Dielectric rod antenna having band-stop material

Abstract

The invention relates to a dielectric rod antenna, the dielectric rod antenna comprising: a dielectric rod and an excitation element, in particular a waveguide tube, which receives one end of the dielectric rod in order to excite the dielectric rod, the dielectric rod being configured for a desired frequency at which signals to be transmitted from the dielectric rod antenna are emitted; characterized in that the dielectric rod comprises a band-stop material which suppresses one or more harmonic frequencies of the desired frequency.

Description

Our reference: 250473WO AG Dielectric rod antenna with bandstop material

[0001] Die Erfindung betri^ eine dielektrische Stabantenne sowie ein Herstellungsverfahren für eine die- electric rod antenna.

[0002] Aus dem Stand der Technik ist bekannt, dass dielektrische Stabantennen op^miert sind, um ge- desired frequencies are ideally emitted. They are used when size and weight play a critical role, especially in portable devices and smaller applications. For this purpose, the shape or material of the antenna is often chosen so that it achieves a particularly high radiated power at the desired frequency or in a preferred direction.

[0003] Dadurch, dass in Antennen auch harmonische Frequenzen der gewünschten Frequenz au^reten, Antennas optimized for a desired frequency often also operate at a multiple of the desired frequency, which degrades the signal quality at that frequency. To avoid this, prior art technology often uses frequency filters upstream of the antenna to filter out the harmonic frequencies.

[0004] Aufgabe der Erfindung ist es, eine dielektrische Stabantenne bereitzustellen, welche die Emission suppressed by harmonic frequencies of the desired frequency.

[0005] Die Lösung der Aufgabe erfolgt erfindungsgemäß durch die Ansprüche 1 und 9.

[0006] Die erfindungsgemäße dielektrische Stabantenne weist einen dielektrischen Stab auf, wobei derThe dielectric rod is designed for a desired frequency at which signals to be transmitted by the dielectric rod antenna are emitted; the dielectric rod comprises a band-stop material which suppresses one or more harmonic frequencies of the desired frequency. In a preferred embodiment, the entire dielectric rod consists of the band-stop material. A dielectric rod is part of an antenna that consists mainly of an insulator or dielectric. A preferred dielectric rod antenna comprises several materials with different refractive indices, preferably in the desired frequency, which is suppressed with the help of a special arrangement.

[0007] Eine bevorzugte erfindungsgemäße dielektrische Stabantenne weist weiterhin einen Wellenhohl-A conductor is used to hold one end of the dielectric rod in order to excite the dielectric rod. Other excitation elements are also conceivable that cause the rod antenna to be excited. A waveguide is a structure frequently used in high-frequency technology to guide electromagnetic waves from one place to another. It preferably has a hollow metallic conductor that guides the waves along its length via internal reflection. These conductors preferably operate by trapping waves in a cavity where they propagate with minimal losses and are preferably cylindrical with different base areas. Preferred base areas are: round, rectangular, square, triangular, oval, pentagonal, hexagonal, or n-sided.

[0008] Eine bevorzugte Ausführungsform der dielektrischen Stabantenne ist dadurch gekennzeichnet,that the bandstop material suppresses one or more harmonic frequencies in one, two, or three spatial directions. The spatially dependent suppression of a frequency in one direction can preferably be achieved by a special antenna shape or by a preferred periodic structure of the antenna in one or more of the spatial directions. A preferred structure could, for example, extend in the x-direction in a Cartesian coordinate system and thus inhibit the emission of one or more harmonic frequencies in one or more spatial directions.

[0009] Eine bevorzugte Ausführungsform der dielektrischen Stabantenne weist ein BandsperrenmaterialA periodic structure is defined as a one-dimensional, two-dimensional, or three-dimensional periodic structure. The dimensionality of a periodic structure is determined by the number of spatial directions in which the periodic structure repeats itself. For example, a pattern of parallel lines is one-dimensional, while a diamond pattern has a two-dimensional periodic structure and a cube pattern a three-dimensional periodic structure. A periodic structure comprises several basic cells. A preferred periodic structure comprises at least two media with at least two different refractive indices. The arrangement of the two different media in a preferred periodic structure preferably follows a crystal structure. It is preferred that the framework of the basic cell comprises one solid medium and the other medium is gaseous.

[0010] Eine bevorzugte periodischen Struktur oder Kristallstruktur könnte beispielsweise isometrisch, tet-They can be ragonal, orthorhombic, hexagonal, triclinic, monoclinic, rhombohedral, or diamond-shaped. The type of periodic structure used influences, among other things, the direction in which the harmonics Frequencies are inhibited. For example, it is possible to inhibit different frequencies in different directions by appropriately choosing the periodic structure. This could preferably be achieved by choosing a tetragonal periodic structure, by selecting different sizes of the basic cells in different directions.

[0011] Eine bevorzugte dielektrische Stabantenne weist eine periodische Struktur mit einer oberen Dämp- fungfrequency (^ ^ ) and a lower damping frequency (^ ^ ) on (ribbon edges), where the size of the basic cell (a) is essentially calculated by: where ^ ^ the speed of light, ^ ^the desired frequency and N corresponds to the harmonic frequency to be suppressed. The upper and lower damping frequencies, or band edges (^ ^ ) and (^ ^ ) depend on the chosen periodic structure, the difference between the refractive indices of the media used and ^ ^ . The ribbon edges (^ ^ ) and (^ ^ ) are therefore frequencies that are normalized to the frequency ^ ^ to be specified. In a preferred embodiment, one of the media used is Lu^. In a preferred embodiment, the periodic structure used is tetragonal and corresponds to a Wood-pile structure. In a preferred embodiment, ^ ^ at approximately 5 GHz, still preferably between 1 GHz and 1000 GHz. It is still preferred that the frequency to be attenuated is approximately in the middle of the band edges (^ ^ ) and (^ ^ ) is ordered.

[0012] Eine bevorzugte dielektrische Stabantenne hemmt wenigstens die erste, oder zweite, oder dri^e,or fourth, or fifth harmonic frequency of the desired frequency, or in other words, N lies between 1 and 5, preferably N lies at 3 or 5. As N increases, the wavelengths of the harmonic frequencies are increasingly closer together. Thus, it is preferred that several harmonic frequencies are also suppressed. This is particularly preferred if the upper damping frequency (^ ^ ) and lower damping frequency (^ ^ ) are less far apart than several adjacent harmonic frequencies. In a further embodiment, it is preferred that approximately the mean of the several frequencies to be attenuated is the mean between the upper attenuation frequency (^ ^ ) and lower damping frequency (^ ^ ) lies.

[0013] Eine bevorzugte dielektrische Stabantenne weist eine gewünschte Frequenz bei 5 GHz, oder zwi-The range is 1 GHz and 1000 GHz. The size of the antenna, as well as the size of the base cell, scales with the desired frequency. With commercially available 3D printers, it is possible to create structures with a resolution of down to 0.2 mm. This corresponds to a frequency of up to approximately 1000 GHz. Therefore, printing a preferred dielectric rod antenna poses no problem up to a frequency of 1000 GHz.

[0014] Eine bevorzugte dielektrische Stabantenne weist eine obere Dämpfungsfrequenz (^^) und eine lower damping frequency (^ ^ ) between 1 GHz and 1000 GHz. The attenuation frequency depends on the selected periodic structure. With commercially available 3D printers, it is possible to resolve structures down to 0.2 mm. This corresponds to a frequency up to approximately 1000 GHz. Therefore, printing a preferred dielectric rod antenna represents an attenuation frequency (^ ^ ) and (^ ^) of 1000 GHz poses no problem.

[0015] A preferred dielectric rod antenna has at least one medium in the periodic structure, which is formed from a support material with dielectric particles. It is preferred that the support material with dielectric particles has a sufficiently high permeability so that a bandstop filter is created in the selected structure. For example, when choosing a woodpile structure with background material Lu^, the material should preferably have a permeability of > 6 so that a bandstop filter is created. The higher the permeability contrast, the higher the bandwidth of the suppression. For example, commercially available 3D printing filaments or resins, or powders such as PLA, PET, PETG, TPU, PC, ABS or nylon could be suitable as support materials. The dielectric particles act as the dielectric in the periodic structure. The density of the particles influences the permeability of the structure.The permeability scales with the density of the preferred dielectric particles. It is further preferred that ceramic particles be used as the dielectric particles. It is also preferred that the permeability of the two media used differs as much as possible, as this enables the production of the smallest possible dielectric rods. The permeability of Lu₂ is approximately 1. For this reason, it is preferred that the permeability of at least one of the media lies between 2 and 100 at the desired frequency. An increase in permeability can be achieved, for example, by increasing the dielectric particle concentration in the substrate material or by increasing the amount of material used.

[0016] Ein erfindungsgemäßes Verfahren zur Herstellung einer dielektrischen Stabantenne im addi^venThe manufacturing process, or injection molding, is carried out using a 3D printer or a standard injection molding machine. All common 3D printers or injection molding machines with sufficient size and resolution are suitable. It is also possible to manufacture dielectric rods in several parts and join them together in a subsequent step. For manufacturing the dielectric rod in one piece, the following are suitable: 3D printers are particularly well-suited, as cavities and / or periodic structures can be produced in a single step. An inventive method comprises the following steps: a. Creating a design for a dielectric rod, wherein the dielectric rod is designed for a desired frequency at which signals to be transmitted by the dielectric rod antenna are emitted; characterized in that the dielectric rod has a band-stop material which suppresses one or more harmonic frequencies of the desired frequency. b. Manufacturing the dielectric rod using an additive manufacturing or injection molding process.

[0017] Im Folgenden werden bevorzugte Ausführungsformen der Erfindung anhand von Figuren erläutert.

[0018] Es zeigen:a. Fig. 1 shows a rendering of the dielectric rod antenna according to the prior art (a) and a preferred embodiment (b). b. Fig. 2 shows a preferred basic cell. c. Fig. 3 shows a plot of the attenuation frequencies (^^ ) and (^^ ) as a function of the permittivity difference of the media used for a Wood-pile / tetragonal periodic structure. d. Fig. 4 shows a plot of the attenuation frequencies (^^ ) and (^^ ) as a function of the permittivity difference of the media used for a diamond periodic structure.

[0019] Fig.1 a zeigt einen Hohlleiter 1 sowie einen dielektrischen Stab 2 aus dem Stand der Technik. Fig. 1Figure b shows a waveguide 1 and a preferred embodiment of a dielectric rod 3 according to the invention. The preferred dielectric rod 3 from Figure 1b preferably has a periodic wood-pile structure made of medium 1 (Lu^) and medium 2, an ABS plastic with ceramic particles. A wood-pile structure has layers with parallel rods made of medium 2, each layer of parallel rods being rotated by 90° relative to the previous layer. A rod can be designed as a cylinder with a wide variety of base surfaces. Preferably, the base surfaces are round, rectangular, hexagonal, triangular, or X-shaped.

[0020] Fig. 2 zeigt eine bevorzugte einzelne Grundzelle einer Wood-pile Struktur in einem kartesischenCoordinate system. Fig. 2 shows rods as cylinders with an exemplary rectangular base. Fig. 2 shows a preferred single basic cell of the Wood-pile structure. A basic cell of the Wood-pile structure preferably has four individual cuboids, which are stacked offset from one another. The size of the basic cell in Fig. 2 is proportional to a. The macroscopic Wood-pile structure results from placing several basic cells next to each other in different spatial directions. The preferred basic cell shown is tetragonal. This can be seen from the fact that the basic cell has a different symmetry in the x / y direction than in the z-direction. The cuboids run along the x / y direction, while they are stacked along the z-direction.

[0021] Fig. 3 zeigt einen Plot der Dämpfungsfrequenzen (^^ ) und (^^ ) abhängig vom Permittivitätsunter- The difference in media used for a Wood-pile / tetragonal periodic structure. The solid line preferentially shows the course of (^ ^ ), where the dashed line represents the course of (^ ^) shows. The frequencies which occur between (^ ^ ) and (^ ^ The frequencies located at the gap are attenuated. According to EQ1, the frequencies to be attenuated are placed in this gap, preferably in the gap itself. The solid line B indicates the fractional bandwidth, i.e., a value proportional to the "width" of the band gap.

[0022] Fig. 4 zeigt einen Plot der Dämpfungsfrequenzen (^^ ) und (^^ ) abhängig vom Permittivitätsunter- Schiedder used media for a diamond-periodic structure. The solid line shows the course of (^ ^ ), where the dashed line represents the course of (^ ^ ) shows. The frequencies which are between (^ ^ ) and (^ ^ The frequencies to be attenuated are placed in this gap according to EQ1, preferably mi^g in the gap. Compared to Fig. 3, a different progression of the attenuation frequencies (^^ ) and (^^ ) can be seen. The solid line B shows the fractional bandwidth, i.e., a value proportional to the "width" of the band gap.

Claims

Claims 1. Dielectric rod antenna, wherein the dielectric rod antenna comprises: a dielectric rod; and an excitation element, in particular a waveguide, which receives one end of the dielectric rod in order to excite the dielectric rod, wherein the dielectric rod is designed for a desired frequency at which signals to be transmitted by the dielectric rod antenna are emitted; characterized in that the dielectric rod comprises a band-stop material which suppresses one or more harmonic frequencies of the desired frequency.

2. Dielectric rod antenna according to claim 1, characterized in that the band-stop material suppresses the one or more harmonic frequencies in one, two, or three spatial directions. 3.A dielectric rod antenna according to one of the preceding claims, characterized in that the bandstop material is configured as a three-dimensional periodic structure, wherein a periodic structure comprises several basic cells and the periodic structure comprises at least two media with different refractive indices at the desired frequency.

4. A dielectric rod antenna according to one of the preceding claims, characterized in that the periodic structure has an upper attenuation frequency (^. ^ ) and has a lower damping frequency (^^), where the size of the basic cell (a) is essentially calculated by: where ^ ^ the speed of light, ^ ^the desired frequency and N corresponds to the harmonic frequency to be suppressed.

5. Dielectric rod antenna according to one of the preceding claims, characterized in that at least the first, or second, or third, or fourth, or fifth harmonic frequency of the desired frequency is suppressed, or in other words, that N lies between 1 and 5.

6. Dielectric rod antenna according to one of the preceding claims, characterized in that the desired frequency is at 5 GHz, or between 1 GHz and 1000 GHz.

7. Dielectric rod antenna according to one of the preceding claims, characterized in that the upper attenuation frequency (^ ^ ) and the lower damping frequency (^ ^) between 1 GHz and 1000 GHz.

8. Dielectric rod antenna according to one of the preceding claims, characterized in that one of the media of the periodic structure is formed from a support material with dielectric particles or that the permittivity difference between the media used is at least between 5 and 100 at the desired frequency.

9. Method for manufacturing a dielectric rod antenna according to one of the preceding claims by additive manufacturing or injection molding, wherein the method comprises the following steps: a. Creating a design of a dielectric rod, wherein the dielectric rod is designed for a desired frequency at which signals to be transmitted by the dielectric rod antenna are emitted; characterized in that the dielectric rod is made of a band-stop material which suppresses one or more harmonic frequencies of the desired frequency. b.Production of the dielectric rod using additive manufacturing or injection molding processes.

Images