wing 6, an air gap may be provided. The radiator element 4 and the wing elements 6 can be additionally attached to the webs 7, z. B. screwed, plugged, glued or soldered to the intermediate medium between the web 7 and 6 wings. Due to the width, height and the distance of the coupling point 5 is an almost arbitrary Im- pedanzanpassung possible, which significantly simplifies the development of the antenna element 1, since no lossy matching network is needed.

The shape of the radiating element 4 and the capacitive coupling points 5 generate high field strengths at the coupling points 5, in which the majority of the energy fed in is concentrated. This forces the radiator 4 a wide electrical aperture, whereby the lateral dimensions of the radiator 4 can be significantly reduced.

The coupling via the coupling points 5 on the sides of the respective radiator element 4 can be designed differently. Fig. 5 shows examples of some variants.

Shown are different versions of the architecture, wherein the description is from left to right: a) Different number of feed or coupling points 5:

There can be only one coupling point 5, several or here by way of example up to four coupling points 5. The number of coupling points 5 can also be greater than four. This depends on the geometry of the radiator element 4. In the embodiments shown here, a capacitive coupling takes place over all coupling points 5.

b) With opposite idle (LL, 12) or short circuit (KK, 13) and a connection to a voltage source 1 1, which is also intended to serve as a signal source for the radiated electromagnetic signals here.

The contacts are alternatively present on adjacent sides 40. The connections shown here with an open circuit 12 or a short circuit 13 take place alternatively with a capacitive coupling or capacitor (concentrated component), c) examples of a linear polarization.

The variants are (from left to right):

A linear polarization of the radiator element 4 via two opposing capacitive coupling points 5 and the connection to a signal source 1 first

A dual linear polarization with four coupling points 5 and two signal sources 1 1.

A dual linear polarization with short circuit 13 on one side of the radiator element 4, which faces the coupling point 5 for coupling to a signal source 1 1.

Alternatively, a capacitive coupling or a capacitor (concentrated component) is also used.

A dual linear polarization with no load 1 1. d) A circular polarization with four coupling points 5 and four signal sources 1 1.

e) A dual circular polarization with four coupling points 5 and two signal sources 1 1, each having two feed points 8. The feeding points 8 of a signal source 1 1 are contacted in each case with adjacent coupling points 5.

f) An elliptical polarization with three capacitive coupling points 5 and three signal sources 1 1.

The radiator element 4 can be shaped or configured differently. Fig. 6 shows examples of some variants. Shown in each case is an n-shaped radiator element 4 whose outer contour is formed by the n-corner. Where n is a natural number greater than three.

FIG. 7 shows variants with a monopole as an embodiment of the radiator element 4. Furthermore, different variants for the coupling with web elements 7 are illustrated. In some embodiments, no winged elements are present in the embodiments, so that the radiating element 4 has the at least one coupling point directly on one side 40. The variants of FIG. 7 a) to e) and I) have only the radiator element 4 and the web element 7. The variants of FIGS. 7 f) to k) have the radiator element 4, at least one wing element 5 and at least one web element 7.

Shown in FIG. 7 are the following configurations: a) simple monopole 4 when coupled to the feed substrate,

b) monopole 4 with capacitive coupling with the web element 7 from the left,

c) monopole 4 with capacitive coupling from the right,

d) two monopoles 4, which form a dipole and are coupled twice capacitively, e) two monopolies 4, which are capacitively coupled to one another at the monopole ends and are capacitively coupled to the web elements 6 via the coupling points 5 and f) short circuit of two capacitively coupled monopoles 4, resulting in a dipole or patch. The laterally mounted wing elements 6 are angled at 90 ° in the direction of the web elements 7 at an angle 14.

g) angled monopole 4 (ie with a bend 14) with capacitive coupling from the right with a web element 6,

h) angled monopole 4 with capacitive coupling from the left,

i) double capacitively coupled monopole 4 (dipole), j) dual capacitively coupled monopole 4 (= dipole) with capacitive coupling of the radiator elements,

k) dual capacitively coupled monopole 4 (= dipole) with capacitor (concentrated component) between the radiator elements 4.

Instead of monopolies in the form of wires or z. B. coaxial cables is in alternative embodiments in the Strahlerlementen 4 to surface radiator, z. B. in the form of wide sheet metal elements. This is shown in Fig. 7 I), which allows a rotated by 90 ° view of the embodiment of Fig. 7 b). The side 40 of the radiator element 4 is given here by the base. The web element 7 embodied here as a strip is located on this side 40 through the coupling point 5 in capacitive connection with the radiating element 4.

The wing elements 6 on the radiator element 4 can be designed differently. 8 shows an example of some variants (description in each case again from left to right): a) triangular wing element 6 with arbitrary internal angles <180 °;

b) n-corner with n 3 to a circular or elliptical wing element 6 or a shape similar to a tee (far right);

c) any angled wing elements 6, whose connection to the - not shown here - radiator element would take place in each case at the right end. The coupling points are in each case located on the free ends 60 and the wing elements 6 are connected to the respective radiating element with the ends opposite the free ends (depending on the design).

As well as the wings 6 on the radiator element 4 and the webs 7 can be designed differently. These can vary in width, height, thickness and shape. In addition, they can be straight or angled. Between radiator element 4 and 2 supply plate, in addition to air, an intermediate medium 9 may be inserted, for. As dielectrics, ferrites, ferroelectrics and more. The attachment of the web elements 7 on the supply board as an example of the support member 2 may be realized differently as the attachment of the radiator element 4 to the web elements 7, z. B. screwed, plugged, glued or soldered. FIGS. 9 and 10 show two further embodiments with four points for capacitive coupling between the conductor structure on the carrier element 2 and the radiator element 4. In each case, there is a capacitive coupling between the conductor structure on the carrier element 2 and the web elements 7 on the Feeding points 8. The wing elements 6 are located on the sides of the n-angular radiator element 4 and are bent in the direction of the support element 2. In the embodiment of Fig. 9 there is a galvanic coupling between the web elements 7 and the wing elements 6 in the areas highlighted here with circles and arrows. The coupling points 5 for the capacitive coupling are therefore in this variant in the area of the feed points 8. The wing elements 6 and the web elements 7 are coupled depending on the embodiment galvanic with each other or are made in one piece. In the last variant, therefore, the wing elements 6 with their coupling points 5 virtually open on the free ends 60 on the carrier element 2.

In the embodiment of FIG. 10 there is a capacitive coupling - here in particular via an air gap - between web element 7 and wing element 6, so that between two see also the capacitive coupling point 5 is located. In this case, there is still a capacitive coupling between the web element 7 and the feed point 8. This in contrast to the galvanic coupling between the wing elements 6 and the radiator element 4. The wing elements 6 can be seen here as sheet metal strips, which are attached to the sides of the radiator element 4 and bent downwards. It can also be seen that on the embodiments of wing elements 6 and web elements 7, the distance between the radiator element 6 and the support element 2 or z. B. a ground surface on the support element 2 are adjustable.

In one embodiment, the at least one radiating element 4 is made of a metal sheet, wherein the wing elements 6 and the web elements 7 likewise consist of sheet metal.

FIGS. 11 to 14 show a further embodiment of the antenna device 1 with two radiator elements 4, 4 '. This is, for example, a "stacked patch", eg for dual-band design or extended broadband design. FIG. 11 shows the two differently configured radiator elements 4, 4 ', which are both spaced from the carrier element 2. The higher radiating element 4 (also first radiator element) has a quadrangular outer contour and a central quadrilateral recess 21. Other outer contours are also possible. The second radiator element 4 'is located within the recess 21 and closer to the carrier element 2. In this case, the second radiator element 4' in the illustrated embodiment is also configured quadrangular. Both radiator elements 4, 4 'are designed here plan and are here substantially parallel to the carrier element 2. To recognize the conductor structure 3 in the form of conductor tracks on the carrier element 2 with the four feed points 8, with each of which a web element 7 is connected is. This takes place here matching the four coupling points 5 on the wing elements 6 on the four outer sides 40 of the upper radiating element 4.

FIG. 12 shows the different configuration of the two radiator elements 4, 4 'and their arrangement relative to one another. It can also be seen that the wing elements 6 are located on the sides 40 of the upper or first square radiator element 4 and project from there in the direction of the carrier element 2. The capacitive coupling points 5 are therefore also on the sides. Evident is also the flat course of the wing element, which emanate from the sides of the upper radiator element 4 and are angled here in the direction of the support member 2.

Fig. 13 shows the enlarged section of the part of the antenna device 1 of Fig. 12. From the coupling points 5 project tongue elements 15 to the radiator element 4 'located further in the direction of the support member 2 and therefore also generate an electrical - in particular capacitive - coupling this - second - radiating element 4 '. Overall, therefore, the two beam elements 4, 4 'are capacitively coupled to one another and one of the two radiator elements 4 is capacitively coupled to the conductor structure 3 via the wing elements 6. The section of FIG. 14 shows once again that the upper - first - radiating element 4 rests on the carrier element 2 via the connection of laterally located wing elements 6 and web elements 7 and is capacitively coupled - via the coupling points 5 - to the feed points 8. In this case, between the web elements 7 and the wing elements 6, a dielectric as intermediate medium 9. In the direction of the lower - second - emitter element 4 'extend the tongue elements 15, which also cause an electrical and here capacitive contacting. In addition, it is also applied that the carrier element 2 has a width of 175 mm and the upper radiator element 4 has a side length of 75 mm. In this case, the outer contour of the upper radiator element 4, in particular quadrangular, is approximately 25 mm above the carrier element 2.

The capacitive coupling of at least one radiating element to - preferably four - points offers the following advantages:

The lateral dimensions of the radiator element can be significantly smaller than half the wavelength at the operating frequency. So dimensions of one quarter of the wavelength or less are possible.

The effective aperture of the radiating element is greater than the lateral extent, since the shape of the radiator and the associated position of the coupling points causes a high concentration of energy or field strength at the coupling points.

It is a simple, low-loss impedance matching possible.

Despite the small volume dimensions, it allows a high relative bandwidth, both for the impedance matching and for the directional characteristic. It does not require a large ground plane and / or reflector to reduce the reverberation. The diameter of the ground plane may be, for example, half a wavelength or less.

The radiating element can be constructed very inexpensively, since no expensive substrates such as ceramics are required. In the simplest case stamped and bent parts made of sheet metal (eg aluminum) are sufficient.

Very low height, which accommodates the use of flat antennas, e.g. for UHF RFID applications.

For example, UHF RFID antennas for use in logistics, production or automation offer a technical field of application. These include, for example, gateways, including pulse reading (recording of many transponders in a short time), automated inventory or personal checks (eg healthcare). Another application is provided by mobile terminals for satellite or terrestrial mobile communications. Further applications are in the automotive sector or in the field of networking of vehicles or road users (so-called Car2X). The embodiments described above are merely illustrative of the principles of the present invention. It will be understood that modifications and variations of the arrangements and details described herein will be apparent to others of ordinary skill in the art. Therefore, it is intended that the invention be limited only by the scope of the appended claims and not by the specific details presented in the description and explanation of the embodiments herein.

References:

[1] A. E. Popugaev and R. Wansch, "A novel miniaturization technique in microstrip feed network design," in Proc. of the 3rd European Conference on Antennas and Propagation, EuCAP 2009, Berlin, Mar. 2009, pp. 2309-2131. [2] AE Popugaev, R. Wansch, S. Urquijo, "A NOVEL HIGH PERFORMANCE ANTENNA FOR GNSS APPLICATIONS," in Proc. Of the 2nd Second European Conference on Antennas and Propagation (EuCAP), Edinburgh, UK. Nov. 1-16, 2007.

[3] L. Weisgerber and A. E. Popugaev, "Multibeam Antenna Array for RFID Applications," in Proc. of the 2013 European Microwave Conference (EuMC), Nuremberg, Oct. 2013, pp. 84 - 87.

Claims

claims

Antenna device (1)

with a radiating element (4) for emitting and / or receiving electromagnetic signals,

wherein the radiating element (4) has at least one coupling point (5), wherein the coupling point (5) is connected to one side (40) of the radiator element (4), and

wherein the coupling point (5) is designed for the capacitive input and / or decoupling of electromagnetic signals.

Antenna device (1) according to claim 1,

wherein the antenna device (1) has a conductor pattern (3) for conducting electromagnetic signals, and

wherein the conductor structure (3) and the radiator element (4) via the coupling Stelie (5) are capacitively coupled together.

Antenna device (1) according to claim 1 or 2,

wherein the radiator element (4) has at least one wing element (6), wherein the radiator element (4) and the wing element (6) are galvanically coupled together,

wherein the winged element (6) is arranged on the side (40) of the radiator element (4),

wherein the radiating element (4) and the Flügeleiement (6) form an angle (14) with each other, and

wherein the wing element (6) has the coupling point (5).

Antenna device (1) according to claim 3,

the antenna device (1) having a carrier element (2),

wherein the wing element (6) is angled in the direction of the carrier element (2) from the radiator element (4), and

wherein the coupling point (5) is located at a free end (60) of the wing element (6).

Antenna device (1) according to one of Claims 1 to 4,

wherein in the region of the coupling Stelie (5) an intermediate medium (9) is present, and wherein the capacitive coupling via the intermediate medium (9).

6. Antenna device (1) according to claim 4 or 5,

wherein the radiating element (4) is fixed at a distance from the carrier element (2).

7. Antenna device (1) according to one of claims 2 to 6,

wherein the antenna device (1) has at least one web element (7), wherein the web element (7) is galvanically or capacitively coupled to a feed stile (8) of the conductor structure (3) and

wherein the web element (7) and the radiating element (4) are capacitively coupled to one another via the coupling point (5).

8. Antenna device (1) according to one of claims 1 to 7,

wherein the radiating element (4) is designed as a surface radiator.

9. antenna device (1) according to claim 8,

wherein the radiating element (4) is designed as a surface radiator with an outer contour in the form of an n-corner, and

where n is a natural number greater than or equal to three.

10. Antenna device (1) according to claim 8 or 9,

wherein the radiating element (4) is designed as a funnel-shaped surface radiator with a central depression.

11. Antenna device (1) according to claim 9 or 10,

wherein the coupling point (5) is arranged centrally in the region of one side of the n-corner of the radiator element (4).

12. Antenna device (1) according to one of claims 8 to 1 1,

wherein the radiator element (4) is designed as a sheet metal.

13. Antenna device (1) according to one of claims 1 to 12,

wherein the radiator element (4) is designed as a monopole.

14. Antenna device (1) according to one of claims 2 to 13, wherein the conductor structure (3) on the carrier element (2) is applied.

15. Antenna device (1) according to one of claims 2 to 14,

wherein on the carrier element (2) a ground surface (10) is present.

16. Antenna device (1) according to one of claims 2 to 15,

wherein the radiating element (4) on a plurality of sides (40) coupling points (5) and

wherein the radiating element (4) is capacitively coupled to the conductor structure (3) via at least one coupling point (5).

17. Antenna device (1) according to claim 16,

wherein the radiating element (4) is capacitively coupled to the conductor structure (3) via more than one coupling point (5).

18. Antenna device (1) according to one of claims 1 to 17,

wherein the radiating element (4) has four coupling points (5).

19. Antenna device (1) according to claim 18,

wherein the radiation element (4) is capacitively coupled to the conductor structure (3) via the four Koppeistellen (5).

20. Antenna device (1) according to one of claims 16 to 19,

wherein the Strahierelement (4) via at least one coupling Stelie (5) with a

Signal source (1 1) is connected.

21. Antenna device (1) according to one of Claims 16 to 20, characterized

wherein the radiating element (4) is connected via at least one Koppeistelle (5) with an idle (12), so that there is an open end.

22. Antenna device (1) according to one of claims 16 to 20,

wherein the radiator element (4) via at least one coupling Stelie (5) is connected to a Kurzschiuss (13). 23. Antenna device (1) according to one of claims 1 to 22, wherein the antenna device (1) has at least two radiator elements (4, 4 ').

24. Antenna device (1) according to claim 23,

wherein the two radiator elements (4, 4 ') - in particular capacitive or galvanic - are coupled together.

25. Antenna device (1) according to claim 23 or 24,

wherein the two radiator elements (4, 4 ') have different distances from the carrier element (2).

26. Antenna device (1) according to one of claims 23 to 25,

wherein a radiator element (4) of the two radiator elements (4, 4 ') has a recess (21) and wherein another radiator element (4') of the two radiator elements (4, 4 ') in the region of the recess (21) is arranged.