Antenna for signal transmission using circularly polarized radio signals
A 3D-shaped conductor loop with bent sections above the PCB simplifies manufacturing and enhances efficiency and performance of circularly polarized resonant ring antennas by eliminating feed pins and dielectric interference.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
- Filing Date
- 2025-12-16
- Publication Date
- 2026-06-25
Smart Images
Figure EP2025087275_25062026_PF_FP_ABST
Abstract
Description
[0001] 202407393
[0002] 1
[0003] Description
[0004] Antenna for signal transmission using circularly polarized radio signals
[0005] The invention relates to an antenna for signal transmission using circularly polarized radio signals. Furthermore, the invention relates to a method for operating such an antenna. Finally, the invention relates to an electronic device with a corresponding antenna.
[0006] Directional antennas with circular polarization are used to receive positioning signals from navigation satellites. Particularly in the automotive sector, these antennas need to be compact and cost-effective. Among the wide variety of circularly polarized directional antennas, so-called patch antennas with a diameter of half the wavelength of the radio signals used (half-wavelength patch antenna) and resonant ring antennas with a diameter of one wavelength of the radio signals used (one-wavelength resonant ring antenna) are frequently used in the automotive sector. This paper will focus specifically on resonant ring antennas. This type of antenna is known from the prior art.
[0007] For example, CN 117117494 A discloses a resonant ring antenna whose closed-form conductor loop has been shaped into a meandering form using bend stamping. Plastic support components hold the conductor loop at a desired height above a printed circuit board. To operate the antenna, the conductor loop is connected to contacts on the circuit board via pins. The feed pins are manufactured and attached as separate components to the conductor loop.
[0008] CN 117117493 A discloses a resonant ring antenna with a similar structure, wherein two conductor loops of different diameters are adapted to the 202407393
[0009] The two used frequency bands are combined. The conductor loops are powered by separately shaped feed pins.
[0010] These feed pins for antenna operation must be attached in a separate step during antenna manufacturing and, in particular, positioned correctly. This requires additional guide elements in the manufacturing process, making the overall production of such an antenna more expensive and complex.
[0011] EP 2 592 691 A1 discloses an antenna whose conductor loop is designed as a ring-type radiator by means of a polygonal or circularly closed ring conductor and is arranged essentially horizontally with a height h above a conductive base surface. The ring-type radiator is electromagnetically coupled via vertical radiators extending towards the conductive base surface.
[0012] In the general state of the art, the dielectric support element for supporting the respective conductor loop is also arranged below the conductor loop, i.e., towards the base surface. Since a strong electric field exists both in shunt capacitors and between the conductive antenna components and the top surface of the base surface, any lossy material in this area leads to a reduction in antenna efficiency. Furthermore, even small tolerances in the dielectrics, for example, deviations in the dielectric constant, lead to a shift in the operating frequency, which reduces the antenna performance. This can be solved by a special design of the support elements with cutouts in critical areas. However, this in turn makes the antenna manufacturing process more complex.
[0013] The object of the present invention is to simplify the manufacture of an antenna designed for signal transmission using circularly polarized radio signals and, in particular, to reduce manufacturing costs. 202407393
[0014] 3
[0015] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments of the invention are disclosed by the dependent patent claims, as well as by the description and the figures.
[0016] According to one aspect, the invention relates to an antenna for signal transmission using circularly polarized radio signals, in particular satellite radio signals. That is, the antenna is specifically designed to transmit and receive circularly polarized radio signals.
[0017] The antenna comprises a printed circuit board (PCB), an electrically conductive radiator structure, and a dielectric support element. The radiator structure includes at least one conductor loop with a closed, rotationally symmetrical basic shape. The support element supports the radiator structure at a predetermined distance or height relative to the PCB. This distance is greater than zero. As a result, the radiator structure, and in particular the respective conductor loop, is positioned in a supported state relative to a principal surface of the at least one conductor loop, essentially parallel to or at a predetermined angle of inclination above the PCB. The support element thus supports the radiator structure relative to the PCB in such a way that the respective conductor loop hovers above the PCB. It is held by the support element and therefore does not touch the PCB.The main surface runs parallel or at an angle to the surface of the circuit board.
[0018] The radiator structure has a multitude of bent sections which project at predetermined positions along the main surface, in particular along a principal direction of extension of the main surface, towards the printed circuit board (PCB), where at least one conductor loop is located. The bent sections do not touch the PCB. The bent sections are curved or shaped in the principal direction of extension of the conductor loop towards the PCB. This results in a meandering shape of the conductor loop, which runs, in particular, partly parallel and partly substantially vertically or obliquely to the PCB. 202407393
[0019] 4
[0020] The term "bent section" here refers specifically to the shape of the respective section and does not necessarily imply any manufacturing process. That is, the bent sections have a curved shape. These sections can be manufactured using bending processes such as bending stamping. Alternatively, they can be produced by molding, laser cutting, or printing the conductor loop into a mold, as is known, for example, from Molded Interconnect Devices (MIDs). The bent sections can also be described as three-dimensional areas or molded sections.
[0021] At least two of these bent sections form a feed point for operating or feeding the antenna. This means that the antenna can be supplied with an operating signal or fed via the feed point, and / or a corresponding antenna signal can be tapped from the antenna. The feed point can thus be understood as the electrical connection point or contact point of the antenna.
[0022] Preferably, each conductor loop comprises a total of four to sixteen such bending sections (three-dimensional areas), of which exactly two or at most four are designed as antenna feed surfaces.
[0023] For operation, the circuit board has coupling surfaces for the respective antenna feed area at predetermined positions. In the supported state of the radiator structure, each antenna feed area is positioned above one of the coupling surfaces relative to the circuit board and capacitively coupled to the respective feeding surface for antenna operation. This means that the positions of the coupling surfaces are chosen to correspond to the position of the bending sections. Preferably, the coupling surfaces and antenna feed areas are arranged directly above one another. That is, a base area of the coupling surfaces is preferably congruent with a base area of the bending sections and / or they preferably have overlapping sections. 202407393
[0024] 5
[0025] The invention provides a 3D-shaped conductor loop. The 3D shape, achieved through the bent sections (three-dimensional areas), allows for a reduction in the diameter of the conductor loop compared to a 2D shape without bends. This enables, for example, a particularly compact antenna installation size, ideal for automotive applications. The diameter of the conductor loop depends on the desired frequency range or service and can range from, for example, 12 cm (satellite radio) to 25 cm (navigation). Furthermore, the 3D shape allows for a larger structure for signal generation and reception while maintaining a small package size. This improves the antenna's performance and, in particular, enables a higher bandwidth. Simultaneously, the present antenna requires no additional antenna connections, such as feed pins, to be connected to the conductor loop.Instead, the antenna connection, i.e., the power supply or coupling of the antenna, is made directly via some of the bent sections of the conductor loop itself. This simplifies the manufacturing process and reduces production costs.
[0026] In this context, a conductor loop refers specifically to an electrical conductor that spans an area. The area is defined by the basic shape of the conductor loop. For example, the conductor loop can be configured as a ring conductor with a circular or polygonal base shape. The conductor loop is closed and rotationally symmetric or plane-symmetric. When rotated about a center of rotational symmetry, the basic shape is mapped onto itself. The center of rotational symmetry is located at the center point or geometric centroid of the basic shape of the conductor loop. The conductor loop is made of a conductive material, particularly a metal or alloy, such as coated steel, nickel silver, brass, copper, or aluminum. The conductor loop is preferably a single piece, i.e., formed or manufactured from one piece of material.
[0027] The dielectric support element is to be understood as a dielectric. For this purpose, the support element is made of a dielectric material, i.e., a weakly or not at all dielectric material. 202407393
[0028] The support element is made of 6 electrically conductive materials, such as plastic or polymer. It therefore acts primarily as an electrical insulator. The support element can also be referred to as a plastic carrier, as it "supports" the emitter structure.
[0029] The printed circuit board (PCB) serves as a carrier for electronic components, in this case, for example, the radiator structure and the support element. Of course, the PCB can also include other electrical components, such as components for antenna operation. The components are mechanically attached to the PCB and electrically connected to each other. The PCB includes electrically conductive traces that terminate in contact elements. These contact surfaces serve as electrical connection points for the components. The traces and contacts are mounted on or between an electrically insulating material.
[0030] The antenna can be used for communication with global navigation satellite systems (GNSS). Preferably, the antenna can support, for example, GNSS-L5 / L2 and / or GNSS-L1 communication. Satellite systems used include, for example, GPS (Global Positioning System), GLONASS (Global Navigation Satellite System), Galileo, Beidou, or others. Additionally or alternatively, the antenna can also be used for satellite-based radio systems. A well-known service is, for example, SDARS (Satellite Digital Audio Radio Service). Additionally or alternatively, the antenna can be used for other satellite radio signals, such as receiving or transmitting mobile phone signals.
[0031] Preferably, the antenna is designed for communication with radio signals in a frequency band of 1000 to 3000 MHz. If the radio signals are provided via GNSS, the frequencies are preferably in the range of 1164 MHz to 1300 MHz (lower L-band) and 1559 MHz to 1610 MHz (upper L-band). 202407393
[0032] 7
[0033] The invention includes embodiments that offer additional advantages.
[0034] In one embodiment, the printed circuit board has a conductive surface, which can also be described as an electrically conductive base. This surface faces the radiator structure when supported. The surface includes the respective coupling surfaces, which are designed as galvanically isolated sections of the surface. That is, the coupling surfaces are galvanically isolated from the rest of the surface. For this purpose, the electrically conductive material of the surface around the coupling surfaces can be removed or recessed. A slot or recess can thus be created in the surface around the coupling surfaces. The coupling surfaces can therefore be integrated into the surface like islands or be embedded within it.
[0035] The following section deals with the operation of the antenna. In one embodiment, the radiator structure is provided to be divisible into four symmetrical segments along the main direction of extension of the at least one conductor loop. The division is made, in particular, radially to the center of rotational symmetry of the conductor loop, resulting, either conceptually or fictitiously, in four identical or plane-symmetrical segments.
[0036] Each segment comprises at least one bent section. To operate the antenna, i.e., to transmit or receive circularly polarized radio signals, exactly one bent section, configured as an antenna feed point, is electromagnetically excited in at least two adjacent segments. Alternatively, exactly one bent section, configured as an antenna feed point, can be electromagnetically excited in each of the four segments.
[0037] During electromagnetic excitation, the current distribution of a traveling wave in a single direction along the main surface is established in at least one conductor loop, which acts as a resonator. The phase difference of the transmission wave is between 202407393
[0038] 8
[0039] Antenna feed surfaces are essentially, preferably exactly, 90 degrees. Therefore, two or four of the bending sections are used for antenna operation in adjacent segments to adjust or tap the 90-degree phase shift of the traveling wave.
[0040] Since the bent sections, which are designed as antenna feed points, do not touch the coupling surfaces of the printed circuit board, the bent sections and the coupling surfaces act as capacitors when electromagnetically excited. Thus, when electromagnetically excited, the conductor loop is capacitively coupled to the contact elements.
[0041] For antenna operation, the coupling surfaces can be connected to a signal generator and / or a receiver amplifier via conductor tracks and circuits. To transmit circularly polarized radio signals to a specific satellite, an operating signal can be generated by the signal generator and applied to the conductor loop via the respective coupling and antenna feed surfaces. When the operating signal is applied, the transmission waveform is established. When receiving circularly polarized radio signals from a specific satellite, the conductor loop is also exposed to the radio signal. This transmission waveform is then derived as an antenna signal and can be tapped by the receiver amplifier via the respective coupling and antenna feed surfaces.
[0042] The following describes the design of the bending sections. In one embodiment, each bending section has a base part which, in the supported state, is arranged essentially parallel to the printed circuit board. Furthermore, each bending section comprises two side parts, each of which is directly connected at one end to the base part and at the other end directly to the main surface of the at least one conductor loop. In the supported state, the side parts project from the main surface towards the printed circuit board. 202407393
[0043] 9
[0044] The bending sections can thus be formed in three parts (a base part and two side parts) but preferably as a single piece. The base part provides spacing between the side parts. In the supported state, the base part preferably runs parallel to the main surface of the conductor loop or to the surface of the printed circuit board. For capacitive coupling, the base part and the coupling surfaces, or the conductive surface 21, thus act like parallel capacitor plates. Preferably, the coupling surfaces of the printed circuit board are arranged directly below the respective base part.
[0045] In the supported state, the side sections preferably run perpendicular or obliquely to the main surface of the conductor loop or to the surface of the printed circuit board. That is, from a side view of the conductor loop, particularly a section through the center of rotational symmetry, the bent sections have a rectangular or trapezoidal shape.
[0046] In one embodiment, the two side parts are each attached at one end to opposite edges or sides of the base part and at the other end to the main surface along its principal direction of extension. In its unbent form, the main surface forms the base part, and the side parts thus form a flat base. The conductor loop can therefore be shaped as a long, two-dimensional ring radiator. To create the bending sections, its main surface is bent at predetermined positions along its principal direction of extension, resulting in the desired 3D structure. Bending can be achieved, for example, by bend stamping. Alternatively, the conductor loop can be incorporated as a conductor pattern into a Molded Interconnect Device (MID). The support element can, for example, serve as the carrier for the conductors.Alternatively, it is of course conceivable to cast, laser-cut or print the conductor loop with the bending sections into shape.
[0047] Alternatively, in one embodiment, the two side parts are each attached at one end to opposite ends of a common edge of the base part and at the other end to a common edge 202407393
[0048] The side sections are attached to the main surface. This means that the side sections extend beyond the same edge of the main surface and are attached to the same edge of the base. A two-dimensional template can be used to manufacture the conductor loop, and the loop can be cut or punched from a metal sheet according to the template, for example, using punch stamping. The resulting two-dimensional, open form of the conductor loop can be closed to form the ring radiator, and corresponding sections are bent relative to the side sections, for example, using bending embossing, to create the main surface and the base. This has the advantage of producing very little material waste. Furthermore, bending the individual sections does not introduce tolerances that accumulate over the length of the conductor loop.
[0049] The following section describes the design of the support element. In one embodiment, the support element is attached or arranged below or above the radiator structure in the direction of the circuit board. Additionally or alternatively, the support element is attached or arranged to the radiator structure from the inside or outside, starting from a center of rotational symmetry of the at least one conductor loop.
[0050] Positioning the support element above the radiator structure has proven particularly efficient, as this leaves the space between the radiator structure and the circuit board clear. This eliminates any dielectric material between the radiator structure and the circuit board, allowing for optimal antenna efficiency. Overall, this design makes the antenna more robust against variations in the properties of the support element's dielectric material and against mechanical stresses.
[0051] In one embodiment, the support element is attached or applied to the emitter structure by means of adhesive bonding and / or hot pressing and / or pin crowns and / or lasers and / or MID technology and / or electroplating. The emitter structure and the support element can thus be considered separate components.
[0052] 11
[0053] Parts are manufactured and then connected or fastened together in the manner described.
[0054] Preferably, the support element is designed as a MID circuit carrier. For example, the support element can be manufactured using laser direct structuring (LDS), particularly 3D LDS, or by printing processes or two-shot molding, with its shape being selected such that at least one side replicates the desired shape of the conductor loop. Of course, other known manufacturing processes can also be used, such as MID hot stamping, mask exposure processes, film back injection molding, or direct conductor application. The conductor loop material is then applied to this side of the support element. Once the material has cured or been fully processed, the structure of the conductor loop is formed.
[0055] The following describes special design possibilities of the radiator structure. In one embodiment, the radiator structure comprises at least two conductor loops with a closed, rotationally symmetrical basic shape. The at least two conductor loops have a common center of rotational symmetry, with a first of the at least two conductor loops being arranged within the second of the at least two conductor loops, starting from the center of rotational symmetry. That is, the second conductor loop preferably completely surrounds or encloses the first conductor loop in the respective direction of rotation or principal extent. Particularly preferably, all conductor loops share the respective support element. In particular, more than two conductor loops, for example three or four, are also conceivable.
[0056] Due to their different diameters, the conductor loops can be used for different satellite communications services. For example, the larger of the two conductor loops can be used for the GNSS L5 / L2 band, while the smaller diameter loop is used for the GNSS L1 band or the SDARS band. This allows for 202407393
[0057] 12. Two- or multi-band communication using radio signals is implemented, thus enabling, for example, more accurate navigation.
[0058] In one embodiment, the radiator structure comprises at least one conductor loop with a closed, rotationally symmetrical basic shape. Furthermore, the radiator structure comprises at least one electrical conductor with a monopole antenna structure. The electrical conductor can thus have a straight basic shape or a rod shape. The at least one electrical conductor is arranged within the at least one conductor loop, starting from a center of rotational symmetry of the loop.
[0059] Preferably, at least one electrical conductor is arranged at the center of rotational symmetry. Particularly preferably, all conductor loops and all conductors share the respective support element.
[0060] Preferably, the at least one electrical conductor is arranged vertically to the circuit board in the supported state.
[0061] This method exploits the fact that at least the first conductor loop operates using circularly polarized waves, meaning there is essentially no electric field at the center, i.e., at the center of rotational symmetry, of a typical redundant ring antenna with a diameter of approximately one wavelength. The conductor with the monopole antenna structure can therefore be used, for example, for mobile communication.
[0062] Of course, a combination of the two aforementioned embodiments is also conceivable, in which two or more conductor loops with a closed rotationally symmetrical basic shape are arranged overlapping each other and an electrical conductor with a monopole antenna structure is provided in the center of rotational symmetry.
[0063] According to one aspect, the invention relates to an electronic device with an antenna, as described above by way of example. The electronic device can be, for example, a component of a motor vehicle, such as a mobile communication module and / or a navigation module. (202407393)
[0064] 13
[0065] The motor vehicle is preferably a car, in particular a passenger car or bus, or a truck or motorcycle. Alternatively, the electronic device can be, for example, a mobile device such as a smartphone or tablet, a smartwatch, or another smart device. Alternatively, the electronic device can be, for example, a navigation device, in particular a portable navigation device.
[0066] According to one aspect, the invention relates to a method for operating an antenna, as described above by way of example. In this method, at least one conductor loop of the antenna is electromagnetically excited, thereby capacitively coupling the respective antenna feed surface, in the supported state of the radiator structure, with the respective contact surface for operating the antenna.
[0067] As described in one embodiment of the antenna, for operation in two or four adjacent segments, one antenna feed surface is electromagnetically excited. During electromagnetic excitation, the current distribution of a traveling wave in the direction of travel is established in the at least one conductor loop, which acts as a resonator. The phase difference of the transmission wave between the antenna feed surfaces is essentially, preferably exactly, 90 degrees.
[0068] The invention also includes further developments of the inventive method and the inventive electronic device, which have features already described in connection with the further developments of the inventive antenna. For this reason, the corresponding further developments of the inventive method and the inventive electronic device are not described again here.
[0069] The invention also includes combinations of the features of the described embodiments.
[0070] An embodiment of the invention is described below. Figure 202407393 shows this.
[0071] 14
[0072] Fig. 1 shows a schematic representation of an antenna for signal transmission using circularly polarized radio signals according to a first embodiment;
[0073] Fig. 2 shows a schematic representation of an antenna for signal transmission using circularly polarized radio signals according to a second embodiment;
[0074] Fig. 3 shows a schematic representation of a corresponding antenna according to a third embodiment with a two-port feed;
[0075] Fig. 4 shows a schematic representation of a corresponding antenna according to a third embodiment in a four-port feed;
[0076] Fig. 5 shows a schematic representation of a corresponding antenna from a side view with a dielectric support element according to a first embodiment;
[0077] Fig. 6 shows a schematic representation of the antenna according to Fig. 5 with a dielectric support element according to a second embodiment;
[0078] Fig. 7 is a schematic representation of the antenna with the dielectric support element according to Fig. 6 from a perspective view;
[0079] Fig. 8 shows a schematic representation of an electrically conductive radiator structure of a corresponding antenna according to an exemplary embodiment;
[0080] Fig. 9 shows a schematic representation of the electrically conductive emitter structure according to Fig. 8 and a dielectric support element according to an embodiment; 202407393
[0081] 15
[0082] Fig. 10 is a schematic representation of a corresponding antenna with an electrically conductive radiator structure comprising two conductor loops, from a top view in perspective; and
[0083] Fig. 11 is a schematic representation of the antenna with the electrically conductive radiator structure and the two conductor loops according to Fig. 10 from a perspective view from below.
[0084] The embodiment described below is a preferred embodiment of the invention. In this embodiment, the described components each represent individual features of the invention that can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiment can also be supplemented by other features of the invention already described.
[0085] In the figures, functionally identical elements are each provided with the same reference symbols.
[0086] Fig. 1 shows a schematic perspective view of an antenna 10 for signal transmission using circularly polarized radio signals. The antenna 10 can thus receive or transmit circularly polarized radio signals, in particular satellite radio signals. The antenna 10 is specifically designed as a directional antenna, a so-called ring antenna with a circumference of approximately one wavelength of the satellite radio signals (one-wavelength resonant ring antenna), as is frequently used, for example, in the automotive sector for satellite navigation or satellite radio (SDARS). For example, the antenna 10 can be used for position determination using GNSS, for example, for the GNSS L5 / L2 band and / or the GNSS L1 band. 202407393
[0087] 16
[0088] The antenna 10 comprises a printed circuit board 20, an electrically conductive radiator structure 11, and a dielectric support element 30 (not yet shown in Figures 1 to 4). The radiator structure 11 comprises at least one, and in the present embodiment exactly one, conductor loop 12. However, there are also embodiments in which the radiator structure 11 has more than one conductor loop 12, for example, two, three, or four conductor loops. The conductor loop 12 according to Figure 1 comprises a closed, rotationally symmetrical basic shape and is, for example, circular in this example. Of course, the conductor loop 12 can also have a different, in particular polygonal, basic shape, provided that it is rotationally symmetrical. In the present embodiment, the conductor loop 12 is configured as a ring conductor.
[0089] The conductor loop 12 is supported by the dielectric support element 30 at a predetermined distance d from the circuit board 20, in particular its surface 21, so that it hovers essentially parallel to the circuit board 20 with respect to its main surface 12a. It therefore does not touch the circuit board 20 in the supported state.
[0090] The conductor loop 12 comprises a plurality of bent sections 13 which project from the main surface 12a towards the printed circuit board 20 at predetermined positions along a principal extension direction R, which is defined in particular by a circumference of the conductor loop 12. The bent sections 13 are formed extending from the main surface 12a towards the printed circuit board 20.
[0091] This results in a meandering shape for the conductor loop 12 along its main direction of extension R. In particular, this allows for a very small package size for the antenna 10 and the conductor loop 12. The meandering shape allows the circumference of the conductor loop 12 to be reduced compared to a corresponding conductor loop without bends. The circumference can therefore be smaller than a wavelength of the radio signals. This corresponds to the required size for such ring radiators and makes the antenna 10 more compact than conventional ring radiators, as shown in 202407393.
[0092] 17 simultaneously maintains the desired radiation pattern or radiation characteristic of the antenna 10 for circular polarization (in the direction of the zenith, i.e., in particular perpendicular to the surface 21 of the circuit board 20).
[0093] The number of bending sections 13 can vary from four to sixteen. The number depends in particular on the desired dimensions and height of the entire structure, as well as the desired operating frequency for radio communication (for example, for GNSS-L5 / L2 or GNSS-L1 or SDARS).
[0094] Each bending section 13 is formed in three parts. The bending section 13 comprises a base part 13a and two side parts 13b. In the embodiment shown in Fig. 1, the side parts 13b are attached at one end to opposite edges 13c, 13d of the base part 13a. At the other end, the respective side parts 13b are attached to the main surface 12a along the main direction of extension R. To achieve this shape, the conductor loop 12 can, for example, be stamped or cut out in one piece as a two-dimensional ring from a metal plate, for example by means of stamping. The bending sections 13 are then produced by stamping or bending the desired shape of the bending sections 13 into the conductor loop 12, starting from the main surface 12a, for example by means of bending.
[0095] Alternatively, the conductor loop can be cast, printed, or laser-cut into shape. For this, MID technology, especially 3D-MID technology, can be used.
[0096] In the supported state, the base part 13a runs essentially parallel to the surface 21 of the printed circuit board 20 and the main surface 12a. The side parts 13b extend from the main surface 12a in the direction of the surface 21. In the embodiment according to Fig. 1, the side parts 13b preferably run perpendicular to the main surface 12a or to the surface 21. This results in an essentially rectangular basic shape for the bent section 13. 202407393
[0097] 18
[0098] Alternatively, the side sections 13b can also project obliquely to the main surface 12a, so that, for example, a side view reveals a trapezoidal shape of the bending section 13. Alternatively, the base section 13a can be oriented at an angle to surface 13. Due to their shape, the bending sections can also be referred to as U-inserts.
[0099] Fig. 2 shows another embodiment of a corresponding antenna 10 according to Fig. 1, where the conductor loop 12 has a rectangular basic shape. Of course, another rotationally symmetrical basic shape would also be conceivable. Since the conductor loop 12 is rotationally symmetrical about a center of rotational symmetry Z, it can be conceptually divided into four identical segments.
[0100] The segments are divided into I, II, III, and IV. In the present embodiment, each of these segments I, II, III, and IV comprises exactly one bending section 13. Depending on the total number of bending sections 13, each segment can, of course, also comprise two or more bending sections 13. The bending sections 13 within a segment I, II, III, and IV can have different geometries.
[0101] For the operation of antenna 10, i.e. for signal transmission using radio signals, at least two adjacent segments I are required.
[0102] In segments II, III, and IV, exactly one of the bent sections 13 is configured as an antenna feed surface 14. As shown in Fig. 2, exactly the two bent sections 13 of segments I and II are configured as antenna feed surfaces 14. The circuit board 20 now has coupling surfaces 22 at predetermined positions that correspond to the positions of the antenna connections 14. In the supported state, the antenna feed surfaces 14 are arranged directly above the respective coupling surfaces 22 and capacitively coupled to them for the operation of the antenna 10.
[0103] As shown in Fig. 2, the coupling surfaces 22 are embedded in the electrically conductive surface 21 of the circuit board 20, so to speak, in the form of islands. That is, the coupling surfaces 22 are galvanically isolated from the rest of the surface 21. For this purpose, slots 23 are provided in the material of the surface 21. (An 202407393)
[0104] 19 at the location of the slots 23 the conductive material of the surface 21 is interrupted, thus creating galvanic isolation.
[0105] The antenna operation can now be explained in more detail with reference to Figures 3 and 4. Figures 3 and 4 show exemplary embodiments of the antenna 10 according to Figure 2. In this embodiment, however, the conductor loop 12 has, for example, three bending sections 13 per segment I, II, III, IV. Of course, a different number of bending sections 13 would also be conceivable.
[0106] Fig. 3 shows an example of a two-port feed for the antenna 10. The antenna 10 is thus operated or fed via two of the coupling surfaces 22. For this purpose, a bent section 13 in segments I and IV is designed as an antenna feed surface 14. The circuit board 20 accordingly has two galvanically isolated coupling surfaces 22.
[0107] Fig. 4 shows an example of a four-port feed for the antenna 10. The antenna 10 is thus operated or fed via four of the coupling surfaces 22. For this purpose, exactly one bent section 13 is formed as an antenna feed surface in each of the segments I to IV. The circuit board 20 accordingly has four galvanically isolated coupling surfaces 22.
[0108] For antenna operation, the respective conductor loop 12 can now be electromagnetically excited by means of the antenna feed surfaces 14. Electromagnetic excitation is achieved, for example, by exciting the conductor loop 12 with a corresponding radio signal. Alternatively, the conductor loop 12 can be electromagnetically excited, for example, by coupling a corresponding signal into the conductor loop 12 using a signal generator connected to the respective coupling surface 22 via conductor tracks.
[0109] Under electromagnetic excitation, the current distribution of a traveling line wave in the conductor loop 12, which acts as a resonator, is in a single direction of rotation, i.e., for example, the main propagation direction R, 202407393
[0110] 20 along the main surface 12a. The phase difference of the wave between the antenna coupling surfaces is exactly 90 degrees. This phase difference is achieved in particular by the positioning of the antenna connections 14 used. During electromagnetic excitation, the base parts 13a, which are aligned in particular parallel or at an angle to the coupling surfaces 22, act so that the conductor loop 12 is capacitively coupled to the circuit board 20.
[0111] The antenna is thus operated using the conductor loop 12 itself, and no additional connections between the conductor loop 12 and the circuit board 20 are required. This simplifies the manufacturing process, reduces mechanical deviations, increases the robustness of the entire antenna 10, and, in particular, eliminates soldering processes, thereby reducing overall manufacturing costs.
[0112] The function of the dielectric support element 30 will now be described in more detail with reference to Figures 5 and 6. Figures 5 and 6 show the antenna 10, for example, according to Figure 2 or Figure 3, in a side sectional view.
[0113] According to the embodiment shown in Fig. 5, the support element is arranged below the conductor loop 12, extending from the conductor loop 12 towards the printed circuit board 20. The conductor loop 12 rests, in particular with the base parts 13a of the bending sections 13, on one side of the support element 30. On the opposite side, the support element 30 rests on the surface 21 of the printed circuit board 20. The thickness of the support element determines the distance d that the conductor loop 12 has from the surface 21 in the supported state.
[0114] In contrast, according to the embodiment shown in Fig. 6, the support element 30 is arranged above the conductor loop 12. The support element 30 thus rests on the main surface 12a of the conductor loop 12. Therefore, there is no dielectric material between the circuit board 20 and the conductor loop 12. 202407393
[0115] 21
[0116] In particular, there is only air between them. The specified distance d is achieved by the fact that the support element 30 has feet 31 or supports with which it is attached directly to the surface 21. The feet 31 represent a vertical extension, i.e., an extension in the direction of the circuit board 20 compared to the dimension of the conductor loop 12.
[0117] This variant of the arrangement of the support element 30 is particularly advantageous because the dielectric material, especially a plastic material, does not affect the most critical areas of the antenna 10. These include, for example, the area on the underside of the radiator structure 11 and the circuit board 20, the parallel capacitors formed by the base parts 13a of the bending sections 13 and the contact elements 22. This reduces the influence of variations in the dielectric material as well as mechanical variations during the manufacture of the support element 30. The antenna design is thus made more robust.
[0118] In alternative embodiments not shown, the support element 30 can, for example, also be attached laterally, for example on an inner or outer side, starting from the center of rotational symmetry Z on the conductor loop 12. The support element 30 can be attached to the emitter structure 11 by means of adhesive bonding and / or hot pressing and / or pin crowns and / or lasers and / or electroplating and / or MID technology.
[0119] When using MID technology, the support element 30 is manufactured as a circuit carrier, for example, by injection molding. Conductor trace patterns are incorporated or formed into the support element 30 using specific processes. Suitable methods include laser structuring, printing processes for printed circuits (printed electronics), or two-shot molding. The conductor trace pattern exhibits the desired structure of the conductor loop 12. The material of the conductor loop 12 can then be introduced into the conductor trace pattern to form the conductor loop 12.
[0120] The distance d does not need to be identical over the entire area of the conductor loop 12. For example, the conductor loop 12 can have bending sections 13 202407393
[0121] 22 exhibit sections that have less distance to the circuit board 20 than other bending sections.
[0122] Fig. 7 shows another embodiment of the antenna 10 according to Fig. 3 or Fig. 4 with the support element 30 attached. The support element 30 is attached to the conductor loop 12 from above, as shown, for example, in Fig. 6. Of course, a different positioning of the support element 30 and / or a different basic shape of the conductor loop 12 would also be conceivable. In the embodiment according to Fig. 7, the conductor loop 12 and the support element 30 are manufactured, for example, using MID technology. Naturally, other manufacturing methods would also be conceivable.
[0123] Fig. 8 shows an alternative embodiment for the shape of the conductor loop 12 compared to the embodiments in Figs. 1 to 4. Here, the desired rotationally symmetrical basic shape of the conductor loop 12 is achieved by attaching the two side parts 13b of the respective bending section 13 together at one end to opposite ends of an edge 13e of the base part 13a. At the other end, the side parts 13b are attached to a common edge 12b of the main surface 12a.
[0124] For this purpose, the conductor loop 12 can, for example, be punched or cut out of a metal plate as a two-dimensional shape according to a suitable template. The two-dimensional shape can then be closed to form the ring radiator. To create the main surface 12a and the base part 13a, the corresponding sections of the two-dimensional shape can then be bent relative to the side parts 13b. This results in a particularly material-saving and cost-effective alternative for forming the conductor loop 12.
[0125] As shown in the embodiment according to Fig. 8, the side parts 13b preferably have a certain width (dimension perpendicular to the main surface 12a) and thickness (dimension horizontal to the main surface 12a), wherein the width is equal to or greater than the thickness. The vertical side parts 13b are aligned parallel or at an angle to each other, such that their 202407393
[0126] The 23 largest surfaces lie in the same plane. They are connected to the horizontal base part 13a at its longest side, which forms the common edge 13e. The largest surface of the base part 13a is aligned parallel to or at an angle to the circuit board 20. According to the embodiment shown in Fig. 8, the main surface 12a and the respective base part 13a are bent towards the center of rotation of the conductor loop 12 to achieve the desired shape. Of course, bending in the other direction is also conceivable.
[0127] In Fig. 8, for example, the conductor loop 12 has a rectangular base shape. Of course, a conductor loop 12 with a different polygonal base shape can also be used.
[0128] Fig. 9 shows a schematic representation of the antenna 10 according to Fig. 8 with the support element 30. The support element 30 is, in particular, attached to the conductor loop 12 from above, as shown, for example, in Fig. 6. Of course, another positioning of the support element 30 would also be conceivable. As can be seen in Fig. 9, the shape of the support element 30 is not adapted to the shape of the conductor loop 12 to the same extent as, for example, in Fig. 7. In this case, a different method than the MID technology mentioned above was chosen for manufacturing and attaching the two components to each other.
[0129] Figures 10 and 11 show an embodiment of the antenna 10, for example, according to Figure 7. Here, however, the radiator structure 11 has two conductor loops 12c, 12d instead of one conductor loop 12. Both conductor loops 12c, 12d have a closed, rotationally symmetrical, rectangular basic shape and are arranged around a common center of rotational symmetry Z. Of course, a different basic shape for the conductor loops 12c, 12d would also be conceivable. The first conductor loop 12c is arranged within the second conductor loop 12d, starting from the center of rotational symmetry Z. Both conductor loops 12c, 12d share a common support element 30. According to the embodiment in Figure 10, the support element 30 is mounted above the radiator structure 11. Of course, a different positioning of the support element 30 would also be conceivable. 202407393
[0130] 24
[0131] Fig. 11 shows the radiator structure 11 with the support element 30 according to Fig. 10 from a view from below, i.e. from the direction of the circuit board 20. Here the ring arrangement of the conductor loops 12c, 12d is even more clearly visible.
[0132] Two conductor loops 12c, 12d with different diameters are used. These two conductor loops 12c, 12d are intended for different frequency bands. For example, the larger conductor loop 12d can be used for the GNSS L5 / L2 band, while the smaller conductor loop 12c is used for the GNSS L1 band or the SDRAS band. In the embodiments shown in Fig. 7, the conductor loops 12c, 12d and the support element 30 are manufactured, for example, using MID technology. Of course, other manufacturing methods would also be conceivable.
[0133] It is of course conceivable that one or more further conductor loops are enclosed by the radiator structure 11. For example, an even narrower ring antenna, designed for the SDRAS band, for instance, could be arranged within the first conductor loop 12c, starting from the center of rotational symmetry Z.
[0134] Alternatively, an electrical conductor with a rotationally symmetrical basic shape other than the closed one can be used. For example, an electrical conductor with a monopole antenna structure can be used. This can be used, for example, for mobile communication. For this purpose, the conductor can be arranged perpendicular to the circuit board at the center of rotational symmetry Z. The same support element 30 can be used for all conductor loops 12 and conductors. Alternatively, each conductor loop 12c, 12d, or each conductor, can be held by a separate support element 30.
[0135] The antenna 10, according to the described embodiments, can be installed or used in an electronic device. The electronic device can be, for example, a vehicle component, a mobile device, a navigation device, or a radio. 202407393
[0136] 25
[0137] Overall, the exemplary embodiments show a circularly polarized resonant ring antenna with capacitive feed.
[0138] 202407393
[0139] 26
[0140] Reference symbol list
[0141] 10 Antenna
[0142] 11 Radiator structure
[0143] 12 conductor loops
[0144] 12a Main area
[0145] 12b Edge
[0146] 12c conductor loop
[0147] 12d conductor loop
[0148] 13 Bending section
[0149] 13a Basic part
[0150] 13b Side panels
[0151] 13c edge
[0152] 13d edge
[0153] 13th edge
[0154] 14 Antenna feed area
[0155] 20 circuit boards
[0156] 21 surface
[0157] 22 coupling area
[0158] 23 slots
[0159] 30 support element
[0160] 31 feet d distance
[0161] R Direction of rotation
[0162] Z Center of rotational symmetry
[0163] Segment I
[0164] Segment II
[0165] Segment III
[0166] IV Segment
Claims
202407393 27 Patent claims 1. Antenna (10) for signal transmission using circularly polarized radio signals, comprising: - a printed circuit board (20), an electrically conductive emitter structure (11) and a dielectric support element (30), wherein - the radiator structure (11 ) comprises at least one conductor loop (12) with a closed, rotationally symmetric basic shape, - the support element (30) supports the emitter structure (11) at a predetermined distance from the circuit board (20), so that the emitter structure (11) is arranged in a supported state with respect to a main surface (12a) of the at least one conductor loop (12) substantially parallel above the circuit board (20), - which at least one conductor loop (12) has a plurality of bending sections (13) which project at predetermined positions along the main surface (12a) of the at least one conductor loop (12) relative to it in the direction of the circuit board (20), characterized in that - at least two of the bending sections (13) form a respective antenna feed area (14) for operating the antenna (10), and to this end - the circuit board (20) has coupling surfaces (22) for the respective antenna feed surface (14) at predetermined positions, wherein - the respective antenna feed surface (14) in the supported state of the radiator structure (11) is arranged above one of the coupling surfaces (22) and is capacitively coupled to the respective coupling surface (22) for the operation of the antenna (10).
2. Antenna (10) according to claim 1, wherein the circuit board (20) has an electrically conductive surface (21) which, in the supported state, faces the radiator structure (11), wherein the surface (21) comprises the respective coupling surfaces (22) and the respective coupling surfaces (22) are designed as galvanically isolated sections of the surface (21). 202407393 28 3. Antenna (10) according to one of the preceding claims, wherein the radiator structure (11) is divisible along the main surface (12a) of the at least one conductor loop (12) into four symmetrical segments (I, II, III, IV), wherein each of the segments (I, II, III, IV) comprises at least one bending section (13), wherein for operating the antenna (10) in at least two adjacent segments (I, II, III, IV) a bending section (13), which is designed as an antenna feed surface (14), is electromagnetically excitable.
4. Antenna (10) according to one of the preceding claims, wherein the respective bending section (13) comprises a base part (13a) which, in the supported state, is arranged substantially parallel or at a predetermined angle of inclination above the printed circuit board (20), and the respective bending section (13) comprises two side parts (13b) which are each directly connected at one end to the base part (13a) and at the other end directly connected to the main surface (12a) of the at least one conductor loop (12) and project from the main surface (12a) in the supported state towards the printed circuit board (20).
5. Antenna (10) according to claim 4, wherein the two side parts (13b) are each attached at one end to opposite edges (13c, 13d) of the base part (13a) and at the other end to the main surface (12a) along its main extension direction (R).
6. Antenna (10) according to claim 4, wherein the two side parts (13b) are each attached at one end to opposite ends of an edge (13e) of the base part (13a) and at the other end to a common edge (12b) of the main surface (12a).
7. Antenna (10) according to one of the preceding claims, wherein the support element (30) is attached to the radiator structure (11) below or above in the direction of the circuit board (20), or the support element (30) is attached to the radiator structure (11) from the inside or outside starting from a center of rotational symmetry (R) of the at least one conductor loop (12). 202407393 29 8. Antenna (10) according to one of the preceding claims, wherein the support element (30) is attached to the radiator structure (11) by means of gluing and / or hot pressing and / or pin crowns and / or lasers and / or electroplating and / or MID technology (Molded Interconnect Device).
9. Antenna (10) according to one of the preceding claims, wherein the radiator structure (11) has at least two conductor loops (12c, 12d) with a closed, rotationally symmetrical basic shape, wherein the at least two conductor loops (12c, 12d) have a common center of rotational symmetry (R) and a first of the at least two conductor loops (12c) is arranged from the center of rotational symmetry (R) within a second of the at least two conductor loops (12d).
10. Antenna (10) according to one of the preceding claims, wherein the radiator structure (11) has at least one conductor loop (12) with the closed, rotationally symmetric basic shape, and the radiator structure (11) has at least one electrical conductor with a monopole antenna structure, wherein the at least one electrical conductor is arranged starting from a rotational symmetry center (R) of the at least one conductor loop (12) within the at least one conductor loop (12).
11. Electronic device with an antenna (10) according to one of the preceding claims.
12. Method for operating an antenna (10) according to any one of the preceding claims 1 to 10, wherein the at least one conductor loop (12) is electromagnetically excited and thereby the respective antenna feed surface (14) in the supported state of the radiator structure (11) is capacitively coupled with the respective contact element (22) for operating the antenna (22).