Polarization converter and communication device
By using a combination structure of an open-ended resonant element formed by elliptical and strip metal sheets, a dielectric layer, and a reflective layer, the problems of insufficient miniaturization and excessive weight of traditional polarization converters are solved, realizing a highly efficient, miniaturized, and lightweight polarization converter suitable for modern communication equipment.
Patent Information
- Application Number
- CN202423011662.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-06
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2034-12-06
AI Technical Summary
The traditional polarization converter unit structure is not miniaturized enough and the device is too heavy to meet the miniaturization requirements of modern communication equipment.
The combined structure of an open resonant element formed by an elliptical metal sheet and a strip metal sheet, a dielectric layer and a reflective layer utilizes their anisotropic characteristics to achieve polarization conversion, and the resonant element is small in size and light in weight.
The miniaturization and lightweight of the polarization converter are achieved, and the polarization conversion efficiency is improved. In particular, the circular polarization conversion efficiency in the frequency range of 5.3GHz-13.0GHz reaches more than 95%, the phase difference fluctuates in the range of 0.83-1.05, and the frequency selectivity is good.
Smart Images
Figure CN223451198U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of communication, in particular to a polarization converter and a communication device. BACKGROUND
[0002] Polarization is one of the important characteristics of electromagnetic waves. In various electromagnetic applications such as wireless communication, antenna design, radar technology and radar stealth, it is essential to manipulate the polarization state of electromagnetic waves. Traditional polarization control methods usually use the birefringence effect and optical activity of natural materials to achieve this, which results in insufficient miniaturization of the polarization converter unit structure and excessive weight of the device. CONTENT OF THE UTILITY MODEL
[0003] In order to solve the problems in the prior art, the present application provides a polarization converter and a communication device, which are beneficial to the miniaturization of the resonant converter.
[0004] The present application provides a polarization converter, which comprises at least one polarization conversion unit.
[0005] The polarization conversion unit comprises a resonant element, a dielectric layer and a reflective layer arranged in sequence along a first direction; the first direction is perpendicular to the plane where the resonant element is located.
[0006] The resonant element comprises an elliptical metal sheet and a strip-shaped metal sheet; two ends of the short axis of the elliptical metal sheet are respectively provided with openings; two ends of the strip-shaped metal sheet are respectively connected to two ends of the long axis of the elliptical metal sheet.
[0007] In an embodiment, the length of the polarization conversion unit along a second direction is 15±0.1mm, and the length of the polarization conversion unit along a third direction is 13.6±0.1mm; the first direction, the second direction and the third direction are perpendicular to each other.
[0008] In an embodiment, the long axis of the elliptical metal sheet is 12.73±0.1mm, the short axis is 11.35±0.1mm, the thickness is 0.035±0.1mm, and the diagonal distance of the two openings is 11.18±0.1mm.
[0009] In an embodiment, the dielectric layer comprises a first dielectric layer and a second dielectric layer arranged in sequence along the first direction; the dielectric constant of the first dielectric layer is 2.2±0.1, and the dielectric constant of the second dielectric layer is 1.05±1.
[0010] In an embodiment, the material of the first dielectric layer comprises one of polyimide, silicon dioxide and epoxy resin.
[0011] In an embodiment, the material of the second dielectric layer comprises foam.
[0012] In one embodiment, the first dielectric layer has a thickness of 0.51±0.1 mm.
[0013] In one embodiment, the second dielectric layer has a thickness of 7±0.1 mm.
[0014] In one embodiment, the plurality of polarization conversion units are arranged in an array on a plane.
[0015] The present application also provides a communication device comprising the polarization converter described above.
[0016] The present application realizes polarization conversion through the open resonant element formed by the elliptical metal sheet and the strip-shaped metal sheet, the dielectric layer and the reflective layer, and the resonant element has small size and light weight, which is conducive to the miniaturization of the resonant converter. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 FIG. 1 is a structural diagram of a polarization converter according to one embodiment of the present application.
[0018] Figure 2 FIG. 2 is a structural diagram of a resonant element according to one embodiment of the present application.
[0019] Figure 3 FIG. 3 is a structural diagram of a polarization converter according to another embodiment of the present application.
[0020] Figure 4 FIG. 4 is a reflection coefficient waveform diagram of a left-handed circularly polarized wave according to one embodiment of the present application.
[0021] Figure 5 FIG. 5 is a circular polarization conversion efficiency waveform diagram of a left-handed circularly polarized wave according to one embodiment of the present application.
[0022] Figure 6 FIG. 6 is a reflection phase waveform diagram of an orthogonal linearly polarized wave according to one embodiment of the present application.
[0023] Figure 7 FIG. 7 is a reflection coefficient waveform diagram of an orthogonal linearly polarized wave according to one embodiment of the present application.
[0024] Figure 8 FIG. 8 is a phase difference waveform diagram of an orthogonal linearly polarized wave according to one embodiment of the present application.
[0025] Figure 9 FIG. 9 is a schematic diagram of the electric field energy density of a polarization converter according to one embodiment of the present application.
[0026] Figure 10 FIG. 10 is a schematic diagram of the surface current distribution of a polarization converter according to one embodiment of the present application.
[0027] MAIN ELEMENT SYMBOL EXPLANATION
[0028] Polarization converter 10
[0029] resonant element 110
[0030] dielectric layer 120
[0031] reflective layer 130
[0032] elliptical metal piece 111
[0033] strip-shaped metal piece 112
[0034] first dielectric layer 121
[0035] second dielectric layer 122
[0036] polarization conversion unit 100
[0037] opening 113
[0038] strip-shaped metal piece 111a
[0039] first direction L1
[0040] second direction L2
[0041] third direction L3
[0042] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION
[0043] The following description will refer to the accompanying drawings, in which the example embodiments of the application are shown. However, the application can be implemented in many different forms and should not be construed as limited to the example embodiments set forth herein. These example embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. Like reference numerals refer to like or similar components throughout.
[0044] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, to the extent that the terms "including", "includes", "having", "has", "a", "an", "one" or "said one" are used in this specification and / or claims, such terms are considered as excluding only the presence of one or more other features, regions, integers, steps, operations, elements, and / or groups thereof.
[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an overly literal sense unless expressly so defined herein.
[0046] The following description will be made with reference to the accompanying drawings. It should be noted that the components depicted in the drawings are not necessarily shown to scale; rather, the same or similar components will be assigned the same or similar reference numerals to indicate or similar technical terms.
[0047] Referring to Figure 1 and Figure 2 The present application proposes a polarization converter 10, which comprises one or more polarization conversion units 100. Figure 1 Take an example that the polarization converter 10 comprises one polarization conversion unit 100.
[0048] The polarization conversion unit 100 comprises a resonant element 110, a dielectric layer 120 and a reflective layer 130 arranged in sequence along a first direction L1. The first direction L1 is perpendicular to the plane where the resonant element 110 is located. The resonant element 110 comprises an elliptical metal sheet 111 and a strip metal sheet 112; two ends of the short axis of the elliptical metal sheet 111 are respectively provided with openings 113; two ends of the strip metal sheet 112 are respectively connected to two ends of the long axis of the elliptical metal sheet 111. In this embodiment, the long axis of the elliptical metal sheet 111 is the longest line segment obtained by connecting two points on the elliptical metal sheet 111. The short axis of the elliptical metal sheet 111 is the perpendicular bisector of the long axis. The elliptical metal sheet 111 and the strip metal sheet 112 can be made of conductive materials such as gold, silver, copper and aluminum. The specific combination of the open resonant element 110 and the reflective layer 130 can produce a strong magnetic response under the excitation of the incident polarized wave. For example, when the incident polarized wave is vertically incident to the open resonant element 110, a uniform current is generated on the surface of the open resonant element 110, thereby producing a strong magnetic response. The strong magnetic response will affect the reflection of the incident polarized wave. Since the open resonant element 110 formed by the elliptical metal sheet 111 and the strip metal sheet 112 on the resonant element 110 has anisotropy, the reflection phases of two orthogonal incident polarized waves are different, so that the reflection phase difference of the two orthogonal incident polarized waves in the working frequency band fluctuates around 180°, thereby realizing high polarization conversion efficiency.
[0049] In an embodiment, the length of the polarization conversion unit 100 along the second direction L2 can be 15 mm, and the length of the polarization conversion unit 100 along the third direction L3 can be 13.6 m; the first direction L1, the second direction L2 and the third direction L3 are perpendicular to each other. The length of the polarization conversion unit 100 along the second direction L2 can also be 15 ± 0.1 mm, and the length of the polarization conversion unit 100 along the third direction L3 can also be set to other parameters within the range of 13.6 ± 0.1 mm.
[0050] In an embodiment, the major axis of the elliptical metal sheet 111 can be 12.73 mm, the minor axis can be 11.35 mm, the thickness can be 0.035 mm, and the diagonal distance of the two openings 113 can be 11.18 mm. In addition, the major axis of the elliptical metal sheet 111 can also be set to other parameters within the range of 12.73 ± 0.1 mm, the minor axis of the elliptical metal sheet 111 can also be set to other parameters within the range of 11.35 ± 0.1 mm, the thickness of the elliptical metal sheet 111 can also be set to other parameters within the range of 0.035 ± 0.1 mm, and the diagonal distance of the two openings 113 can also be set to other parameters within the range of 11.18 ± 0.1 mm.
[0051] In an embodiment, the elliptical metal sheet 111 can be implemented by two long strip-shaped metal sheets 111a. The two long strip-shaped metal sheets 111a are bent towards the strip-shaped metal sheet 112 and arranged to be centrally symmetric, and the interval part between the two long strip-shaped metal sheets 111a is the opening 113 of the elliptical metal sheet 111.
[0052] In an embodiment, the dielectric layer 120 includes a first dielectric layer 121 and a second dielectric layer 122 arranged in sequence along the first direction L1; the dielectric constant of the first dielectric layer 121 can be 2.2, and the dielectric constant of the second dielectric layer 122 can be 1.05 ± 1. In addition, the dielectric constant of the first dielectric layer 121 can also be set to 2.2 ± 0.1.
[0053] In an embodiment, the material of the first dielectric layer 121 can include one of polyimide, silicon dioxide and epoxy resin.
[0054] In an embodiment, the material of the second dielectric layer 122 can include foam. The weight of the foam is much lighter, thereby reducing the overall weight of the polarization converter 10. The material of the second dielectric layer 122 can also be other light-weight insulating materials.
[0055] In an embodiment, the thickness of the first dielectric layer 121 can be 0.51 ± 0.1 mm.
[0056] In an embodiment, the second dielectric layer 122 can have a thickness of 7 ± 0.1 mm.
[0057] In an embodiment, the material of the reflective layer 130 can be one of gold, silver, copper, and aluminum.
[0058] Referring to Figure 3 In an embodiment, if the polarization converter 10 includes a plurality of polarization conversion units 100, the plurality of polarization conversion units 100 can be arranged in an array on a plane.
[0059] In the embodiment, the plurality of polarization conversion units 100 are arranged in an array to form a metasurface structure, which can flexibly and effectively control the phase, polarization mode, and propagation mode of electromagnetic waves. Since the polarization conversion element is small in size and light in weight, the size of the metasurface structure formed by the plurality of polarization conversion units 100 can also be reduced accordingly.
[0060] The application realizes polarization conversion through the open resonant element 110 formed by the elliptical metal sheet 111 and the strip-shaped metal sheet 112, the dielectric layer 120, and the reflective layer 130, and the resonant element 110 is small in size and light in weight, which is conducive to the miniaturization of the resonant converter.
[0061] In an embodiment, the first dielectric layer 121 is made of silicon dioxide with a dielectric constant of 2.2, and the second dielectric layer 122 is made of foam with a dielectric constant of 1.05 + i0.001 (i is the electric field loss). The length of the polarization conversion unit 100 is 15 mm, and the width is 13.6 mm. The major axis of the elliptical metal sheet 111 is 12.73 mm, the minor axis is 11.35 mm, the thickness is 0.035 mm, and the diagonal distance of the two openings 113 is 11.18 mm. The thickness of the first dielectric layer 121 is 0.51 mm. The thickness of the second dielectric layer 122 is 7 mm. The plurality of polarization conversion units 100 are arranged in an array to form a metasurface structure.
[0062] In the embodiment, since the resonant element 110 of the polarization converter 10 is an anisotropic structure, when a linearly polarized wave is vertically incident on the resonant element 110, the corresponding reflected wave will contain cross-polarization and co-polarization components. The reflection matrix Rlin (used to describe the relationship between the incident electric field and the reflected electric field) under linearly polarized wave incidence is as follows:
[0063] (1),
[0064] In the formula, the subscripts i and j correspond to the polarization states of the reflected wave and the incident wave, respectively.
[0065] When the incident wave is a circularly polarized wave, the reflection matrix Rcir based on the circularly polarized wave can be represented as:
[0066] (2)
[0067] At the same time:
[0068] (3),
[0069] In formula (1), (2), (3), the subscripts x and y represent X-polarized wave and Y-polarized wave respectively, and the subscripts + and - represent right-handed circularly polarized wave and left-handed circularly polarized wave respectively.
[0070] In the simulation process, a plane wave excitation is set to be incident along the-z axis direction to the top of the open resonant element 110, the super surface performs a periodic structure, the unit boundary conditions along the ±x and ±y directions are set, and a floquet port is applied along the z direction. Based on the finite element integral technology, the related electromagnetic properties are simulated.
[0071] When the polarization converter 10 works at room temperature, the reflection coefficients R-- and R+- (where R-- and R+- represent the reflection coefficients of co-polarized and cross-polarized waves respectively) under left-handed circularly polarized wave incidence are as shown in Figure 4 From the figure, it can be clearly seen that the circular polarization conversion efficiency of this structure is stably maintained above 95% in the frequency range of 5.3GHz-13.0GHz, and peaks of 100% appear at 5.8GHz, 7.8GHz and 12.0GHz respectively. Then, the right-handed circularly polarized wave is used to be normally incident to the polarization converter 10, and the result is basically the same as that of the left-handed circularly polarized wave incidence in Figure 4 .
[0072] PCR (polarization conversion ratio) is an important parameter used to reflect the performance of the polarizer:
[0073] (4),
[0074] Through the calculation formula (4), the PCR under left-handed circularly polarized wave incidence can be obtained, as shown in Figure 5 From the figure, the relative bandwidth of the PCR can also be calculated as 66.7%, in which and are the upper limit frequency point and the lower limit frequency point of the polarization conversion frequency higher than 90% respectively. Figure 5 The results in show that when the working environment is at room temperature, the circularly polarized wave normally incident can be almost completely reflected and converted into electromagnetic wave with the same chirality by the polarization converter 10.
[0075] Figure 6 andFigure 7 The phase and reflection coefficient of the whole working band are shown. Figure 7 It can be seen from the figure that the reflection phase of the orthogonal linearly polarized wave has almost the same phase gradient between 5.3 GHz and 13.0 GHz. And its reflection coefficient is basically stable: |RYY|=|RXX|=1. Figure 8 The calculated phase difference of the orthogonal linearly polarized wave is shown, which fluctuates in the range of (0.83, 1.05). It can be seen from the figure that there are multiple intersection points between the actual phase difference and the expected constant, corresponding to the multiple extreme values described above. And in the non-working area, the phase difference fluctuates abnormally severely, indicating that the polarization converter 10 has good frequency selectivity. Substituting the reflection coefficient and phase of all linearly polarized waves into formulas (1)-(3), the results are consistent with the expected values. This shows that the polarization state of the circularly polarized wave remains consistent before and after reflection. Therefore, the polarization converter 10 has good performance in maintaining the polarization state of the reflected wave within the working frequency range of 5.3 GHz-13.0 GHz. Figure 4
[0076] The field monitor is set at a frequency of 7.8 GHz, and the left-handed circularly polarized wave is vertically incident. Figure 9 The electric field energy density of the resonant element 110 monitored by the field monitor is shown, where the shaded part represents the electric field energy. Figure 10 The surface current distribution of the resonant element 110 is shown. From the figure, it can be seen that the surface current distribution of the resonant element 110 is not uniform, and the surface current distribution of the top elliptical metal sheet 111 is different from that of the bottom elliptical metal sheet 111. Figure 9 It can be seen from the electric energy density distribution of the resonant element 110 that the electric field energy is mainly concentrated on the opening 113 part of the elliptical metal sheet 111. Since the top elliptical metal sheet 111 is provided with two openings 113, it has anisotropy, which leads to different reflection phases of the two orthogonal polarized waves. Figure 10 The symbol P in the figure represents the effective electric dipole corresponding to the surface current. From the surface current distribution excited by the left-handed circularly polarized wave, it can be seen that the specific combination of the reverse electric dipoles on the top opening 113 (solid arrow) and the bottom reflector (dashed arrow) can induce a strong magnetic response. Because the specific combination of electric dipoles and magnetic dipoles (same direction or opposite direction, comparable size) can induce a strong planar chiral response of the incident electromagnetic wave, just like the chiral response in natural chiral molecules. That is, the polarization conversion phenomenon is closely related to the strong magnetic response caused by the resonant element 110 and the reflector. As shown in the figure, the circularly polarized wave is vertically incident, and the surface current distribution on the resonant element 110 is uniform, producing a broadband polarization effect. Figure 10
[0077] The present application also proposes a communication device, which comprises the polarization converter 10 described above. The communication device can be a micro antenna, a non-destructive detector, a 6G communication system, etc.
[0078] The detailed structure of the polarization converter 10 can refer to the above-mentioned embodiments, which will not be described here again; it can be understood that, since the polarization converter 10 is used in the communication device of the application, the embodiments of the communication device of the application include all the technical solutions of all the embodiments of the polarization converter 10, and the technical effects achieved are also completely the same, which will not be described here again. In the foregoing, the specific embodiments of the application are described with reference to the drawings. However, those skilled in the art can understand that various changes and replacements can be made to the specific embodiments of the application without departing from the spirit and scope of the application. These changes and replacements are all within the scope defined by the application.
Claims
1. A polarization converter, characterized in that: The polarization converter includes at least one polarization conversion unit; The polarization conversion unit includes a resonant element, a dielectric layer, and a reflective layer arranged in sequence along a first direction; the first direction is perpendicular to the plane where the resonant element is located; The resonant element includes an elliptical metal sheet and a strip metal sheet; both ends of the short axis of the elliptical metal sheet are respectively provided with openings; and both ends of the strip metal sheet are respectively connected to both ends of the long axis of the elliptical metal sheet.
2. The polarization converter according to claim 1, wherein The length of the polarization conversion unit along the second direction is 15±0.1 mm, and the length of the polarization conversion unit along the third direction is 13.6±0.1 m; the first direction, the second direction and the third direction are perpendicular to each other.
3. The polarization converter according to claim 1, wherein The major axis of the elliptical metal sheet is 12.73±0.1 mm, the minor axis is 11.35±0.1 mm, the thickness is 0.035±0.1 mm, and the diagonal distance between the two openings is 11.18±0.1 mm.
4. The polarization converter according to claim 1, wherein The dielectric layer includes a first dielectric layer and a second dielectric layer sequentially arranged along a first direction; the dielectric constant of the first dielectric layer is 2.2±0.1, and the dielectric constant of the second dielectric layer is 1.05±1.
5. The polarization converter according to claim 4, wherein The material of the first dielectric layer includes one of polyimide, silicon dioxide, and epoxy resin.
6. The polarization converter according to claim 4, wherein The material of the second dielectric layer includes foam.
7. The polarization converter according to claim 4, wherein The thickness of the first dielectric layer is 0.51±0.1 mm.
8. The polarization converter according to claim 4, wherein The thickness of the second dielectric layer is 7±0.1 mm.
9. The polarization converter according to claim 1, wherein A plurality of polarization conversion units are arranged in an array on a plane.
10. A communication device, characterized in that: The communication device comprises the polarization converter according to any one of claims 1 to 9.