Wideband direction-finding antenna

Abstract

The invention relates, inter alia, to an antenna apparatus comprising: an electrically conductive base plate; and an electrical conductor which protrudes at both its ends from the base plate, thereby forming a frame together with the base plate.

Description

[0001] Broadband direction finder antenna

[0002] The disclosure relates to an antenna device, a circular group antenna and a manufacturing method for an antenna device.

[0003] US 2,247,743 discloses a broadband shortwave antenna with a horizontal loop having one turn, a transmission line connected to one side of the loop, a resistor connected in series in the loop opposite the transmission line, wherein the dimension of the loop between points on the loop in the middle between the resistor and the transmission line is less than half the length of the operating wave, such that the loop has a maximum response in the direction of the transmission line and a lower response in every other direction.

[0004] This has a large overall height.

[0005] The aforementioned problems are to be at least partially resolved. The overall height is to be reduced while maintaining similar or improved technical specifications. Furthermore, simple manufacturing, low weight, and cost-effective production are to be achieved.

[0006] The aforementioned advantages are achieved at least partially through features of the independent claims. Dependent claims describe preferred embodiments of the invention.

[0007] Specifically, the disclosure comprises an antenna device comprising: an electrically conductive base plate (hereinafter referred to as the base plate); and an electrical conductor extending from the base plate at both ends, thus forming a frame with the base plate. The electrical conductor can form an antenna. Due to the shape of the electrical conductor, this can be described as a half-loop antenna. The base plate can function as a ground plane. The electrical conductor can be (electrically) connected to the base plate at one or both of its ends.

[0008] Because the electrical conductor protrudes from the base plate at both ends, a framed area is created between the electrical conductor and the base plate. The electrical conductor is preferably continuous between its two ends. Furthermore, the electrical conductor preferably does not form a closed loop. The electrical conductor, together with the base plate, forms a closed loop (frame).

[0009] In the prior art, the base plate is generally considered a disruptive element. In the present disclosure, the base plate is advantageously used as a mass element.

[0010] This design allows for a lower overall height (maximum distance of the electrical conductor from the base plate). It also enables simple and cost-effective manufacturing.

[0011] Furthermore, the antenna device may include electronic elements that are positioned on a side of the base plate facing away from the electrical conductor.

[0012] One or both ends of the electrical conductor can be connected through the base plate to one or more electronic components. This can be an alternative or additional connection to the electrical conductor being directly connected to the base plate.

[0013] Because the electronics are located on the back of the base plate and the base plate has ground potential, the antenna is (almost) not affected by the components (in an unintended way, i.e., by radiation and / or other than by direct control).

[0014] Electronic components may include one or more of the following: (active) electronics, low-noise preamplifiers, calibration antenna switches, etc. Furthermore, the antenna device may form a direction-finding antenna.

[0015] The direction-finding antenna is more sensitive in certain directions (better reception and / or stronger signal strength when transmitting). The more sensitive directions are preferably perpendicular to the extent of the electrical conductor (i.e., parallel and / or antiparallel to a surface normal of the area formed by the frame).

[0016] Furthermore, the electrical conductor can comprise three sections, each of which is at a right angle to an adjacent of the three sections and lies together in one plane.

[0017] Thus, the electrical conductor can form three sides of a rectangle (if the ends of the conductor extend at right angles from the base plate). Alternatively, other shapes are also possible (or parts of other shapes if the part facing the base plate is omitted), such as a circle, a partial circle, a triangle, or a polygon. A shape consisting of three sides of a quadrilateral with non-right-angled corners is also possible.

[0018] Furthermore, two outer sections of the three sections can be shorter than a middle section of the three sections.

[0019] This allows for a lower overall height. In the case of a rectangle, this results in a low, elongated shape. The low profile results from the two outer sections being shorter. The elongated profile results from the middle section being longer.

[0020] Furthermore, each of the three sections can be shorter than the wavelength of an electromagnetic wave to be coupled.

[0021] This allows the antenna device to achieve unidirectional radiation (in the direction of the feed point). The antenna device can also have a bidirectional directional characteristic.

[0022] Furthermore, the electrical conductor can protrude orthogonally from the base plate at its ends. Alternatively, non-right angles (not equal to 0°) between one or both ends of the electrical conductor and the base plate are also possible.

[0023] Furthermore, the two ends of the electrical conductor can be three times as far apart as the extension distance in which the electrical conductor extends perpendicularly away from the base plate in one direction.

[0024] In the case of the rectangular shape (the frame), the shape is three times as long (parallel to the surface of the base plate) as it is high (orthogonal to the surface of the base plate). Such an optimized ratio (3:1) was investigated via antenna simulation, depending on both the side lengths. The maximum possible area is utilized; that is, the effective area of ​​the antenna is maximized in this arrangement, given the maximum mounting height. Thus, the sensitivity of the antenna can be optimized. In this way, the technical parameters of a full-frame antenna can be achieved with a lower mounting height.

[0025] Preferably, the lengths of the sides of the electrical conductor can also be optimized in a similar manner. In an example in the frequency range of ultra-short waves ("Very High Frequency", VHF for short: 20 to 300 MHz (megahertz)), the optimized height of the electrical conductor (i.e., the two sections that protrude from the base plate (outer sections)) is 100 mm (millimeters), and the optimized length (of the section parallel to the surface of the base plate (middle section)) is 300 mm.

[0026] Furthermore, the electrical conductor can be made of copper and / or be mounted on a circuit board.

[0027] The electrical conductor on the circuit board increases the stability of the electrical conductor and simplifies manufacturing. The circuit board can be a PCB (printed circuit board).

[0028] Preferably, the electrical conductor is planar. Planar can mean that the electrical conductor is wider than it is thick, with width and thickness being perpendicular to each other and to a direction of extension (conduction direction) of the electrical conductor. Preferably, the electrical conductor is not a wire. This allows for broadband capability.

[0029] Furthermore, the antenna device may include a load resistor that does not terminate the electrical conductor in a manner consistent with its characteristic impedance.

[0030] The load resistor is preferably connected to one end of the half-frame.

[0031] In an example with an electrical conductor, rectangular in shape, with a height of 80 mm (distance from the base plate) and a length of 240 mm (parallel to the surface of the base plate), the characteristic impedance is approximately 377 ohms (free-space path impedance). A non-characteristic termination can be significantly lower (for example, < 100 ohms) due to a load resistance on such an antenna device.

[0032] In the context of the present disclosure, "correct for characteristic impedance" can mean that the induced voltage components of the electric and magnetic fields become equal in magnitude. In other words, the induced voltage components of the electric and magnetic fields add up at the antenna port, whereas cancellation occurs at the load resistor.

[0033] Because the electrical conductor is not terminated with correct impedance, the antenna has a radiation pattern without a zero point (because the electric and magnetic fields do not completely cancel each other out or add up). Furthermore, this non-impedance termination can result in unidirectional radiation from the antenna (in the direction of the feed point).

[0034] Furthermore, the antenna device may include a signal processing module that is connected to the electrical conductor at one end of the electrical conductor.

[0035] The signal processing module can be part of the electronic components (on the other side of the base plate). The signal processing module can include one or more of the following parts: an antenna port, a low-noise amplifier (LNA), and an analog-to-digital converter.

[0036] Alternatively or additionally, the antenna device may include a signal source module. The signal source module may be part of the electronic components. The signal source module may include one or more of the following parts: an antenna port (possibly the same as that of the signal processing module), a signal amplifier, and a digital-to-analog converter.

[0037] Furthermore, the antenna device can be configured to couple electromagnetic waves in the ultra-short wave range (VHF), i.e., in a range from 20 megahertz, MHz, to 300 MHz.

[0038] Alternatively or additionally, coupling in the UHF (decimeter waves, English: Ultra High Frequency, 0.3 - 3 GHz) and / or SHF (centimeter waves, English: Super high frequency, 3-30 GHz) and / or other frequency ranges is also possible.

[0039] Furthermore, the base plate can be made of aluminum.

[0040] Alternatively, the base plate can be made of a different electrically conductive material. Preferably, the base plate is electrically conductive.

[0041] Furthermore, the installation height can be reduced further by using ferrite material. Ferrite material can be placed within the half-frame(s), thus increasing the self-inductance of the half-frame(s), which would allow for a further reduction in installation height while maintaining similar technical parameters.

[0042] The disclosure also includes a circular group antenna comprising a plurality of antenna devices as disclosed, wherein the respective base plates are a common base plate, and wherein the respective electrical conductors are arranged in a circle.

[0043] The circular array antenna can be a broadband multi-channel direction-finding antenna. Furthermore, the multitude of antenna devices can consist of seven antenna devices.

[0044] Alternatively, a different number of antenna devices is possible.

[0045] The disclosed antenna devices and circular group antennas can be set up and / or used for receiving (directing) and / or transmitting electromagnetic waves / signals.

[0046] The disclosure also includes a manufacturing method for an antenna device, comprising: providing an electrically conductive base plate; and connecting an electrical conductor to the base plate, such that the electrical conductor protrudes from the base plate at both its ends and thus forms a frame with the base plate.

[0047] The described advantages are neither limiting nor exclusive to the respective aspects. An aspect may have further, unmentioned advantages.

[0048] The exemplary embodiments and examples disclosed herein are designed to provide features that will be readily apparent upon reference to the following description in conjunction with the accompanying figures. Exemplary systems, methods, devices, and computer program products are disclosed herein in accordance with various embodiments. It is understood, however, that these embodiments are presented as examples and not as limitations, and it will be obvious to those who have read the present disclosure and possess normal technical knowledge that various modifications to the disclosed embodiments may be made while remaining within the scope of this disclosure.

[0049] Therefore, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Furthermore, the specific sequence and / or hierarchy of steps in the methods disclosed herein are merely exemplary approaches. Based on design preferences, the specific sequence or hierarchy of steps in the disclosed methods or processes may be rearranged while remaining within the scope of this disclosure. Those familiar with the subject matter will therefore understand that the methods and techniques disclosed herein represent various steps or actions in an exemplary sequence, and the present disclosure is not limited to the specific sequence or hierarchy unless expressly stated otherwise.

[0050] It is also understood that any reference to an element here with a label such as "first," "second," etc., does not generally limit the set or order of these elements. Rather, these labels can be used here as a practical means of distinguishing between two or more elements or instances of an element. The reference to a first and a second element therefore does not mean that only two elements can be used or that the first element must in any way precede the second element.

[0051] Furthermore, a person skilled in the art understands that various logic blocks, units, devices, components, and circuits described herein can be implemented in or executed by an integrated circuit (IC), which may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or another programmable logic device, or any combination thereof. The logic blocks, units, and circuits may also include antennas and / or transceivers for communicating with various components within the network or device. A general-purpose processor may be a microprocessor; alternatively, the processor may be any conventional processor, controller, or state machine. A processor may also be implemented as a combination of computing units, e.g.,A combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration for performing the functions described herein. If the functions are implemented in software, they may be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a procedure or algorithm disclosed herein may be implemented as software stored on a computer-readable medium.

[0052] Various modifications of the implementations described in this disclosure are readily apparent to the person skilled in the art, and the general principles defined herein can be applied to other implementations without deviating from the scope of this disclosure. Therefore, the disclosure is not limited to the implementations shown here, but has the broadest possible scope compatible with the new features and principles disclosed herein, as set forth in the claims below.

[0053] The above and other aspects and their implementations are described in more detail in the drawings, descriptions and claims.

[0054] Figure 1 is a schematic representation of an antenna device according to one embodiment of the disclosure.

[0055] Figure 2 is a schematic illustration of an antenna device according to a

[0056] The form of the disclosure.

[0057] Figure 3 is a schematic illustration of a circular array antenna according to a

[0058] The form of the disclosure.

[0059] Figure 4 is an exemplary radiation pattern of an antenna device according to one embodiment of the disclosure.

[0060] Figure 5 is an exemplary radiation pattern for a circular group antenna according to one embodiment of the disclosure.

[0061] Figure 6 is a circular group antenna according to one embodiment of the disclosure.

[0062] Figure 7 is the circular group antenna according to Figure 6. Figure 8 shows a frequency response of a circular group antenna according to an embodiment of the disclosure.

[0063] Figure 9 shows a section of a circular group antenna according to an embodiment of the disclosure.

[0064] Figure 10 shows a manufacturing process of an antenna device according to an embodiment of the disclosure.

[0065] Figure 1 is a schematic representation of an antenna device 10 according to an embodiment of the disclosure. The antenna device 10 comprises a base plate 12 and an electrical conductor 14. The electrical conductor 14 consists of three sections (16, 18, 20): a first vertical section 16, a second vertical section 18 (vertical sections are perpendicular to the surface of the base plate 12 (outer sections)), and a horizontal section 20 (parallel to the surface of the base plate 12 (middle section)).

[0066] The base plate 12 can represent a mass body. The side of the base plate 12 facing the electrical conductor 14 can represent a ground plane and / or an (electromagnetic) mirror surface.

[0067] The base plate 12 is electrically conductive. The base plate 12 is cylindrical. The surface of the base plate 12 facing the electrical conductor 14 is round. The diameter is greater than the length of the horizontal section 20. The thickness of the base plate 12 can be less than the diameter. Alternatively, the thickness can be equal to or greater than the diameter. The base plate can also have a shape other than round, such as rectangular, square, triangular, polygonal, oval, or others.

[0068] The electrical conductor 14 has a rectangular shape (together with part of the surface of the base plate 12). The two vertical sections (16, 18) are shorter than the horizontal section 20, preferably in a ratio of 1:3. The two vertical sections (16, 18) can each be 80 mm long.

[0069] Figure 2 is a schematic representation of an antenna device 10 according to an embodiment of the disclosure. Figure 2 shows a cross-section in the xz-plane compared to Figure 1. In addition to the parts of the antenna device 10 of Figure 1, the antenna device of Figure 2 further comprises electronic elements 22 and an electrical connection 24. The first vertical section 16 of the electrical conductor 14 is electronically connected to the electronic elements 22 via the electrical connection 24. The electronic elements 22 may comprise one or more of the following: (active) electronics, low-noise preamplifiers, calibration antenna switches, etc. Due to the electrically conductive property of the base plate 12, the electrical conductor 14 (as an antenna) is not (or not significantly) affected by (radiation from) the electronic elements 22, except by signals transmitted via the electrical connection 24.

[0070] Figure 3 is a schematic representation of a circular array antenna 26 according to an embodiment of the disclosure. The circular array antenna 26 comprises a plurality (here seven) of antenna devices (10-1 to 10-7). The plurality of antenna devices 10 have a common base plate 12 and each has an electrical conductor 14 (14-1 to 14-7). The electrical conductors 14-1 to 14-7 (or antenna devices 10-1 to 10-7) can be of the same type as the electrical conductors 14 (or antenna devices 10) otherwise disclosed herein. The plurality of electrical conductors 14 is preferably located in an outer region (at the outer edge of the surface) of the base plate 12.

[0071] Alternatively, a different number of antenna devices is also possible, for example three, five, or nine. Furthermore, the different antenna devices do not have to have the same dimensions, as shown in Figure 2; that is, in one embodiment, the antenna devices can have different dimensions.

[0072] Figure 4 is an exemplary radiation pattern of an antenna device 10 according to an embodiment of the disclosure, for example, according to Figure 1 or Figure 2. The radiation pattern has no zero point. This improves direction finding. This can be achieved, for example, by not terminating the antenna device with the correct impedance. The radius of the diagram corresponds to the amplitude in decibels. The angle corresponds to the bearing angle of the antenna device.

[0073] Figure 5 is an exemplary radiation pattern for a circular array antenna 26 according to an embodiment of the disclosure, for example, according to Figure 3. This radiation pattern shows a superposition of seven radiation patterns, each for an antenna device 10 (as in Figure 4) in different orientations. Because the radiation patterns of the individual antenna devices have no zeros (i.e., no sensitivity at an angle Phi), all (seven) antenna devices can contribute to the direction finding. If an antenna had a zero, it could not contribute to the direction finding if the signal came from the direction of the zero.

[0074] The contribution (of each individual antenna element of the circular array antenna 26) to the bearing can include information in phase and / or amplitude. This allows for the use of improved bearing methods, such as PLATH vector matching (compared to the Watson-Watt method). Furthermore, this ensures greater clarity in the bearing evaluation. The radius of the diagram corresponds to the amplitude in decibels. The angle corresponds to the bearing angle of the circular array antenna 26.

[0075] Figures 6 and 7 show an exemplary circular array antenna 26 according to an embodiment of the disclosure, for example, an embodiment according to Figure 3. Figure 7 (side view) shows a view perpendicular to the view of Figure 6 (top view). The exemplary circular array antenna 26 has the following properties:

[0076] The VHF range of approximately 20-300 MHz is set up for use.

[0077] Base plate diameter 12: 1000 mm

[0078] Height of electrical conductor 14: 100 mm

[0079] Frame thickness of electrical conductors 14: 100 mm

[0080] Gap width to neighboring antenna: 40 mm

[0081] Number of antenna elements: 7

[0082] The aforementioned properties are merely examples and do not limit the present invention. A person skilled in the art can adapt the aforementioned properties according to the application without deviating from the fundamental concept of the present disclosure.

[0083] Figure 8 shows the frequency response of a circular array antenna 26 in a 50-ohm system. The x-axis represents frequency in megahertz (MHz). The y-axis represents voltage (voltage standing wave ratio). This demonstrates a further advantage of the design: its applicability over wide frequency ranges.

[0084] In the context of this disclosure, the term "50 Ohm system" refers to an interface via a 50 Ohm port, "in the 50 Ohm impedance system", e.g., connection via a 50 Ohm coaxial cable to other modules in the 50 Ohm impedance system.

[0085] The frequency range of the circular array antenna 26 is scalable. If the diameter of the base plate 12 is increased tenfold (xlO), the frame height and thickness correspond to one tenth of the diameter, and the gap width corresponds to one twenty-fifth of the diameter (i.e., all dimensions are increased tenfold), then the usable bandwidth, approximately 1:15, remains about the same.

[0086] Figure 9 shows a section of a circular array antenna 26, for example according to one or more of Figures 3, 7, and 8. The end of the first vertical section 16 is connected to a resistor 28 (load resistor). The end of the second vertical section 18 is connected to the electrical connection 24 at an antenna port 30. The base plate 12 may have a through-hole at this point. Only the first antenna assembly 10-1 is described in detail here. The other antenna assemblies 10-2 to 10-7 may also include a resistor 28 and / or an electronic connection 24. The antenna port 30 may have an impedance of 100 ohms. The resistor 28 may be less than 100 ohms. A single antenna assembly 10 may also include a resistor 28 and an antenna port 30 in this manner. Resistor 28 and antenna port 30 are also shown in Figures 6 and 7, but not explicitly described.The description of Figure 9 applies equivalently in this respect. Furthermore, for figures in which resistor 28 and antenna port 30 are not shown, it is true that they may nevertheless be present (e.g., Figures 1 and 3). Here, too, the description of Figure 9 applies equivalently. Figure 10 shows a manufacturing process 50 of an antenna device 10 according to an embodiment of the disclosure. The process comprises steps 52 and 54. In step 52, an electrically conductive base plate 12 is provided. In step 54, an electrical conductor 14 is connected to the base plate 12 such that the electrical conductor 14 protrudes from the base plate 12 at both ends and thus forms a frame with the base plate 12.

Claims

Claims 1. An antenna device (10) comprising: an electrically conductive base plate (12); and an electrical conductor (14) which extends from the base plate (12) at both its ends and thus forms a frame with the base plate (12), wherein the electrical conductor (14) is planar.

2. Antenna device (10) according to claim 1, further comprising electronic elements positioned on a side of the base plate (12) facing away from the electrical conductor (14).

3. Antenna device (10) according to one of claims 1 and 2, wherein the antenna device (10) forms a direction-finding antenna.

4. Antenna device (10) according to one of the preceding claims, wherein the electrical conductor (14) comprises three sections (16, 18, 20) which are each at right angles to an adjacent of the three sections (16, 18, 20) and lie together in one plane.

5. Antenna device (10) according to claim 4, wherein two outer sections (16, 18, 20) of the three sections (16, 18, 20) are shorter than a middle section (20) of the three sections (16, 18, 20).

6. Antenna device (10) according to one of claims 4 and 5, wherein each of the three sections (16, 18, 20) is shorter than a wavelength of an electromagnetic wave to be coupled.

7. Antenna device (10) according to one of the preceding claims, wherein the electrical conductor (14) extends orthogonally from the base plate (12) at its ends.

8. Antenna device (10) according to one of the preceding claims, wherein the two ends of the electrical conductor (14) are three times as far apart as the extension distance in which the electrical conductor (14) extends perpendicularly away from the base plate (12) in one direction.

9. Antenna device (10) according to one of the preceding claims, wherein the electrical conductor (14) is made of copper and / or is mounted on a printed circuit board.

10. Antenna device (10) according to one of the preceding claims, further comprising a load resistor (28) which does not terminate the electrical conductor (14) in a manner consistent with the characteristic impedance.

11. Antenna device (10) according to one of the preceding claims, further comprising a signal processing module which is connected to the electrical conductor (14) at one end of the electrical conductor (14).

12. Antenna device (10) according to one of the preceding claims, wherein the antenna device (10) is configured to couple electromagnetic waves in the ultra-short wave range, i.e. in a range from 20 megahertz, MHz, to 300 MHz.

13. Antenna device (10) according to one of the preceding claims, wherein the base plate (12) is made of aluminium.

14. Circular group antenna comprising a plurality of antenna devices (10) according to one of the preceding claims, wherein the respective base plates are a common base plate (12), and wherein the respective electrical conductors (14) are arranged in a circle.

15. Circular group antenna according to claim 14, wherein the plurality of antenna devices (10) are seven antenna devices (10).

16. Manufacturing method (50) of an antenna device (10), comprising: providing (52) an electrically conductive base plate (12); and Connecting (54) an electrical conductor (14) to the base plate (12) such that the electrical conductor (14) protrudes from the base plate (12) at both its ends and thus forms a frame with the base plate (12), wherein the electrical conductor (14) is planar.

Images