Adjustable phase line-to-circular polarization converter based on three-layer metasurface
By designing the phase compensation technology of the three-layer metasurface structure and the stripline layer, the existing transmission array antenna structure is solved, and efficient line-to-circular polarization conversion is achieved, with good matching characteristics and frequency bands performance.
Patent Information
- Application Number
- CN202421078901.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2024-12-20
- Estimated Expiration
- Not applicable · inactive patent
Smart Images
Figure CN222214475U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of wireless communications, and in particular to an adjustable phase line to circular polarization converter based on a three-layer metasurface. Background Art
[0002] With the continuous development of society, a new generation of wireless communication technology has emerged. People's requirements for communication are getting higher and higher, and the society's demand for frequency band resources is also getting higher and higher. Therefore, large bandwidth has become an important indicator of today's communication-related technologies. Satellite communications have many unused high-frequency band resources, which has become a key research direction today; satellite communications usually need to meet the characteristics of high gain and circular polarization, so transmission array antennas, as a high-gain antenna, have become an excellent option. On the other hand, in order to achieve circularly polarized electromagnetic waves, generally speaking, a circularly polarized feed is required, but the circularly polarized feed is usually complex in structure and expensive. Therefore, using a linearly polarized feed and realizing circular polarization characteristics through a metasurface has become a research direction today.
[0003] For example, Chinese patent CN209056606U discloses an ultra-wideband linear-circular polarization converter in the S band, including a bottom metal reflector, a first dielectric layer, an intermediate layer metal resonance unit placed between the two dielectric layers, a second dielectric layer and a top metal resonance unit stacked in sequence from bottom to top; the top metal resonance unit is a cross-shaped structure, the intermediate layer metal resonance unit is an elliptical structure, and the elliptical structure has a groove inside.
[0004] However, the technology has the following problems: the antenna does not have good matching characteristics, and the matching characteristics of a single metasurface layer are very poor. Without relying on a complex feeding network, the function of linear-to-circular polarization cannot be well achieved simply by the polarization conversion capability of the metasurface.
[0005] Based on this, the utility model designs an adjustable phase line to circular polarization converter based on a three-layer metasurface to solve the above problems. Utility Model Content
[0006] In view of the above-mentioned shortcomings of the prior art, the utility model provides an adjustable phase line to circular polarization converter based on a three-layer metasurface.
[0007] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:
[0008] An adjustable phase line to circular polarization converter based on a three-layer metasurface, comprising a PCB dielectric substrate and a metal layer;
[0009] The PCB dielectric substrate includes, from top to bottom, a top dielectric layer, an upper middle dielectric layer, an intermediate dielectric layer, a lower middle dielectric layer, a lower dielectric layer and a bottom dielectric layer;
[0010] The metal layers include, from top to bottom, a top metal patch layer, a second top metal patch layer, a middle metal patch layer, an upper ground layer, a stripline layer and a lower ground layer.
[0011] Furthermore, the top views of the top metal patch layer, the top dielectric layer, the next top metal patch layer, the middle upper dielectric layer, the middle metal patch layer, the middle dielectric layer, the upper ground layer, the middle lower dielectric layer, the stripline layer, the lower dielectric layer, the lower ground layer and the bottom dielectric layer are all squares.
[0012] Furthermore, the top metal patch layer, the top dielectric layer, the next top metal patch layer, the middle upper dielectric layer, the middle metal patch layer, the middle dielectric layer, the upper ground layer, the middle lower dielectric layer, the stripline layer, the lower dielectric layer, the lower ground layer and the bottom dielectric layer are distributed in sequence from top to bottom.
[0013] Furthermore, the top metal patch layer, the second top metal patch layer, and the middle metal patch layer are the same, and are all uniformly distributed square-cut super surface layers.
[0014] Furthermore, the upper ground layer and the lower ground layer are each etched with two slits that are symmetrical about the center of the converter.
[0015] Furthermore, the upper ground layer can be regarded as the lower ground layer rotated 90°, the gap of the upper ground layer is parallel to the Y axis, and the gap of the lower ground layer is parallel to the X axis, and the sizes of the upper ground layer and the lower ground layer are the same.
[0016] Furthermore, the stripline layer consists of two striplines, and the two striplines are symmetrical about the center of the converter.
[0017] Furthermore, the patch shapes of the top metal patch layer, the second top metal patch layer, and the middle metal patch layer include but are not limited to square and cut-angle shapes, and also include leaf shapes, cross shapes, and square cut-angle shapes.
[0018] Furthermore, the shapes of the gap ends of the upper ground layer and the lower ground layer include, but are not limited to, rectangles, and also include sectors and triangles.
[0019] Furthermore, the stripline layer can achieve phase compensation by changing the length of the stripline, and the shape of the matching terminal of the stripline includes but is not limited to a rectangle, and also includes a fan-shaped and a triangle.
[0020] The utility model has the following technical effects:
[0021] 1. The utility model uses a strip line as a true delay line for phase compensation. The phase can be changed by simply adjusting the length of the strip line. The adjustment is convenient and a linear phase can be achieved within a wider frequency band.
[0022] 2. The utility model has a polarization twisting function, and the two ends of the strip line are 90 degrees, which can convert the electromagnetic wave in the X polarization direction into the electromagnetic wave in the Y polarization direction. It uses a linear polarization feed source, which is low in cost and more practical.
[0023] 3. The utility model uses standard PCB technology, which is easy to produce and can be mass-produced to meet commercial needs. The utility model uses three layers of super surface layers with good matching characteristics. The utility model has a polarization selection function, which can filter out electromagnetic waves in other directions and only pass incident waves in the X-polarization direction. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0025] Figure 1 The utility model is a specific structure of an adjustable phase line to circular polarization converter based on a three-layer metasurface;
[0026] Figure 2 It is a schematic diagram of the top metal patch layer of the utility model;
[0027] Figure 3 A schematic diagram of an upper grounding layer of the present utility model;
[0028] Figure 4 is a schematic diagram of a stripline layer of the utility model;
[0029] Figure 5 It is a schematic diagram of the lower grounding layer of the utility model;
[0030] Figure 6 It is a schematic diagram of the bottom metal patch layer of the utility model;
[0031] Figure 7 It is a curve diagram of the amplitude simulation of the electromagnetic wave of the utility model;
[0032] Figure 8 This is a phase simulation curve diagram of the electromagnetic wave of the utility model.
[0033] The numbers in the figure represent:
[0034] 1. Top metal patch layer; 2. Top dielectric layer; 3. Next top metal patch layer; 4. Middle upper dielectric layer; 5. Middle metal patch layer; 6. Middle dielectric layer; 7. Upper ground layer; 8. Middle lower dielectric layer; 9. Stripline layer; 10. Lower dielectric layer; 11. Lower ground layer; 12. Bottom dielectric layer; 13. Bottom metal patch layer. DETAILED DESCRIPTION
[0035] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0036] The utility model is further described below in conjunction with embodiments.
[0037] Example 1
[0038] Please refer to the instruction manual Figure 1-8 , an adjustable phase line to circular polarization converter based on a three-layer metasurface, comprising a PCB dielectric substrate and a metal layer;
[0039] The PCB dielectric substrate includes, from top to bottom, a top dielectric layer 2, an upper middle dielectric layer 4, an intermediate dielectric layer 6, a lower middle dielectric layer 8, a lower dielectric layer 10 and a bottom dielectric layer 12;
[0040] The metal layers include, from top to bottom, a top metal patch layer 1 , a second top metal patch layer 3 , an intermediate metal patch layer 5 , an upper ground layer 7 , a stripline layer 9 and a lower ground layer 11 .
[0041] The converter receives linearly polarized waves by the bottom metal patch layer 13, and only passes the electromagnetic waves in the X-polarization direction after filtering by the lower ground layer 11. After polarization twisting and phase compensation, it is converted into circularly polarized waves through the top metal patch layer 1, the second top metal patch layer 3, and the middle metal patch layer 5, and then transmitted to the free space.
[0042] Example 2
[0043] like Figure 1-8 As shown, as a preferred embodiment of the utility model, the top metal patch layer 1, the top dielectric layer 2, the second top metal patch layer 3, the middle upper dielectric layer 4, the middle metal patch layer 5, the middle dielectric layer 6, the upper ground layer 7, the middle lower dielectric layer 8, the stripline layer 9, the lower dielectric layer 10, the lower ground layer 11 and the bottom dielectric layer 12 are all square in top view.
[0044] The top metal patch layer 1, the top dielectric layer 2, the second top metal patch layer 3, the middle upper dielectric layer 4, the middle metal patch layer 5, the middle dielectric layer 6, the upper ground layer 7, the middle lower dielectric layer 8, the stripline layer 9, the lower dielectric layer 10, the lower ground layer 11 and the bottom dielectric layer 12 are arranged in sequence from top to bottom.
[0045] The top metal patch layer 1, the second top metal patch layer 3, and the middle metal patch layer 5 are the same, and are all uniformly distributed square-cut super surface layers.
[0046] Three metasurface layers are designed. When the metasurface has multiple layers, a resonant cavity is formed between the structure and the ground layer. Electromagnetic waves are reflected back and forth between the resonant cavities, and the transmitted electromagnetic waves are superimposed in phase on the other side, thereby improving the matching characteristics of the converter and increasing the polarization bandwidth.
[0047] The dielectric constant ε of the PCB board r is [2.2, 10.2], the thickness is [0.01λ, 0.2λ], the thickness of the ground layer is [0.001λ, 0.1λ], where λ is the free space wavelength.
[0048] The adjustable phase line to circular polarization converter based on the three-layer metasurface has an overall square structure with a side length a of [0.4λ,λ].
[0049] The side length sur_w of the three-layer metal super surface layer patch is [0.05λ, 0.5λ], and the gap sur_s between each patch is [0.01λ, 0.1λ]. The shape, size and patch of the three-layer super surface layer are consistent. The patch cut corners are two squares, and the side length cut range is [0.02λ, 0.2λ].
[0050] The upper ground layer 7 and the lower ground layer 11 are each etched with two gaps that are symmetrical about the center of the converter; energy is coupled through the gaps.
[0051] The upper ground layer 7 can be regarded as the lower ground layer 11 rotated 90 degrees, the gap of the upper ground layer 7 is parallel to the Y axis, and the gap of the lower ground layer 11 is parallel to the X axis.
[0052] The upper ground layer 7 and the lower ground layer 11 have the same size, and the gaps between the upper ground layer 7 and the lower ground layer 11 can be regarded as orthogonal to each other. The upper gap size sl ot_w1 is [0.02λ, 0.2λ], sl ot_l 1 is [0.02λ, 0.15λ], sl ot_l is [0.1λ, 0.8λ], and sl ot_w is [0.01λ, 0.08λ]; where λ is the free space wavelength.
[0053] The stripline layer 9 is composed of two striplines, which are symmetrical about the center of the converter and can be used for phase compensation by adjusting their lengths.
[0054] The top metal patch layer 1, the second top metal patch layer 3, the middle metal patch layer 5, the upper ground layer 7, the stripline layer 9, and the lower ground layer 11 of the adjustable phase line to circular polarization converter based on the three-layer metasurface have patch shapes including but not limited to square and cut-angle types, and also include other shapes such as leaf type, cross type, square cut-angle type, etc.
[0055] The shapes of the gap ends of the upper ground layer 7 and the lower ground layer 11 of the adjustable phase line to circular polarization converter based on the three-layer metasurface include but are not limited to rectangles, and also include other shapes such as sectors and triangles.
[0056] The adjustable phase line to circular polarization converter based on the three-layer metasurface can achieve phase compensation by changing the length of the strip line. The shape of the matching terminal of the strip line includes but is not limited to a rectangle, and also includes other shapes such as a fan-shaped and a triangle.
[0057] The electromagnetic waves are received by the bottom metal patch layer 13 and transmitted to the lower ground layer 11 through the bottom dielectric layer 12. The two gaps of the lower ground layer 11 are parallel to the X axis, so it has polarization selection characteristics. Only X-polarized electromagnetic waves can pass through the lower ground layer 11.
[0058] Afterwards, the X-polarized electromagnetic wave reaches the stripline layer 9. The stripline is 90° from head to tail, which can twist the X-polarized electromagnetic wave into Y-polarized. The upper ground layer 7 is parallel to the Y axis, which is just coupled. The electromagnetic wave can be transmitted to the super surface layer. The upper three super surface layers have the same structure. Its function is to convert linearly polarized electromagnetic waves into circularly polarized electromagnetic waves. It is the core part of the polarization converter.
[0059] Example 3
[0060] like Figure 1-8 As shown, as a preferred embodiment of the utility model, the stripline width mi c_w is [0.01λ, 0.2λ], the stripline length is l ength=l 1+l 2+l 3+l 4+l 5+l 6+l 7+l 8, its size is [0.2λg, 2λg], the rectangular length match_w at both ends of the stripline is [0.01λ, 0.1λ], and the width match_l is [0.01λ, 0.1λ]. Phase compensation is achieved by adjusting the stripline length, wherein λg is the medium wavelength and λ is the free space wavelength.
[0061] Figure 7 This is the result obtained by simulation using the fl oquet mode in HFSS software; xxis the reflection coefficient, which indicates the amplitude of the electromagnetic wave incident in the X-polarization direction and then reflected in the X-polarization direction, and also indicates the impedance matching characteristics of the polarization converter; xx It represents the amplitude of the electromagnetic wave incident in the X-polarization direction and transmitted into the free space along the X-direction, t xy It represents the amplitude of the electromagnetic wave incident in the X-polarization direction and transmitted into the free space along the Y direction;
[0062] Combination Figure 8 , It represents the phase of the electromagnetic wave incident in the X-polarization direction and emitted in the X-polarization direction. It represents the phase of the electromagnetic wave incident in the X-polarization direction and emitted in the Y-polarization direction; and It represents the difference between the former and the latter, Figure 8 It can be seen that the linear phase characteristic of the electromagnetic wave is good, and the outgoing wave is decomposed into the X polarization direction and the Y polarization direction, and their phase difference is close to 90°, indicating that the utility model successfully realizes circular polarization.
[0063] At the same time, combined Figure 7 and Figure 8 It can be seen that the bandwidth coincidence that meets the circular polarization conditions is good, indicating that the utility model has a good bandwidth while realizing linear circular polarization.
[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. An adjustable phase line to circular polarization converter based on a three-layer metasurface, comprising a PCB dielectric substrate and a metal layer, characterized in that: The PCB dielectric substrate comprises, from top to bottom, a top dielectric layer (2), an upper middle dielectric layer (4), an intermediate dielectric layer (6), a lower middle dielectric layer (8), a lower dielectric layer (10) and a bottom dielectric layer (12); The metal layers include, from top to bottom, a top metal patch layer (1), a second top metal patch layer (3), an intermediate metal patch layer (5), an upper ground layer (7), a stripline layer (9) and a lower ground layer (11).
2. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 1 is characterized in that: The top metal patch layer (1), the top dielectric layer (2), the second top metal patch layer (3), the middle upper dielectric layer (4), the middle metal patch layer (5), the middle dielectric layer (6), the upper grounding layer (7), the middle lower dielectric layer (8), the stripline layer (9), the lower dielectric layer (10), the lower grounding layer (11) and the bottom dielectric layer (12) are all in the shape of a square in top view.
3. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 2 is characterized in that: The top metal patch layer (1), the top dielectric layer (2), the second top metal patch layer (3), the middle upper dielectric layer (4), the middle metal patch layer (5), the middle dielectric layer (6), the upper grounding layer (7), the middle lower dielectric layer (8), the stripline layer (9), the lower dielectric layer (10), the lower grounding layer (11) and the bottom dielectric layer (12) are arranged in sequence from top to bottom.
4. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 3 is characterized in that: The top metal patch layer (1), the second top metal patch layer (3), and the middle metal patch layer (5) are the same and are all uniformly distributed square-cut super surface layers.
5. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 4 is characterized in that: The upper grounding layer (7) and the lower grounding layer (11) are each etched with two slits that are symmetrical about the center of the converter.
6. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 5 is characterized in that: The upper grounding layer (7) can be regarded as the lower grounding layer (11) rotated 90 degrees, the gap of the upper grounding layer (7) is parallel to the Y axis, and the gap of the lower grounding layer (11) is parallel to the X axis, and the upper grounding layer (7) and the lower grounding layer (11) have the same size.
7. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 6 is characterized in that: The stripline layer (9) consists of two striplines, and the two striplines are symmetrical about the center of the converter.
8. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 7 is characterized in that: The patch shapes of the top metal patch layer (1), the second top metal patch layer (3), and the middle metal patch layer (5) include, but are not limited to, square and cut-corner shapes, and also include leaf shapes, cross shapes, and square cut-corner shapes.
9. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 8 is characterized in that: The shapes of the gap ends of the upper ground layer (7) and the lower ground layer (11) include, but are not limited to, rectangles, and also include sectors and triangles.
10. The adjustable phase line to circular polarization converter based on three-layer metasurface according to claim 9 is characterized in that: The stripline layer (9) can achieve phase compensation by changing the length of the stripline, and the shape of the matching terminal of the stripline includes but is not limited to a rectangle, and also includes a fan-shaped or a triangle.