CN218975790U - Positioning antenna and positioning system - Google Patents

Abstract

The present disclosure provides a positioning antenna and a positioning system, wherein the positioning antenna includes a base plate; the antenna unit comprises a plurality of square radiating units, wherein the square radiating units are arranged on the upper surface of the bottom plate and distributed in a shape of a Chinese character 'Hui' around the center of the bottom plate; the square radiation unit is a circularly polarized radiation unit; the distance between the adjacent square radiating units is smaller than or equal to the target distance; the target distance is determined based on the wavelength of the highest frequency electromagnetic wave received or emitted by the square radiating element; the control unit is arranged on the lower surface of the bottom plate; the control unit is used for controlling the square radiation unit to emit or receive electromagnetic waves.

Description

Positioning antenna and positioning system

Technical Field

The disclosure relates to the technical field of wireless positioning, in particular to a positioning antenna and a positioning system.

Background

Bluetooth is a short-range radio technology, and a Bluetooth device can send electromagnetic waves to another Bluetooth device, can also receive electromagnetic waves sent by other devices, and utilizes transmission of electromagnetic wave information data, so that communication is realized. In addition to transmitting data, the bluetooth device may also perform positioning. The positioning manner of the bluetooth device widely used generally includes Angle-of-Arrival (AOA) positioning or Angle-of-Departure (AOD) positioning, taking Angle-of-Arrival positioning as an example, the bluetooth device may be provided with a plurality of antennas, each antenna may receive electromagnetic waves emitted by the object to be measured, the bluetooth device may calculate an incident direction of the electromagnetic waves according to a phase when each antenna receives the electromagnetic waves, and calculate a distance between the object to be measured and the bluetooth device according to the incident direction; when electromagnetic waves are transmitted by a bluetooth device, departure angle positioning can be used.

At present, bluetooth devices positioned by using AOA or AOD are generally arrayed by using rod antennas, but the radiation characteristics (such as amplitude, phase and polarization) of an antenna array formed by the rod antennas are severely changed when the pitch angle is close to 0 °, so that positioning accuracy is low.

Disclosure of Invention

The embodiment of the disclosure at least provides a positioning antenna and a positioning system.

In a first aspect, embodiments of the present disclosure provide a positioning antenna, including:

a bottom plate;

the antenna unit comprises a plurality of square radiating units, wherein the square radiating units are arranged on the upper surface of the bottom plate and distributed in a shape of a Chinese character 'Hui' around the center of the bottom plate; the square radiation unit is a circularly polarized radiation unit; the distance between the adjacent square radiating units is smaller than or equal to the target distance; the target distance is determined based on the wavelength of the highest frequency electromagnetic wave received or emitted by the square radiating element;

the control unit is arranged on the lower surface of the bottom plate; the control unit is used for controlling the square radiation unit to emit or receive electromagnetic waves.

In an alternative embodiment, the target distance of the positioning antenna is one half of the wavelength corresponding to the electromagnetic wave with the highest frequency received or emitted by the square radiation unit.

In an alternative embodiment, the spacing between any one of the square radiating elements and its adjacent square radiating element is equal.

In an alternative embodiment, the upper surface of the bottom plate is provided with a first metal plane, and the first metal plane is located at the center of the bottom plate.

In an alternative embodiment, the square radiating element is a square microstrip patch antenna.

In an alternative embodiment, two feeding points are arranged on the square radiating element; the feed point is electrically connected with the control unit; the feed mode of the square radiating unit is bottom feed.

In an alternative embodiment, the edges of the square radiating element are provided with at least one rectangular stub; the rectangular branch is used for adjusting the working frequency of the square radiating element to a target range.

In an alternative embodiment, the number of square radiating elements is 12.

In an alternative embodiment, the square radiating element is provided with a plurality of metallized through holes at the periphery, and the metallized through holes are grounded.

In an alternative embodiment, the bottom plate includes at least three layers of circuit boards; at least one intermediate layer circuit board of the bottom plate is a metal copper foil.

In a second aspect, an embodiment of the present disclosure further provides a positioning system, including a transmitting end device and a receiving end device, where the transmitting end device and/or the receiving end device are the positioning antennas described in the first aspect or any optional implementation manners of the first aspect.

Compared with the traditional rod-shaped antenna, the antenna unit is formed by adopting the patch-shaped square radiating unit, and the gain pattern of the patch-shaped square radiating unit is changed from omni-directional to directional, so that a region with more severe fluctuation of radiation characteristics is not generated; and the square radiating units arranged on the antenna unit are distributed in a shape like a Chinese character 'hui' around the center of the bottom plate, so that the calculation results of the electromagnetic waves in different square radiating units cannot generate great difference, the calculation of the arrival angle or the departure angle is more accurate, and the positioning accuracy is improved.

The foregoing objects, features and advantages of the disclosure will be more readily apparent from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for the embodiments are briefly described below, which are incorporated in and constitute a part of the specification, these drawings showing embodiments consistent with the present disclosure and together with the description serve to illustrate the technical solutions of the present disclosure. It is to be understood that the following drawings illustrate only certain embodiments of the present disclosure and are therefore not to be considered limiting of its scope, for the person of ordinary skill in the art may admit to other equally relevant drawings without inventive effort.

Fig. 1 shows one of the schematic diagrams of a positioning antenna provided by an embodiment of the present disclosure;

FIG. 2 shows a second schematic diagram of a positioning antenna provided by an embodiment of the present disclosure;

fig. 3 is a schematic circuit diagram of a positioning antenna according to an embodiment of the disclosure;

FIG. 4 illustrates a third schematic diagram of a positioning antenna provided by an embodiment of the present disclosure;

fig. 5 shows an amplitude pattern of a positioning antenna provided by an embodiment of the present disclosure;

fig. 6 illustrates an axial ratio pattern of a positioning antenna provided by an embodiment of the present disclosure;

fig. 7 illustrates one of the phase patterns of the positioning antenna provided by embodiments of the present disclosure;

FIG. 8 shows a second phase pattern of a positioning antenna provided by an embodiment of the present disclosure;

fig. 9 shows a schematic diagram of an operating scenario of a positioning antenna provided by an embodiment of the present disclosure.

Illustration of:

the antenna comprises a base plate 10, an antenna unit 20, a square radiation unit 21, a rectangular branch 22, a metallized through hole 23, a coupler 31, a radio frequency switch 32, a Bluetooth module 33, a power supply module 34, a first metal plane 40, a positioning antenna 91 and an object 92 to be measured.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is apparent that the described embodiments are only some embodiments of the present disclosure, but not all embodiments. The components of the embodiments of the present disclosure, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the disclosure, as claimed, but is merely representative of selected embodiments of the disclosure. All other embodiments, which can be made by those skilled in the art based on the embodiments of this disclosure without making any inventive effort, are intended to be within the scope of this disclosure.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

The term "and/or" is used herein to describe only one relationship, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist together, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B, C, and may mean including any one or more elements selected from the group consisting of A, B and C.

In order to solve the technical problem of low positioning accuracy caused by uneven amplitude and phase of a bar-shaped Bluetooth positioning antenna, the embodiment of the disclosure provides a positioning antenna, wherein a patch-shaped square radiation unit is adopted to form an antenna unit; and the square radiating units arranged on the antenna unit are distributed in a shape like a Chinese character 'hui' around the center of the bottom plate, so that the calculation results of the electromagnetic waves in different square radiating units cannot generate great difference, the calculation of the arrival angle or the departure angle is more accurate, and the positioning accuracy is improved.

Referring to fig. 1 and fig. 2, there are respectively one of the schematic diagrams of the positioning antenna provided in the embodiments of the present disclosure, and the second schematic diagram of the positioning antenna provided in the embodiments of the present disclosure. The positioning antenna can adopt arrival angle positioning or departure angle positioning to determine the distance and the relative position between the positioning antenna and an object to be measured, and the positioning antenna comprises a bottom plate 10, an antenna unit 20 and a control unit, wherein:

the antenna unit 20 includes a plurality of square radiating units 21, where the plurality of square radiating units 21 are disposed on the upper surface of the base plate 10 and distributed in a shape of a Chinese character 'hui' around the center of the base plate 10; the square radiation unit 21 is a circularly polarized radiation unit; the distance between the adjacent square radiating units is smaller than or equal to the target distance; the target distance is determined based on the wavelength of the highest frequency electromagnetic wave received or emitted by the square radiating element 21;

the control unit is arranged on the lower surface of the bottom plate 10; the control unit is used for controlling the square radiating element 21 to emit or receive electromagnetic waves.

Among them, the space outside the upper surface of the base plate 10 may be referred to as an upper side of the base plate 10, and the square radiation unit 21 may receive electromagnetic waves from above the base plate 10 or emit electromagnetic waves to above the base plate 10. The square radiation units 21 are similar in size and have similar radiation parameters (such as amplitude and phase), and each square radiation unit 21 is distributed in a shape like a Chinese character 'hui' around the center of the bottom plate 10 to form a central symmetrical antenna unit 20, so that the radiation characteristics of the antenna unit 20 are also central symmetrical, and the arrival angle or departure angle of electromagnetic waves can be calculated conveniently.

Meanwhile, the distance between any square radiating element 21 and the adjacent square radiating element 21 is equal, so that the amplitude and the phase of the antenna element 20 in each detection direction with the same elevation angle are consistent, the amplitude pattern of the antenna element 20 is uniform, and the arrival angle or departure angle is calculated more accurately.

When the positioning antenna is used for positioning calculation, electromagnetic waves emitted by a single electromagnetic wave emitter reach different square radiating units 21 on the positioning antenna in different phases, a plurality of phase differences can be calculated according to the phases of the electromagnetic waves reaching each square radiating unit 21, the direction, namely the arrival angle, of the electromagnetic waves relative to the positioning antenna during emission can be determined according to the phase differences, and the position of an object to be measured relative to the positioning antenna can be calculated according to the arrival angle, the time difference of the electromagnetic waves received by each square radiating unit and the wavelength of the electromagnetic waves.

In a specific implementation process, the distance between adjacent square radiation units 21 is smaller than or equal to a target distance, where the target distance may be determined based on the wavelength of the highest frequency electromagnetic wave received or emitted by the square radiation units 21, and an exemplary target distance may be one half of the wavelength corresponding to the highest frequency electromagnetic wave received or emitted by the square radiation units 21, and if the distance between adjacent square radiation units 21 is greater than the target distance, aliasing may be generated on the electromagnetic wave signals, which affects the calculation accuracy of the arrival angle or departure angle.

In one possible embodiment, the square radiating element 21 may be provided with a first metal plane 40 in a square loop formed on the upper surface of the base plate 10, the first metal plane 40 being a conductor, capable of changing the phase inside the square loop, and the first metal plane 40 being provided to adjust the phase inside the square loop to a desired target area, so as to maintain a certain balance with the phase outside the square loop, and improve the accuracy of the antenna element 20.

The square radiating element 21 can be a microstrip patch antenna, and the microstrip patch antenna has the advantages of small size, low cost, firm structural part, simple process and the like, and can also realize circular polarization work, the electromagnetic wave algorithm under circular polarization is simpler, the calculated amount is low, and the microstrip patch antenna can be conformal with a carrier (namely the bottom plate 10), so that the upper surface of the positioning antenna approaches to a plane.

Fig. 2 shows that the lower surface of the positioning antenna, the square radiating element 21 may be provided with two feeding points, which are electrically connected to the control unit, and the two feeding points may respectively transmit electromagnetic waves of different directions or frequencies. The directions of the electromagnetic waves transmitted by the two feeding points may be perpendicular to each other.

In a specific implementation process, the control unit may include a coupler, a radio frequency switch, a bluetooth module, and a power supply module. Fig. 3 is a schematic circuit diagram of a positioning antenna according to an embodiment of the disclosure. Fig. 3 includes square radiating elements 21, couplers 31, radio frequency switches 32, bluetooth modules 33 and power supply modules 34, each square radiating element 21 is connected with one coupler 31 through a feed point to form a feed mode of bottom feed, each coupler 31 is electrically connected with a radio frequency switch 32, the other end of the radio frequency switch is electrically connected with a bluetooth module 33, at least one square radiating element 21 can be communicated with the bluetooth module 33 through the radio frequency switch 32, and the communication sequence of the radio frequency switch 32 and the bluetooth module 33 can be set according to practical conditions. The coupler 31 may be an H-type coupler, and is capable of converting the transmitted electromagnetic wave into two signals with 90 ° phase difference, so as to calculate the departure angle or arrival angle. The bluetooth module 34 may transmit electromagnetic waves to the square radiating element 21 through the rf switch 32 and the coupler 31, or may receive electromagnetic waves transmitted from the square radiating element 21 through the rf switch 32 and the coupler 31. The power supply module can supply power to each unit of the positioning antenna.

Since there may be a difference in certain radiation characteristics between different square radiation units 21, which may affect the overall radiation characteristics of the antenna unit 20, at least one rectangular branch 22 may be disposed at the edge of the square radiation unit 21, and the rectangular branch 22 may be a conductor, so as to adjust the working frequency (such as phase, amplitude, field width, etc.) of the square radiation unit, thereby adjusting the working frequency of each square radiation unit 21 to a target range, and making the phase of the antenna unit 20 more uniform. Illustratively, as shown in fig. 1, each edge of each square radiating element 21 is provided with a rectangular stub, which is capable of adjusting the operating frequency of the individual square radiating element 21 to a nearly symmetrical state and adjusting the operating frequency of each square radiating element 21 to be within a target range in general.

The number of the square radiating elements 21 may be set according to practical requirements, and the square radiating elements 21 may be kept symmetrically arranged in a zigzag shape, and preferably, the number of the square radiating elements 21 may be set to 8, 12, 16, etc.

Referring to fig. 4, a third schematic diagram of a positioning antenna according to an embodiment of the disclosure is shown. The positioning antenna in fig. 4 comprises 8 square radiating elements 21, the square radiating elements 21 being grouped around a first metal plane 40 (the centre of the base plate 10), the number of square radiating elements 21 being 3 on each side of the base plate.

In order to reduce the mutual influence between the square radiating elements 21, a plurality of metallized through holes 23 may be provided at the periphery of the square radiating elements 21, surrounding the square radiating elements, and grounding the metallized through holes 23, eliminating the interference of electromagnetic waves at the periphery of the metallized through holes 23 with the square radiating elements 21.

The base plate 10 may include at least three layers of circuit boards, and at least one middle layer of the base plate 10 may be a metal copper foil for isolating the upper surface and the lower surface of the base plate 10. Each of the control units may be connected by a radio frequency feeder or a metallized through hole; the bluetooth module 33 gates different square radiating elements 21 to transmit/receive bluetooth signals by controlling the radio frequency switch 32 (each time, only one adjacent square radiating element 21 can be gated, so that the mutual influence between the adjacent square radiating elements 21 can be reduced), the positioning antenna and the object to be measured acquire mutual information through a handshake protocol, and then the bluetooth module 33 calculates the relative position between the positioning antenna and the object to be measured according to the received amplitude/phase information.

The lower surface of the base plate 10 may also be provided with a second metal plane for reducing parasitic radiation of adjacent feed lines.

Referring to fig. 5 and 6, an amplitude pattern of a positioning antenna provided by an embodiment of the present disclosure and an axial ratio pattern of a positioning antenna provided by an embodiment of the present disclosure are shown. In the axial ratio direction diagram of fig. 5, a plurality of equal-amplitude lines are marked, the amplitudes corresponding to the positions on the same equal-amplitude line are the same, and the amplitude values corresponding to the equal-amplitude lines are gradually increased from bottom to top, that is, the amplitude of the positioning antenna is stronger from top to top. In fig. 5, the peak gain of the positioning antenna amplitude is 0.42dB; in fig. 6, the 3dB axis ratio bandwidth is greater than 100 ° and the amplitude is more uniform.

Referring to fig. 7 and 8, one of the phase patterns of the positioning antenna provided by the embodiment of the disclosure and the second phase pattern of the positioning antenna provided by the embodiment of the disclosure are shown respectively. FIG. 7 is a phase pattern at a pitch angle of 70, the shape of the phase pattern being approximately circular with a phase fluctuation of less than 16.5; fig. 8 is a phase pattern at a pitch angle of 60 °, the shape of the phase pattern being closer to a circle than the shape at a pitch angle of 70 °, and the phase fluctuation being less than 9 °. In summary, the phase pattern of the positioning antenna provided by the embodiments of the present disclosure is relatively uniform.

Fig. 9 is a schematic diagram of an operation scenario of a positioning antenna according to an embodiment of the disclosure. The positioning antenna 91 in the figure may be disposed at the top of the center of the scene to position the object 92 to be measured within a detection range (within a broken line) therebelow.

The embodiment of the disclosure also provides a positioning system, which comprises a transmitting end device and a receiving end device, wherein the transmitting end device and/or the receiving end device are/is the positioning antenna.

The basic principles of the present application have been described above in connection with specific embodiments, however, it should be noted that the advantages, benefits, effects, etc. mentioned in the present application are merely examples and not limiting, and these advantages, benefits, effects, etc. are not to be considered as necessarily possessed by the various embodiments of the present application. Furthermore, the specific details disclosed herein are for purposes of illustration and understanding only, and are not intended to be limiting, as the application is not intended to be limited to the details disclosed herein as such.

The block diagrams of the devices, apparatuses, devices, systems referred to in this application are only illustrative examples and are not intended to require or imply that the connections, arrangements, configurations must be made in the manner shown in the block diagrams. As will be appreciated by one of skill in the art, the devices, apparatuses, devices, systems may be connected, arranged, configured in any manner. Words such as "including," "comprising," "having," and the like are words of openness and mean "including but not limited to," and are used interchangeably therewith. The terms "or" and "as used herein refer to and are used interchangeably with the term" and/or "unless the context clearly indicates otherwise. The term "such as" as used herein refers to, and is used interchangeably with, the phrase "such as, but not limited to.

It should also be noted that in the apparatus, devices of the present application, the components may be disassembled and/or assembled. Such decomposition and/or recombination should be considered as equivalent to the present application.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the application to the form disclosed herein. While a number of example aspects and embodiments have been discussed above, a person of ordinary skill in the art will recognize that certain variations, modifications, alterations, additions, and sub-combinations thereof are intended to be included within the scope of the utility model.

Claims (11)

1. A positioning antenna, comprising:

a bottom plate;

the antenna unit comprises a plurality of square radiating units, wherein the square radiating units are arranged on the upper surface of the bottom plate and distributed in a shape of a Chinese character 'Hui' around the center of the bottom plate; the square radiation unit is a circularly polarized radiation unit; the distance between the adjacent square radiating units is smaller than or equal to the target distance; the target distance is determined based on the wavelength of the highest frequency electromagnetic wave received or emitted by the square radiating element;

the control unit is arranged on the lower surface of the bottom plate; the control unit is used for controlling the square radiation unit to emit or receive electromagnetic waves.

2. The positioning antenna of claim 1, wherein the target distance is one half of a wavelength corresponding to an electromagnetic wave of a highest frequency received or emitted by the square radiating element.

3. The positioning antenna of claim 1 wherein the spacing between any one of said square radiating elements and its adjacent square radiating element is equal.

4. The positioning antenna of claim 1 wherein the upper surface of the base plate is provided with a first metal plane, the first metal plane being located at a central location of the base plate.

5. The positioning antenna of claim 1 wherein the square radiating element is a square microstrip patch antenna.

6. The positioning antenna of claim 1, wherein two feed points are provided on the square radiating element; the feed point is electrically connected with the control unit; the feed mode of the square radiating unit is bottom feed.

7. The positioning antenna of claim 1, wherein the edges of the square radiating element are provided with at least one rectangular stub; the rectangular branch is used for adjusting the working frequency of the square radiating element to a target range.

8. The positioning antenna of claim 1 wherein the number of square radiating elements is 12.

9. The positioning antenna of claim 1 wherein a plurality of metallized through holes are provided on the periphery of the square radiating element, the metallized through holes being grounded.

10. The positioning antenna of claim 1 wherein the base plate comprises at least three layers of circuit boards; at least one intermediate layer circuit board of the bottom plate is a metal copper foil.

11. A positioning system comprising a transmitting end device and a receiving end device, the transmitting end device and/or the receiving end device being the positioning antenna of any one of claims 1-10.

Images