CN115810896A - Microstrip Antennas and Positioning Systems - Google Patents

Abstract

The invention discloses a microstrip antenna and a positioning system. A microstrip antenna comprising: the antenna comprises a dielectric substrate, and a radiation layer and a grounding layer which are respectively positioned on two sides of the dielectric substrate; the radiating layer comprises at least two identical radiating units and a feed unit, the radiating units are rectangular metal sheets with round hollowed parts in the middle, the at least two radiating units are coupled and fed through the feed unit, and each radiating unit is connected with the adjacent radiating unit through a short-circuit branch; the grounding layer is a metal sheet covering one side of the medium substrate; the feed unit is connected with a feed port of the microstrip antenna. According to the technical scheme of the embodiment of the invention, the provided microstrip antenna has the advantages of higher bandwidth, smaller volume and high cross polarization, and can meet the use requirement of a positioning system.

Description

Microstrip Antennas and Positioning Systems

technical field

Embodiments of the present invention relate to antenna technology, and in particular to a microstrip antenna and a positioning system.

Background technique

As the carrier of transmitting and receiving information in the wireless communication system, the antenna is one of the key components in the wireless communication system, and its performance directly affects the technical indicators of the wireless communication system. For positioning systems based on Angle-of-Arrival (AOA), not only have high requirements for antenna mechanical properties, circuit parameters, and amplitude patterns, but also have high requirements for the isotropic consistency of phase patterns. higher requirements.

Compared with other antennas, microstrip antennas have some unique advantages, such as light weight, low profile, easy integration, convenient assembly, and fewer solder joints. However, ordinary microstrip antennas are resonant antennas with high Q values and narrow frequency bands. The shortcoming is that its relative bandwidth can only reach 0.6~3% at the widest, and it is applied to the antenna of the communication system. The phase consistency of each array element of the array antenna has not been considered for the time being, and it cannot be applied to the system based on AOA positioning, which limits The application of microstrip antenna in integrated antenna for communication and positioning.

Contents of the invention

The invention provides a microstrip antenna and a positioning system for providing an antenna with high bandwidth, small volume and high cross polarization.

In a first aspect, an embodiment of the present invention provides a microstrip antenna, including:

a dielectric substrate and a radiation layer and a ground layer respectively located on both sides of the dielectric substrate;

The radiating layer includes at least two identical radiating units and a feeding unit. The radiating unit is a rectangular metal sheet with a circular hollow in the middle. At least two radiating units are coupled and fed through the feeding unit. Each radiating unit is connected to the Adjacent radiating element connections;

The ground layer is a metal sheet covering one side of the dielectric substrate;

The feed unit is connected with the feed port of the microstrip antenna.

In a possible implementation manner of the first aspect, the radiation current length of the radiation unit is designed based on half of the wavelength corresponding to the working frequency band of the microstrip antenna.

In a possible implementation manner of the first aspect, there are an even number of radiation units, and at least two radiation units are arranged in a rectangle.

In a possible implementation manner of the first aspect, there are four radiation units, and the four radiation units are arranged in a square.

In a possible implementation manner of the first aspect, the feeding unit is located at the center of at least two identical radiating units.

In a possible implementation manner of the first aspect, the feeding unit is a rectangular metal sheet located at the center of at least two identical radiating units.

In a possible implementation manner of the first aspect, the direction of the short-circuit stub is perpendicular to the direction of the feed unit.

In a possible implementation manner of the first aspect, the size of the metal sheet constituting the ground layer is less than or equal to half of the wavelength corresponding to the working frequency band of the microstrip antenna.

In a possible implementation of the first aspect, the dielectric substrate is connected to an SMA connector on the side of the ground layer, the inner conductor of the SMA connector is used as a feed port to pass through the dielectric substrate and connected to the feed unit, and the outer conductor of the SMA connector The conductor is connected to the ground plane.

In the second aspect, an embodiment of the present invention provides a positioning system. The positioning system includes a baseband processing unit, a radio frequency processing unit, and an antenna. The antenna is a microstrip antenna in any possible implementation of the first aspect.

The microstrip antenna and positioning system provided by the embodiments of the present invention include a dielectric substrate and a radiation layer and a ground layer respectively located on both sides of the dielectric substrate, wherein the radiation layer includes at least two identical radiating units and a feeding unit, and the radiating unit It is a rectangular metal sheet with a circular hollow in the middle. At least two radiating units are coupled and fed by the feeding unit. Each radiating unit is connected to the adjacent radiating unit through a short-circuit branch. The ground layer is a metal sheet covering one side of the dielectric substrate. The feed unit is connected to the feed port of the microstrip antenna. By setting a plurality of rectangular radiation units with circular hollows and short-circuit branches connecting the radiation units, the microstrip antenna provided by the embodiment of the present invention has a higher bandwidth and a smaller volume. Small and highly cross-polarized, it can meet the needs of positioning systems.

Description of drawings

FIG. 1 is a top view of a microstrip antenna provided by an embodiment of the present invention;

FIG. 2 is a side view of a microstrip antenna provided by an embodiment of the present invention;

Fig. 3 is the S parameter schematic diagram of the microstrip antenna based on above-mentioned concrete example;

Fig. 4 is the horizontal direction gain schematic diagram of the microstrip antenna based on above-mentioned concrete example;

FIG. 5 is a schematic diagram of the vertical gain of the microstrip antenna based on the above specific example.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, only some structures related to the present invention are shown in the drawings but not all structures.

Figure 1 and Figure 2 are schematic structural diagrams of a microstrip antenna provided by an embodiment of the present invention, wherein Figure 1 is a top view of a microstrip antenna provided by an embodiment of the present invention, and Figure 2 is a top view of a microstrip antenna provided by an embodiment of the present invention. Side view of a microstrip antenna.

As shown in FIG. 1 and FIG. 2 , the microstrip antenna provided in this embodiment includes a dielectric substrate 11 and a radiation layer 12 and a ground layer 13 respectively located on both sides of the dielectric substrate 11 .

The radiation layer 11 includes at least two identical radiation units 14 and a feed unit 15, the radiation unit 14 is a rectangular metal sheet with a circular hollow in the middle, at least two radiation units 14 are coupled and fed through the feed unit 15, each The radiation unit 14 is connected to the adjacent radiation unit 14 through the short-circuit branch 16; the ground layer 13 is a metal sheet covering one side of the dielectric substrate; the feed unit 15 is connected to the feed port of the microstrip antenna. The dielectric substrate 11 can be a dielectric substrate with any dielectric constant, and the radiation unit 14 , the feed unit 15 , the short-circuit stub 16 and the ground layer 13 can all be copper clad on the dielectric substrate 11 . In this embodiment, four identical radiating units 14 are taken as an example for illustration, but the microstrip antenna provided by the present invention is not limited thereto.

The microstrip antenna provided by the embodiment of the present invention is composed of a dielectric substrate 11, a radiation layer 12, and a ground layer 13. This is the basic structure of a microstrip antenna. The radiation layer 12 is used as a radiator of electromagnetic waves, and the ground layer 13 is used as a metal reflector and grounded. , together with the dielectric substrate 11 and the radiation unit 14 in the radiation layer 12 , realize the radiation of electromagnetic waves.

The radiation unit 14 in the radiation layer 12 is used for transmitting and receiving electromagnetic waves. The traditional microstrip antenna has only one radiation unit, but in this embodiment, the radiation layer 12 includes at least two radiation units 14, at least two radiation units 14 It can effectively improve the bandwidth of the microstrip antenna.

The size of the metal sheet constituting the ground layer 13 may be less than or equal to half of the wavelength corresponding to the working frequency band of the microstrip antenna.

There is a certain gap between at least two radiating units 14 and the feeding unit 15 , at least two radiating units 14 are coupled and fed through the feeding unit 15 , and the feeding unit 15 is connected to the feeding port of the microstrip antenna. The feed port may be disposed on one side of the ground layer 13 and connected to the feed unit 15 through the dielectric substrate 11 . In this way, at least two radiating elements 14 are equivalent to multiple parasitic elements of a microstrip antenna.

The radiating unit 14 is a rectangular metal sheet, which is also a basic radiating unit structure of a microstrip antenna, but in this embodiment, a circular hollow is opened in the middle of each radiating unit 14 . In the traditional microstrip antenna structure, the size of the rectangular radiating unit is designed based on half of the wavelength corresponding to the working frequency band of the microstrip antenna. The size of the radiation unit refers to the size of the side length of the radiation unit. That is to say, theoretically, the size of the radiating unit of the microstrip antenna is one-half of the wavelength corresponding to the working frequency band, and then the actual structure of the microstrip antenna is optimized and debugged based on the above size. This places a limit on the minimum size of the radiating element of the microstrip antenna. In this embodiment, a circular hollow is opened in the middle of each radiating unit 14, which can change the distribution of current on the radiating unit 14, so that the radiating unit 14 becomes a ring-like structure, and the effective size of the radiating unit 14 is no longer Determined according to the side length of the radiating unit 14, but according to the current length of the radiating unit 14 around the hollow hole, which can effectively reduce the size of the radiating unit 14, and further effectively reduce the size of the microstrip antenna. The radiation current length of the radiation unit 14 can be designed based on half of the wavelength corresponding to the working frequency band of the microstrip antenna, that is, the equivalent radiation electrical length on the radiation unit 14 is about half of the wavelength corresponding to the working frequency band of the microstrip antenna. When the diameter of the circular hollow in the radiating unit 14 is larger, the equivalent electrical length on the remaining radiating unit 14 is also longer, so the intensity of the radiating unit on the smaller sized radiating unit 14 can meet the requirements corresponding to the working frequency band of the microstrip antenna. One-half of the wavelength requirement.

The size of the circular hollow in each radiation unit 14 can be set according to actual needs. The larger the radius of the circular hollow, the smaller the size of the radiation unit 14 can be set, but the radiation performance of the radiation unit 14 is also weaker correspondingly. The actual use needs to set the radius of the circular hollow.

The radiating unit 14 shown in the figure is a rectangle with cut corners, but the microstrip antenna provided by the embodiment of the present invention is not limited thereto, and the radiating unit 14 may be a rectangle.

After at least two radiating elements 14 are configured for the microstrip antenna, and each radiating element 14 is set as a rectangular metal sheet with a circular hollow, on the one hand, a plurality of radiating elements can improve the bandwidth of the microstrip antenna, on the other hand After setting the circular hollow, the arrangement of multiple radiation units will not increase the overall size of the microstrip antenna, so that the overall size of the microstrip antenna is within a controllable range. The effective control of the overall size of the microstrip antenna is also conducive to improving the isolation between the microstrip antenna and other devices.

Each radiating element 14 is connected to an adjacent radiating element 14 via a short-circuit stub 16 . The short-circuit stub 16 is a metal sheet for connecting adjacent radiation units 14 . Each radiating unit 14 only needs to be connected to one adjacent radiating unit 14 through a short-circuit stub 16 . For example, in the structure of four radiation units 14 shown in FIG. 1 , every two radiation units 14 are connected by a short-circuit stub 16 . After at least two radiating units 14 are arranged, there may be an influence between adjacent radiating units 14 , and the setting of the short-circuit stub 16 is to improve cross-polarization performance.

There are four radiating units 14 shown in the figure, and the four radiating units 14 are arranged in a square shape, so that the entire microstrip antenna has the most compact structure and the smallest size. However, the microstrip antenna provided by the embodiment of the present invention is not limited thereto. Generally, in order to facilitate the arrangement and feeding of the radiating units 14, the radiating units 14 can be an even number, and each radiating unit 14 is arranged in a rectangle, so that each Radiation units 14 are compactly arranged. In order to facilitate the power feeding unit 15 to couple and feed multiple radiating units 14 , the feeding unit 15 may be located at the center of the radiating units 14 , so that the power feeding unit 15 feeds each radiating unit 14 at the same magnitude.

The feeding unit 15 shown in FIG. 1 is a rectangular metal sheet. The purpose of setting the feeding unit 15 in a rectangular shape is to make the coupling and feeding strength of the feeding unit 15 to the four radiation units 14 the same. The feeding unit 15 can also be in other shapes, as long as it can couple and feed power to multiple radiation units 14, and the feeding strength is the same.

The direction of the short-circuit stub 16 may be perpendicular to the direction of the feed unit 15 , and the horizontal currents of adjacent radiation units 14 may cancel each other through the short-circuit stub, thereby providing cross-polarization performance. As shown in FIG. 1 , the short-circuit stub 16 is along the horizontal direction, and the feed unit 15 is along the vertical direction.

The feed port of the microstrip antenna provided in this embodiment may adopt any connection form, for example, the feed unit 15 is directly connected to the radio frequency processing unit. In order to facilitate the production and assembly of the microstrip antenna provided in this embodiment, a radio frequency connector may be used as a feeding port. For example, an SMA connector can be connected on the side where the dielectric substrate 11 is located at the ground layer 13, the inner conductor of the SMA connector is used as a feed port to pass through the dielectric substrate 11 and connected to the feed unit 15, and the outer conductor of the SMA connector is connected to the ground layer 13 . As a radio frequency coaxial connector, SMA can easily connect the antenna and the radio frequency processing unit through a coaxial cable, and has a small size. Certainly, the feeding port of the microstrip antenna provided in the embodiment of the present invention may also be connected by other forms of radio frequency connectors.

The microstrip antenna provided by the embodiment of the present invention includes a dielectric substrate and a radiation layer and a ground layer respectively located on both sides of the dielectric substrate, wherein the radiation layer includes at least two identical radiating elements and a feeding element, and the radiating element has a A circular hollow rectangular metal sheet, at least two radiating units are coupled and fed through the feeding unit, each radiating unit is connected to the adjacent radiating unit through a short-circuit branch, the ground layer is a metal sheet covering one side of the dielectric substrate, and the feeding unit Connected to the feeding port of the microstrip antenna, by setting a plurality of rectangular radiating units with circular hollows and short-circuit branches connecting the radiating units, the microstrip antenna provided by the embodiment of the present invention has a higher bandwidth and a smaller volume, and The cross polarization is high, which can meet the needs of the positioning system.

In a specific example of the microstrip antenna provided by the embodiment of the present invention, the specific structure of the microstrip antenna is shown in Figure 1 and Figure 2, wherein the node constant of the dielectric substrate 11 is 3.38, and the thickness of the dielectric substrate is 3.25mm , the metal plate constituting the ground layer 13 has a length of 30 mm and a width of 30 mm. The length of each radiating unit 14 is 9.985 mm, the width is 8.7 mm, and the cut corner of the rectangle is 1 mm. The radius of the circular hollow in the radiation unit 14 is 3.3 mm. The radiation unit 15 has a length of 12.2mm and a width of 2.548mm. The short-circuit stub 16 has a length of 2.5 mm and a width of 1.1 mm.

FIG. 3 is a schematic diagram of S parameters of the microstrip antenna based on the above specific example, and the curve in the figure is the S11 curve of the microstrip antenna based on the above specific example. It can be seen from Figure 3 that the frequency bandwidth not greater than -10dB is 4800MHz-5300MHz, the absolute bandwidth reaches 500MHz, and the relative bandwidth relative to the center frequency point reaches 10%, which is much higher than the relative bandwidth of about 3% of ordinary single-layer microstrip antennas. bandwidth.

Fig. 4 is the horizontal direction gain schematic diagram of the microstrip antenna based on above-mentioned concrete example, and wherein curve 41 is the direction gain curve of radiation unit, and curve 42 is the direction gain curve perpendicular to the polarization direction of radiation unit, as can be seen from the figure, The horizontal gain reaches 6.75dBi, the 3dB lobe width is 85.9 degrees, the antenna axial cross-polarization ratio is greater than 57dB, and the cross-polarization ratio within the range of ±60° is greater than 50dB.

FIG. 5 is a schematic diagram of the vertical gain of the microstrip antenna based on the above specific example. It can be seen from the figure that the vertical gain reaches 6.75dBi, and the 3dB lobe width is 88.2 degrees.

An embodiment of the present invention also provides a positioning system, which includes a baseband processing unit, a radio frequency processing unit, and an antenna, wherein the antenna is the microstrip antenna in any of the above embodiments. The positioning system may be an AOA-based positioning system.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention, and the present invention The scope is determined by the scope of the appended claims.

Claims (10)

1. A microstrip antenna, characterized in that, comprising: a dielectric substrate and a radiation layer and a ground layer respectively located on both sides of the dielectric substrate; The radiating layer includes at least two identical radiating units and a feeding unit, the radiating unit is a rectangular metal sheet with a circular hollow in the middle, and the at least two radiating units are coupled and fed through the feeding unit, Each radiating unit is connected to an adjacent radiating unit through a short-circuit stub; The ground layer is a metal sheet covering one side of the dielectric substrate; The feeding unit is connected to the feeding port of the microstrip antenna. 2. The microstrip antenna according to claim 1, wherein the radiation current length of the radiating unit is designed based on half of the wavelength corresponding to the working frequency band of the microstrip antenna. 3 . The microstrip antenna according to claim 1 , wherein there are an even number of the radiating elements, and the at least two radiating elements are arranged in a rectangle. 4 . 4. The microstrip antenna according to claim 3, characterized in that there are four radiation units, and the four radiation units are arranged in a square. 5. The microstrip antenna according to claim 1, wherein the feeding unit is located at the center of the at least two identical radiating units. 6. The microstrip antenna according to claim 5, wherein the feeding unit is a rectangular metal sheet located at the center of the at least two identical radiating units. 7. The microstrip antenna according to claim 1, wherein the direction of the short-circuit stub is perpendicular to the direction of the feeding unit. 8. The microstrip antenna according to any one of claims 1-7, characterized in that the size of the metal sheet constituting the ground layer is less than or equal to half of the wavelength corresponding to the working frequency band of the microstrip antenna. 9. The microstrip antenna according to any one of claims 1 to 7, wherein the dielectric substrate is connected to an SMA connector on one side of the ground layer, and the inner conductor of the SMA connector is used as the The feed port is connected to the feed unit through the dielectric substrate, and the outer conductor of the SMA connector is connected to the ground layer. 10. A positioning system, characterized in that the positioning system comprises a baseband processing unit, a radio frequency processing unit and an antenna, and the antenna is the microstrip antenna according to any one of claims 1-9.

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