Reflection type polarization rotator

Abstract

The utility model provides a reflection type polarization rotator which comprises a reflection bottom plate, a dielectric layer and a metal patch, the reflection bottom plate is used for reflecting electromagnetic waves, the dielectric layer is arranged on the upper surface of the reflection bottom plate, the metal patch is arranged on the upper surface of the dielectric layer, and the horizontal section of the metal patch is of a structure shaped like a Chinese character'wang '. And the center line of the structure shaped like the Chinese character'wang 'is inclined to the horizontal polarization direction and the vertical polarization direction. The reflection type polarization rotator provided by the utility model has wider working bandwidth and higher polarization conversion efficiency, and is simple in structure and more convenient to process and apply.

Description

Technical Field

[0001] The present application relates to the technical field of electromagnetic wave polarization, and in particular to a reflective polarization rotator. Background Art

[0002] The polarization of electromagnetic waves refers to the trajectory of the electric field vector end at any given point in space as it changes over time. Electromagnetic waves have many strange phenomena that are closely related to the polarization state of electromagnetic waves. Therefore, controlling the polarization of electromagnetic waves is an important research topic in the spatial propagation of electromagnetic waves.

[0003] When controlling the polarization of electromagnetic waves, a polarization rotator can be used to rotate the polarization direction of the electromagnetic waves by a certain angle while maintaining the polarization characteristics of the electromagnetic waves. However, in order to increase the working bandwidth and polarization conversion efficiency of the polarization rotator, the structure of the polarization rotator is usually designed to be very complex, which is not convenient for the processing and application of polarization rotator devices. Utility Model Content

[0004] The present application provides a reflective polarization rotator, aiming to increase the working bandwidth and polarization conversion efficiency of the polarization rotator while simplifying the structure of the polarization rotator.

[0005] The reflective polarization rotator provided in the present application comprises:

[0006] A reflective bottom plate for reflecting electromagnetic waves;

[0007] A dielectric layer, disposed on the upper surface of the reflective bottom plate;

[0008] The metal patch is arranged on the upper surface of the dielectric layer. The horizontal cross section of the metal patch is a W-shaped structure, and the center line of the W-shaped structure is inclined to the horizontal polarization direction and the vertical polarization direction.

[0009] In a possible implementation of the present application, the angles between the center line of the Chinese-W-shaped structure and the horizontal polarization direction and the vertical polarization direction are both 45°.

[0010] In a possible implementation of the present application, the W-shaped structure includes a first rectangular member, a second rectangular member and a third rectangular member, the first rectangular member, the second rectangular member and the third rectangular member are parallel to each other along the length direction, and one long side of the third rectangular member is connected to the first rectangular member through a first connecting portion, and the other long side of the third rectangular member is connected to the second rectangular member through a second connecting portion.

[0011] In a possible implementation of the present application, the W-shaped structure is a centrally symmetrical structure.

[0012] In a possible implementation of the present application, the width direction of the third rectangular member is perpendicular to the width direction of the first connecting portion, the width of the third rectangular member is greater than the width of the first connecting portion, and the length of the third rectangular member is greater than the length of the first rectangular member.

[0013] In a possible implementation of the present application, the length of the third rectangular piece is 1.7 mm and the width is 1.1 mm, the length of the first connecting part and the second connecting part are both 3.8 mm and the width are both 0.12 mm, and the length of the first rectangular piece and the second rectangular piece are both 1 mm.

[0014] In a possible implementation of the present application, the reflective polarization rotator is a periodic structure, which includes a plurality of periodic units, and each of the periodic units includes a base plate in the reflective base plate, a dielectric block in the dielectric layer, and a metal patch, a plurality of the base plates form the reflective base plate, and a plurality of the dielectric blocks form the dielectric layer.

[0015] In a possible implementation of the present application, the length and width of the dielectric block in each of the periodic units are both 3.9 mm, and the height is 1.5 mm.

[0016] In a possible implementation of the present application, the dielectric layer is made of polytetrafluoroethylene material, and the dielectric constant of the polytetrafluoroethylene material is 2.65.

[0017] In a possible implementation of the present application, the metal patch is a copper sheet, and the thickness of the copper sheet is 0.017 mm.

[0018] The reflective polarization rotator provided in the embodiment of the present application comprises a reflective bottom plate, a dielectric layer and a metal patch, wherein the reflective bottom plate is used to reflect electromagnetic waves, the dielectric layer is arranged on the upper surface of the reflective bottom plate, the metal patch is arranged on the upper surface of the dielectric layer, the horizontal cross section of the metal patch is a W-shaped structure, and the center line of the W-shaped structure is inclined to the horizontal polarization direction and the vertical polarization direction. The reflective polarization rotator provided in the present application sets the horizontal cross section of the metal patch to a W-shaped structure, and sets it inclined to the horizontal polarization direction and the vertical polarization direction, so that when the polarization direction of the electromagnetic wave is rotated, a wider working bandwidth and a higher polarization conversion efficiency can be achieved, and the structure is simple, and the processing and application are more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of a three-dimensional structure of a reflective polarization rotator provided in an embodiment of the present application;

[0021] Figure 2 is a structural schematic diagram of a horizontal cross section of a metal patch provided in an embodiment of the present application;

[0022] Figure 3 is a simulation diagram of the reflection coefficient of the reflective polarization rotator provided in the embodiment of the present application;

[0023] Figure 4 This is a simulation diagram of the polarization conversion rate of the reflective polarization rotator provided in the embodiment of the present application.

[0024] Description of reference numerals:

[0025] 1. Reflection bottom plate; 2. Dielectric layer; 3. Metal patch; 31. First rectangular piece; 32. Second rectangular piece; 33. Third rectangular piece; 34. First connecting part; 35. Second connecting part. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0027] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0028] In this application, the term "in some embodiments" is used to mean "used as an example, illustration or description". Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. In order to enable any technician in the field to implement and use the present application, the following description is given. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest range of structures and features disclosed in the present application.

[0029] In the related art, during the propagation of linearly polarized electromagnetic waves (such as horizontally polarized electromagnetic waves or vertically polarized electromagnetic waves) in free space, due to the complexity of space, after multiple reflections and refractions, its polarization direction will be deflected. If the polarization direction of the linearly polarized electromagnetic wave forms a certain angle with the polarization direction of the receiving antenna, polarization loss will occur. When the angle is 90 degrees, the energy of the linearly polarized electromagnetic wave can hardly be received. For example, in the study of radar anti-interference, if the other party transmits a horizontally polarized wave, our vertically polarized antenna will not receive the signal. Therefore, through the reflective polarization rotator provided in the embodiment of the present application, the horizontal cross-section of the metal patch can be set to a W-shaped structure, and it can be set to be inclined to the horizontal polarization direction and the vertical polarization direction, so that when the polarization direction of the electromagnetic wave is rotated, a wider working bandwidth and a higher polarization conversion efficiency can be achieved, and the structure is simple, and processing and application are more convenient.

[0030] like Figure 1 As shown, Figure 1 A schematic diagram of a three-dimensional structure of a reflective polarization rotator provided in an embodiment of the present application. The reflective polarization rotator of the present application can be applied to millimeter wave antenna products, and can also be applied to antenna products of other waves, such as ultra-long wave, long wave, medium wave, short wave, ultra-short wave, etc., which is not limited in the present application. The reflective polarization rotator can be specifically used to realize functions such as target detection, identification, encoding and sampling, and is widely used in satellite communications, radar reception anti-interference, aerospace and medical fields.

[0031] exist Figure 1 In the embodiment, the reflective polarization rotator comprises a reflective bottom plate 1, a dielectric layer 2 and a metal patch 3. The dielectric layer 2 is arranged on the upper surface of the reflective bottom plate 1, and the metal patch 3 is arranged on the upper surface of the dielectric layer 2.

[0032] The reflective bottom plate 1 is used to reflect electromagnetic waves. For example, the reflective bottom plate 1 can completely reflect the electromagnetic waves that pass through the dielectric layer 2 .

[0033] The dielectric layer 2 is used to generate phase accumulation of electromagnetic waves inside the reflective polarization rotator to meet the requirements of polarization conversion. In some embodiments, the dielectric layer 2 is made of polytetrafluoroethylene (PTFE) material, and the dielectric constant of the polytetrafluoroethylene material can be set to 2.65.

[0034] The horizontal cross section of the metal patch 3 is a W-shaped structure, and the center line of the W-shaped structure is inclined to the horizontal polarization direction and the vertical polarization direction. The horizontal polarization direction means that when the satellite transmits an electromagnetic wave signal to the ground, the vibration direction of the electromagnetic wave signal is horizontal, and the vertical polarization direction means that when the satellite transmits an electromagnetic wave signal to the ground, the vibration direction of the electromagnetic wave signal is vertical. Generally, the "horizontal" and "vertical" directions are determined with reference to the surface of the earth. It is usually agreed that the x direction is defined as the horizontal direction, the y direction is defined as the vertical direction, and the z direction is the normal direction of the earth's surface. The x direction, the y direction, and the z direction are perpendicular to each other in three-dimensional space.

[0035] When a linearly polarized electromagnetic wave is incident on the reflective polarization rotator, a coupling effect occurs between the reflective base plate 1 and the metal patch 3, and the electromagnetic wave is radiated outward. The direction of the electric field intensity formed during the radiation (i.e., the polarization direction of the reflective polarization rotator) often coincides with the center line of the metal patch 3. Therefore, when the center line of the W-shaped structure is inclined to the horizontal polarization direction and the vertical polarization direction, the polarization direction of the reflective polarization rotator is also inclined to the horizontal polarization direction and the vertical polarization direction at the same angle.

[0036] In the above embodiment, by adopting a metal patch 3 with a horizontal cross-section in the shape of a Chinese character "W", and the center line of the Chinese character "W" is inclined to the horizontal polarization direction and the vertical polarization direction, the reflective polarization rotator can have a wider working bandwidth, lower polarization loss, and higher polarization conversion efficiency.

[0037] The following is an explanation of the reflection working process of the reflection type polarization rotator: Taking the incident electromagnetic wave as a horizontally polarized electromagnetic wave as an example, the horizontally polarized electromagnetic wave is incident on the reflection type polarization rotator and first contacts the metal patch 3. The metal patch 3 can generate electromagnetic resonance when electromagnetic waves of some frequencies are incident and reflect the electromagnetic waves of these frequencies, while electromagnetic waves of other frequencies can be incident on the dielectric layer 2 for propagation. When the electromagnetic wave propagates in the dielectric layer 2, the electric field vector E of the electromagnetic wave can be in (Electric field vector E inThe direction is the horizontal polarization direction), and in the plane perpendicular to the incident direction of the electromagnetic wave, it is decomposed into two mutually perpendicular electric field components E1 and E2 (the direction of the electric field component E2 is the polarization direction of the reflection-type polarization rotator). Due to the anisotropic characteristics of the metasurface of the dielectric layer 2 and the coupling effect between the reflection bottom plate 1 and the metal patch 3, the phase velocities of E1 and E2 in the dielectric layer 2 are inconsistent, and thus a phase difference is generated when E1 and E2 propagate in the dielectric layer 2. By setting the height of the dielectric layer 2, this phase difference can be made an odd multiple of π. At this time, after E1 is reflected by the reflection bottom plate 1 and exits from the reflection-type polarization rotator, E3 is obtained, and E3 is out of phase with E1. After E2 is reflected by the reflection bottom plate 1, the phase does not change when it exits from the reflection-type polarization rotator. The resultant vector of E3 and E1 is the electric field vector E of the electromagnetic wave exiting from the reflection-type polarization rotator out , it can be seen that E out relative to E in rotates by a certain angle, so that the horizontally polarized electromagnetic wave can be deflected into a vertically polarized electromagnetic wave.

[0038] In some embodiments, the central line of the king-shaped structure forms an angle of 45° with both the horizontal polarization direction and the vertical polarization direction. Of course, the angle between the central line of the king-shaped structure and the horizontal polarization direction or the vertical polarization direction can also be other angles, such as 44°, 46°, etc.

[0039] In some embodiments, the metal patch 3 can be a copper sheet, and the thickness of the copper sheet can be set to 0.017 millimeters.

[0040] In some embodiments, as Figure 2 shown, the king-shaped structure includes a first rectangular member 31, a second rectangular member 32, and a third rectangular member 33. The first rectangular member 31, the second rectangular member 32, and the third rectangular member 33 are parallel to each other in the length direction, and one long side of the third rectangular member 33 is connected to the first rectangular member 31 through a first connecting portion 34, and the other long side of the third rectangular member 33 is connected to the second rectangular member 32 through a second connecting portion 35, thereby forming a king-shaped structure. Among them, the shapes of the first connecting portion 34 and the second connecting portion 35 are also rectangular, and the first rectangular member 31, the second rectangular member 32, the third rectangular member 33, the first connecting portion 34, and the second connecting portion 35 are integrally formed.

[0041] In some embodiments, the king-shaped structure is a centrosymmetric structure, for example Figure 2As shown in , the Chinese-shaped structure is not only axially symmetrically arranged relative to the center line of the third rectangular member 33 along the length direction, but also axially symmetrically arranged relative to the center line of the third rectangular member 33 along the width direction, thereby forming a centrally symmetrical structure. Since the Chinese-shaped structure is a centrally symmetrical structure, according to the above-mentioned reflection working process of the reflection type polarization rotator, the electric field vector of the electromagnetic wave in the vertical polarization direction incident on the reflection type polarization rotator can also be deflected by a certain angle to obtain an electromagnetic wave in the horizontal polarization direction, that is, the reflection type polarization rotator is not only suitable for the incident electromagnetic wave with horizontal polarization, but also for the incident electromagnetic wave with vertical polarization.

[0042] In some embodiments, Figure 2 As shown, the width direction of the third rectangular member 33 is perpendicular to the width direction of the first connecting portion 34, and the width of the third rectangular member 33 is greater than the width of the first connecting portion 34, and the length of the third rectangular member 33 is greater than the length of the first rectangular member 31. For example, the width b of the third rectangular member 33 can be 1.1 mm, the width w of the first connecting portion 34 can be 0.12 mm, the length a of the third rectangular member 33 can be 1.7 mm, and the length g of the first rectangular member 31 can be 1 mm.

[0043] In some embodiments, Figure 2 As shown, the values ​​of some dimensional parameters of the reflective polarization rotator are exemplified: the length a of the third rectangular piece 33 is 1.7 mm, the width b is 1.1 mm, the length l of the first connecting part 34 and the second connecting part 35 are both 3.8 mm, the width w is both 0.12 mm, and the length g of the first rectangular piece 31 and the second rectangular piece 32 are both 1 mm.

[0044] In some embodiments, the reflective polarization rotator is a periodic structure, and the periodic structure includes a plurality of periodic units, that is, the reflective polarization rotator includes a plurality of periodic units (e.g., m*n periodic units) arranged in a periodic combination. Each periodic unit includes a base plate in the reflective base plate 1, a dielectric block in the dielectric layer 2, and a metal patch 3. The plurality of base plates form the reflective base plate 1, and the plurality of dielectric blocks form the dielectric layer 2.

[0045] In some embodiments, Figure 1 As shown, the length and width of the dielectric block in each periodic unit are both p (p can be, for example, 3.9 mm), and the height is h (h can be, for example, 1.5 mm).

[0046] In some embodiments, a simulation test using the above-mentioned reflective polarization rotator is exemplified:

[0047] The boundary conditions of the simulation test of the reflection-type polarization rotator are set to periodic boundary conditions (PBC). In three-dimensional electromagnetic simulation software such as HFSS (High Frequency Structure Simulator), the floquet ports (Floquet Ports) are set to be excited as TE waves (Transverse Electric wave) and TM waves (Transverse Magnetic wave), that is, x-polarization (i.e. horizontal polarization) and y-polarization (i.e. vertical polarization) plane waves are used for incident respectively, and the incident wave is incident along the -z direction.

[0048] Figure 3 is a simulation diagram of the reflection coefficient of a reflective polarization rotator, where R yx represents the cross-polarization reflection coefficient, R xx represents the co-polarization coefficient. Figure 3 It can be seen that when an x-polarized plane wave is incident, the reflection coefficient R of the reflective polarization rotator in the frequency band of 15 GHz to 45 GHz is xx Basically less than -10dB, cross-polarization coefficient R yx It is close to 0dB, which means that the reflective polarization rotator can rotate the incident x-polarized wave by 90° and convert it into a y-polarized wave that is reflected back.

[0049] Figure 4 This is a simulation diagram of the polarization conversion ratio (PCR) of a reflective polarization rotator. Figure 4 It can be seen that the polarization conversion rate of the reflective polarization rotator in the frequency band of 17 GHz-42 GHz is higher than 90%, that is, the reflective polarization rotator has a higher polarization conversion efficiency.

[0050] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0051] The above is a detailed introduction to a reflective polarization rotator provided in an embodiment of the present application. Specific examples are used in this article to illustrate the structure and implementation methods of the present application. The description of the above embodiments is only used to help understand the structure of the present application and its core idea; at the same time, for technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A reflection type polarization rotator, characterized in that: The reflective polarization rotator comprises: A reflective bottom plate for reflecting electromagnetic waves; A dielectric layer, disposed on the upper surface of the reflective bottom plate; The metal patch is arranged on the upper surface of the dielectric layer. The horizontal cross section of the metal patch is a W-shaped structure, and the center line of the W-shaped structure is inclined to the horizontal polarization direction and the vertical polarization direction.

2. The reflective polarization rotator according to claim 1, wherein: The included angles between the center line of the Chinese-W-shaped structure and the horizontal polarization direction and the vertical polarization direction are both 45°.

3. The reflection type polarization rotator according to claim 1, wherein: The W-shaped structure includes a first rectangular member, a second rectangular member and a third rectangular member, wherein the first rectangular member, the second rectangular member and the third rectangular member are parallel to each other along the length direction, and one long side of the third rectangular member is connected to the first rectangular member through a first connecting portion, and the other long side of the third rectangular member is connected to the second rectangular member through a second connecting portion.

4. The reflection type polarization rotator according to claim 3, characterized in that: The W-shaped structure is a centrally symmetrical structure.

5. The reflection type polarization rotator according to claim 4, wherein: The width direction of the third rectangular member is perpendicular to the width direction of the first connecting portion, and the width of the third rectangular member is greater than the width of the first connecting portion. The length of the third rectangular member is greater than the length of the first rectangular member.

6. The reflection type polarization rotator according to any one of claims 3 to 5, characterized in that: The length of the third rectangular piece is 1.7 mm and the width is 1.1 mm. The length of the first connecting portion and the second connecting portion are both 3.8 mm and 0.12 mm in width. The length of the first rectangular piece and the second rectangular piece are both 1 mm.

7. The reflection type polarization rotator according to claim 6, wherein: The reflective polarization rotator is a periodic structure, which includes a plurality of periodic units, and each of the periodic units includes a base plate in the reflective base plate, a dielectric block in the dielectric layer, and a metal patch. A plurality of base plates form the reflective base plate, and a plurality of dielectric blocks form the dielectric layer.

8. The reflection type polarization rotator according to claim 7, wherein: The length and width of the dielectric block in each of the periodic units are both 3.9 mm, and the height is 1.5 mm.

9. The reflection type polarization rotator according to claim 1, wherein: The dielectric layer is made of polytetrafluoroethylene material, and the dielectric constant of the polytetrafluoroethylene material is 2.

65.

10. The reflective polarization rotator according to claim 1, wherein: The metal patch is a copper sheet, and the thickness of the copper sheet is 0.017 mm.

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