A microstrip dipole antenna array for omnidirectional and precise sensing of electromagnetic wave polarization

Abstract

This application belongs to the field of microstrip antenna technology and relates to a microstrip dipole antenna array for omnidirectional and precise sensing of electromagnetic wave polarization, comprising: two antenna units; the antenna units comprising: a patch layer, a dielectric layer, and a coaxial feed structure; the patch layer comprising: two patches, one located at the top and one located at the bottom of the dielectric layer; the two patches are oriented in opposite directions to form a dipole; the inner conductor and the outer conductor of the coaxial feed structure are connected to the two patches, respectively; the dipoles of the two antenna units are oriented perpendicularly to each other, forming a microstrip dipole antenna array to achieve omnidirectional and precise sensing of electromagnetic wave polarization; and further comprising: two other antenna units; the four antenna units are located in four quadrants, and the dipoles of two adjacent antenna units are oriented perpendicularly to each other. The present application can achieve precise sensing of electromagnetic wave polarization in all directions, and is a two-dimensional structure that is easily integrated with the surface of an object.

Description

Technical Field

[0001] The present application relates to the technical field of microstrip antennas, and in particular to a microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization. Background Art

[0002] In the field of wireless communications, polarization is a key characteristic of electromagnetic waves. Properly selecting and controlling the polarization of electromagnetic waves can improve signal transmission quality and reliability, while mitigating the effects of the environment and multipath.

[0003] The polarization of an electromagnetic wave refers to the trajectory of the instantaneous electric field vector at a fixed point in space over time. When the trajectory is a straight line, it is called linear polarization; when the trajectory is a circle, it is called circular polarization; and when the trajectory is an ellipse, it is called elliptical polarization. The polarization of an electromagnetic wave is determined by the two perpendicular electric fields radiated by the antenna. Linearly polarized waves can be divided into vertically polarized waves and horizontally polarized waves. As the names suggest, the electric field of a vertically polarized wave is perpendicular to the ground plane, while the electric field of a horizontally polarized wave is parallel to the ground plane. Matching the polarization of the receiving antenna with that of the incoming wave is crucial. Only when the polarization of the receiving antenna matches that of the incoming wave can the receiving antenna achieve maximum signal strength. Conversely, when the polarization of the receiving antenna completely mismatches that of the incoming wave, the signal strength received by the receiving antenna is minimized, thereby achieving maximum interference suppression. Therefore, polarization control can be an effective means of anti-interference in wireless communications.

[0004] To achieve communication interference resistance by leveraging the polarization characteristics of electromagnetic waves, the first step is to determine the polarization of the interfering signal. Then, based on the polarization of the interfering signal, a completely orthogonal polarization is selected as the polarization of the communication signal, thereby achieving polarization isolation and shielding the interfering signal. Therefore, accurately sensing the polarization of the interfering signal is the most critical and fundamental step in determining the communication polarization selection.

[0005] In existing technologies, most polarization-sensing antennas are three-dimensional spatial structures, which are not easy to integrate with the surface of objects; some two-dimensional microstrip antennas can only sense the polarization of electromagnetic waves in half space. In complex electromagnetic environments, the direction of the incoming waves from the interferer is often uncertain, so it is necessary to sense the polarization of electromagnetic waves in the entire space. Summary of the Invention

[0006] Based on this, it is necessary to provide a microstrip dipole antenna array for omnidirectional and precise perception of electromagnetic wave polarization to address the above technical problems. It can achieve precise perception of electromagnetic wave polarization in all spaces, and it is a two-dimensional structure that is easy to integrate with the surface of objects.

[0007] A microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization, comprising: two antenna units;

[0008] The antenna unit includes: a patch layer, a dielectric layer and a coaxial feeding structure;

[0009] The patch layer includes: two patches respectively arranged on the top and bottom of the dielectric layer; the two patches are in opposite directions to form a dipole; the inner conductor and the outer conductor of the coaxial feeding structure are respectively connected to the two patches;

[0010] The dipoles of the two antenna units are perpendicular to each other, forming a microstrip dipole antenna array to achieve omnidirectional and precise perception of electromagnetic wave polarization.

[0011] In one embodiment, the invention further comprises: two additional antenna units;

[0012] The four antenna units are respectively located in four quadrants, and the directions of the dipoles of two adjacent antenna units are perpendicular to each other.

[0013] In one embodiment, the patch is a rectangular structure, and the length direction of the rectangular structure is the direction of the patch.

[0014] In one embodiment, the dielectric layer has a square structure;

[0015] The length direction of the patch is perpendicular to the edge of the dielectric layer.

[0016] In one embodiment, the width of the patch satisfies:

[0017]

[0018] Where Z0 is the coaxial feed impedance, is the relative dielectric constant of the dielectric layer, W is the width of the patch, and h is the thickness of the dielectric layer.

[0019] In one embodiment, the length of the patch is one quarter of the dielectric wavelength of the center operating frequency of the antenna array.

[0020] In one embodiment, the side length of the dielectric layer is ten times the width of the patch.

[0021] In one embodiment, the coaxial feeding structure is vertically arranged at the center of the dielectric layer.

[0022] In one embodiment, the patch layer further includes: a connecting sheet;

[0023] The inner conductor of the coaxial feeding structure is connected to the patch arranged on the top of the dielectric layer, and the outer conductor of the coaxial feeding structure is connected to the patch arranged on the bottom of the dielectric layer through the connecting piece.

[0024] In one embodiment, the connecting piece is a rectangular structure;

[0025] A long side of the connecting piece coincides with a short side of a patch arranged at the bottom of the dielectric layer.

[0026] The above-mentioned microstrip dipole antenna array for precise omnidirectional perception of electromagnetic wave polarization is designed with two antenna units. The directions of the dipoles of the two antenna units are perpendicular to each other, and there is no floor. It can receive and perceive electromagnetic waves of arbitrary polarization in any direction in the entire space, and realize precise perception of 360° electromagnetic wave polarization in the entire space. At the same time, it is designed as a two-dimensional planar structure, which can be well integrated with the communication polarization control metasurface antenna, thereby realizing the integrated perception and communication functions, and has important application prospects in the field of polarization communication anti-interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of a microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization in one embodiment;

[0028] Figure 2 is a front view schematic diagram of a microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization in another embodiment;

[0029] Figure 3 is a schematic diagram of the reverse side of a microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization in another embodiment;

[0030] Figure 4 Schematic diagram of the front dimensions of an antenna unit in a specific embodiment (taking a vertical dipole as an example);

[0031] Figure 5 Schematic diagram of the reverse dimensions of an antenna unit in a specific embodiment (taking a vertical dipole as an example);

[0032] Figure 6 A diagram showing polarization settings of the incident wave in the simulation software CST in a specific embodiment;

[0033] Figure 7 is a schematic diagram of the reflection coefficient of a microstrip dipole antenna array in a specific embodiment;

[0034] Figure 8 The figure shows the far-field direction simulation diagram of the full-space working characteristics of the microstrip dipole antenna array in a specific embodiment, where (a) is a three-dimensional diagram of a horizontal dipole, (b) is a side view of the horizontal dipole, (c) is a three-dimensional diagram of a vertical dipole, and (d) is a side view of the vertical dipole.

[0035] Reference numerals:

[0036] dielectric layer 1;

[0037] Patch layer 2, first patch 21, second patch 22, connecting patch 23;

[0038] Coaxial feeding structure 3, inner conductor 31, outer conductor 32. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in this application without creative work are within the scope of protection of this application.

[0040] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0041] In addition, the terms "first," "second," and so on, used in this application are for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "multiple groups" means at least two groups, such as two groups, three groups, and so on, unless otherwise specifically defined.

[0042] In this application, unless otherwise specified or limited, the terms "connect," "fix," etc. should be understood in a broad sense. For example, "fix" can mean a fixed connection, a detachable connection, or an integral connection; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean internal communication between two elements or an interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0043] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0044] This application provides a microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization, such as Figure 1As shown, in one embodiment, it includes: two antenna units.

[0045] The antenna unit includes: a dielectric layer, a patch layer and a coaxial feeding structure.

[0046] The dielectric layer is a dielectric substrate made of non-metallic material to carry the patch layer and the coaxial feeding structure.

[0047] The patch layer is made of metal and includes two patches and a connecting patch. The two patches are a first patch and a second patch. The first patch is located on top of the dielectric layer, and the second patch is located on the bottom of the dielectric layer. The two patches serve as antenna arms and are oriented in opposite directions to form a dipole. The connecting patch is a rectangular structure, with one long side of the connecting patch coinciding with one short side of the second patch. In other words, one long side of the connecting patch and one short side of the second patch are collinear and equal, so that the second patch and the connecting patch together form a rectangular structure.

[0048] The coaxial feeding structure includes an inner conductor and an outer conductor; the inner conductor is connected to a first patch arranged on the top of the dielectric layer, and the outer conductor is connected to a second patch arranged on the bottom of the dielectric layer through a connecting piece.

[0049] The directions of the dipoles of the two antenna units are perpendicular to each other, and the orthogonal dipoles form a set of polarization orthogonal bases to form a microstrip dipole antenna array. The superposition of the two mutually orthogonal polarization components forms the electric field of any electromagnetic wave in space, thereby realizing omnidirectional and accurate perception of electromagnetic wave polarization.

[0050] The above-mentioned microstrip dipole antenna array for precise omnidirectional perception of electromagnetic wave polarization is designed with two antenna units. The directions of the dipoles of the two antenna units are perpendicular to each other, and there is no floor. It can receive and perceive electromagnetic waves of arbitrary polarization in any direction in the entire space, and realize precise perception of 360° electromagnetic wave polarization in the entire space. At the same time, it is designed as a two-dimensional planar structure, which can be well integrated with the communication polarization control metasurface antenna, thereby realizing the integrated perception and communication functions, and has important application prospects in the field of polarization communication anti-interference.

[0051] like Figure 2 and Figure 3 As shown, in another embodiment, it further includes: two other antenna units; the four antenna units are respectively located in four quadrants, and the directions of the dipoles of two adjacent antenna units are perpendicular to each other.

[0052] This embodiment can balance the polarization of electromagnetic waves in the entire space, making the polarization in the entire space more uniform, improving the gain and sensitivity of the receiving antenna, and achieving better polarization perception omnidirectionality.

[0053] Preferably, the patch is a rectangular structure, with the length direction of the rectangular structure as the direction of the patch, so as to avoid additional components causing the patch to induce current and be received by the antenna, thereby ensuring the accuracy of polarization perception.

[0054] Further preferably, the dielectric layer has a square structure, and the length direction of the patch is perpendicular to the side of the dielectric layer, so as to decompose the electromagnetic wave into a horizontal component and a vertical component.

[0055] More preferably, the width of the patch (i.e., the arm width) satisfies the following formula to balance the bandwidth and the perception accuracy of the incoming signal, and as the patch width increases, the impedance bandwidth of the antenna becomes wider;

[0056]

[0057] Where Z0 is the coaxial feed impedance (usually 50Ω), is the relative dielectric constant of the dielectric layer, W is the width of the patch, and h is the thickness of the dielectric layer.

[0058] More preferably, the length of the patch (ie, the arm length) determines the resonant frequency of the antenna. Specifically, the length of the patch is one-quarter of the dielectric wavelength (dielectric wavelength) of the center operating frequency of the antenna array. λ0 is the wavelength in vacuum) to accommodate different resonant frequencies and microwave frequency bands.

[0059] More preferably, the side length of the dielectric layer is ten times the width of the patch.

[0060] More preferably, the coaxial feeding structure is vertically arranged at the center of the dielectric layer to achieve the best impedance matching and facilitate integration with other systems.

[0061] like Figure 4 and Figure 5 As shown, in a specific embodiment, the microstrip dipole antenna array includes four antenna units, which are arranged in a 90-degree clockwise rotation; the dielectric layer of the antenna unit is a square structure with a side length of 20 mm and is made of F4B with a dielectric constant of 2.65; the first patch of the patch layer in the antenna unit has a length of 5.5 mm and a width of 2 mm, the second patch has a length of 5.5 mm and a width of 2 mm, and the connecting patch has a length of 2 mm and a width of 1.15 mm; the coaxial feeding structure is provided at the center of the dielectric layer, specifically using the existing technology; the length of a dipole is 11 mm.

[0062] For the above embodiment, the existing technology is used to set an incident electromagnetic wave with arbitrary polarization, and the sensed polarization angle is calculated based on the amplitude and phase received by the antenna for simulation verification.

[0063] like Figure 6As shown in the figure, the plane wave excitation source in the electromagnetic simulation software CST is used to complete the setting of incident electromagnetic waves of arbitrary polarization through different options and parameter adjustments.

[0064] Polarization perception is achieved through polarization decomposition. The electric field E of the incident electromagnetic wave of arbitrary polarization in space i can be decomposed on a set of orthogonal bases:

[0065]

[0066] Where, E i is the electric field of the incident electromagnetic wave with arbitrary polarization in space, is the component of the incident wave electric field in the vertical direction, is the component of the incident wave electric field in the horizontal direction, is the unit wave vector in the vertical direction, is the unit wave vector in the horizontal direction;

[0067] Then the instantaneous equation is:

[0068]

[0069] Where E(z,t) is the general time-domain expression for an arbitrary electromagnetic wave propagating in the z direction, w is the angular frequency, t is the time variable, k is the phase constant or propagation constant, z represents the direction of electromagnetic wave propagation, and θ is the phase difference between the two components.

[0070] The orthogonally placed dipole antennas extract the electric field information in the orthogonal directions through the induced current. By analyzing and calculating the vertical component information and the horizontal component information, the polarization of the incident electromagnetic wave can be obtained.

[0071] When θ=0° or ±180°, it is linear polarization. The polarization angle of linear polarization is:

[0072]

[0073] When θ=±90° and When , it is circular polarization.

[0074] In other cases, it is elliptical polarization.

[0075] For linear polarization, the polarization angle can be calculated based on the amplitudes sensed by two orthogonal dipole antennas. The difference in amplitudes sensed by the two orthogonal dipole antennas is:

[0076]

[0077] Where, is the electric field sensed by the vertically placed dipole microstrip antenna, is the electric field sensed by a horizontally placed dipole microstrip antenna.

[0078] Therefore, we have:

[0079]

[0080] For linear polarization with different polarization angles, the perception conditions (parameters and perception results) of the incident electromagnetic wave are shown in Table 1.

[0081] Table 1: Perception of linearly polarized incident electromagnetic waves at different polarization angles

[0082]

[0083]

[0084] Table 1 shows that while there is a certain error between the perceived polarization angle and the polarization angle set by the simulation software, the error fluctuation is very small. After subsequent unified compensation and correction, the perceived polarization angle error for linear polarization is less than 0.02°, demonstrating high perception accuracy.

[0085] For circular polarization and elliptical polarization, the perception conditions (parameters and perception results) of different incident electromagnetic waves are shown in Table 2.

[0086] Table 2: Perception of incident electromagnetic waves with (elliptical) polarization of different parameters

[0087]

[0088] It can be seen from Table 2 that for circular polarization, the microstrip dipole antenna array designed in this application can achieve accurate perception with zero error; for elliptical polarization, the error is also kept in a very low range.

[0089] The above results confirm the ability of the microstrip dipole antenna array designed in this application to accurately sense electromagnetic waves of arbitrary polarization.

[0090] like Figure 7 The figure shows the reflection coefficient of the microstrip dipole antenna array. Here, a reflection coefficient of -6dB is used as the working bandwidth of the antenna for sensing electromagnetic wave polarization. The maximum radiation direction of the antenna is located in the bilateral radiation perpendicular to the dielectric layer, thus increasing the flexibility of electromagnetic wave polarization perception to a certain extent.

[0091] like Figure 8 The far-field direction simulation diagram of the full-space working characteristics of the microstrip dipole antenna array shown in the figure shows that the antenna array has a good perception capability for electromagnetic waves incident from all directions in space.

[0092] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization, characterized in that: include: Two antenna units; The antenna unit includes: a patch layer, a dielectric layer and a coaxial feeding structure; The patch layer includes: two patches respectively arranged on the top and bottom of the dielectric layer; the two patches are in opposite directions to form a dipole; the inner conductor and the outer conductor of the coaxial feeding structure are respectively connected to the two patches; The dipoles of the two antenna units are perpendicular to each other, forming a microstrip dipole antenna array to achieve omnidirectional and precise perception of electromagnetic wave polarization.

2. The microstrip dipole antenna array for omnidirectional precise sensing of electromagnetic wave polarization according to claim 1, characterized in that: Also includes: two additional antenna units; The four antenna units are respectively located in four quadrants, and the directions of the dipoles of two adjacent antenna units are perpendicular to each other.

3. A microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization according to claim 1 or 2, characterized in that: The patch is a rectangular structure, and the length direction of the rectangular structure is the direction of the patch.

4. The microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization according to claim 3, characterized in that: The dielectric layer has a square structure; The length direction of the patch is perpendicular to the edge of the dielectric layer.

5. The microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization according to claim 4, characterized in that: The width of the patch satisfies: Where Z0 is the coaxial feed impedance, is the relative dielectric constant of the dielectric layer, W is the width of the patch, and h is the thickness of the dielectric layer.

6. The microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization according to claim 5, characterized in that: The length of the patch is one quarter of the dielectric wavelength of the central operating frequency of the antenna array.

7. The microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization according to claim 6, characterized in that: The side length of the dielectric layer is ten times the width of the patch.

8. A microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization according to claim 1 or 2, characterized in that: The coaxial feeding structure is vertically arranged at the center of the dielectric layer.

9. A microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization according to claim 1 or 2, characterized in that: The patch layer further includes: a connecting sheet; The inner conductor of the coaxial feeding structure is connected to the patch arranged on the top of the dielectric layer, and the outer conductor of the coaxial feeding structure is connected to the patch arranged on the bottom of the dielectric layer through the connecting piece.

10. The microstrip dipole antenna array for accurate omnidirectional sensing of electromagnetic wave polarization according to claim 9, characterized in that: The connecting piece is a rectangular structure; A long side of the connecting piece coincides with a short side of a patch arranged at the bottom of the dielectric layer.

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