Reconfigurable broadband transmission type linear polarization regulator

Abstract

The invention discloses a reconfigurable broadband transmission type linear polarization regulator, and relates to the technical field of microwaves, the polarization regulator comprises a polarization regulator body, a plurality of polarization regulation units are arranged in the polarization regulator body, and the polarization regulator body is formed by periodically arranging N * N polarization regulation units along x and y directions. The device is small in size, simple in structure and convenient to produce, the regulation and control effect from x-polarization incident waves to y-polarization transmission waves is achieved, line-line polarization regulation and control can be switched between a low-frequency mode and a high-frequency mode by controlling the working state of the PIN diode, switching and adjustment are convenient, the angle stability reaches 45 degrees, and compared with other design of the invention, the device has the advantages that the device is simple in structure and convenient to operate. According to the invention, the dual functions of polarization regulation and frequency reconstruction are realized at the same time, and the antenna has the advantages of wide band, high efficiency, low loss and high angle stability.

Description

Technical Field

[0001] The present invention relates to the field of microwave technology, and specifically to a reconfigurable broadband transmissive linear polarization controller. Background Art

[0002] As one of the polarization modes of electromagnetic waves, linear polarization plays a crucial role in the field of wireless communication. Its unique properties ensure the directionality and stability of signals during transmission, which is of great significance for improving the performance and reliability of communication systems. In wireless communication systems, both the transmitting end and the receiving end are equipped with corresponding linearly polarized antennas to ensure signal transmission and reception. By controlling the polarization direction of the antennas, signal attenuation and interference can be significantly reduced, thereby improving communication quality. In addition, linear polarization control introduces additional degrees of freedom into wireless communication systems, such as frequency reuse and polarization diversity, thus enhancing the flexibility and adaptability of the systems. Therefore, studying microwave devices with efficient linear polarization control capabilities is of great significance for promoting the progress of wireless communication technology.

[0003] Currently, electromagnetic metasurfaces have been widely used in the design of various polarization controllers due to their advantages such as low profile and easy processing in polarization control. According to the propagation direction of the outgoing electromagnetic waves, polarization control can be divided into two types: reflective and transmissive. Reflective polarization controllers are easy to achieve linear polarization control and produce high-performance operation because they have a metal reflector, but their feed sources will block the propagation of electromagnetic waves. Although the offset feeding method can solve the problem of feed source blocking, it will cause the problem of beam asymmetry. Different from reflective polarization controllers, transmissive polarization controllers can effectively avoid the feed source occlusion effect and show obvious advantages especially in beam scanning and beam control scenarios.

[0004] However, to achieve high-performance operation, transmissive polarization controllers mostly adopt the multi-layer stacking design method. Although this method is effective, it increases the complexity of the structural design. In addition, once the structure of a passive transmissive polarization controller is processed, its electromagnetic characteristics are fixed, resulting in a single function and inability to be adjusted.

[0005] Based on this, a reconfigurable broadband transmissive linear polarization controller is now provided, which can eliminate the drawbacks of existing polarization controllers. Summary of the Invention

[0006] The purpose of the present invention is to provide a reconfigurable broadband transmissive linear polarization controller to solve the problems of the modern products in the background art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A reconfigurable broadband transmissive linear polarization controller, comprising a polarization controller body, wherein a plurality of polarization control units are arranged in the polarization controller body, and the polarization controller body is formed by periodically arranging N*N polarization control units along the x and y directions;

[0009] The polarization control unit includes a top metal pattern, an intermediate dielectric substrate, a bottom metal pattern, and a PIN diode. The PIN diode is welded between the top metal pattern and the bottom metal pattern. The top metal pattern and the bottom metal pattern are connected through the intermediate dielectric substrate, and the top metal pattern and the bottom metal pattern are orthogonal to each other.

[0010] On the basis of the above technical solution, the present invention also provides the following optional technical solutions:

[0011] In an optional solution: The top metal pattern and the bottom metal pattern are etched from a copper foil with a thickness of 0.01–0.04 mm.

[0012] In an optional solution: The intermediate dielectric substrate uses an F4B board with a thickness h of 1.3–1.6 mm, a relative dielectric constant of 2.2–4.4, and a loss tangent of 0.001–0.002 as a support material, and the overall size is between 10 mm×10 mm×1.3 mm and 10 mm×10 mm×1.6 mm.

[0013] In an optional solution: The top metal pattern and the bottom metal pattern are connected by an asymmetric metal through-hole with a diameter of 0.4–0.6 mm.

[0014] In an optional solution: The top metal pattern and the bottom metal pattern are both etched with an intermediate gap with a width of 1.4–1.6 mm.

[0015] In an optional solution: The top metal pattern and the bottom metal pattern are both etched with an edge gap with a width of 0.24–0.27 mm.

[0016] In an optional solution: The top metal pattern and the bottom metal pattern are both etched with an E-shaped gap with a width of 1.4–1.6 mm.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention is small in size, simple in structure and convenient for production, achieving the regulation effect of x-polarized incident wave to y-polarized transmitted wave. By controlling the working state of PIN diodes, the line-line polarization regulation can be switched between low-frequency and high-frequency modes, and the angular stability is as high as 45°. Compared with other invention designs, the present invention exhibits the dual functions of simultaneous polarization regulation and frequency reconstruction, and has the advantages of broadband, high efficiency, low loss and high angular stability, and has broad application potential in fields such as controllable adaptive spatial filters, radar radomes and secure communication systems. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the present invention.

[0020] Figure 2 It is a top view of the present invention.

[0021] Figure 3 It is a bottom view of the present invention.

[0022] Figure 4 It is the first simulation result diagram of the reflection coefficient and transmission coefficient of the polarization regulator of the present invention.

[0023] Figure 5 It is the second simulation result diagram of the reflection coefficient and transmission coefficient of the polarization regulator of the present invention.

[0024] Figure 6 It is the unit structure evolution diagram of the polarization regulator of the present invention.

[0025] Figure 7 It is the first simulation result diagram of the unit structure evolution of the regulator of the present invention.

[0026] Figure 8 It is the second simulation result diagram of the unit structure evolution of the regulator of the present invention.

[0027] Figure 9 It is the first surface current distribution diagram of the polarization regulator of the present invention.

[0028] Figure 10 It is the second surface current distribution diagram of the polarization regulator of the present invention.

[0029] Figure 11 It is the first analysis diagram of the oblique incidence performance of the polarization regulator of the present invention in the PIN diode cut-off state.

[0030] Figure 12 It is the second analysis diagram of the oblique incidence performance of the polarization regulator of the present invention in the PIN diode cut-off state.

[0031] Figure 13 It is the first analysis diagram of the oblique incidence performance of the polarization regulator of the present invention in the PIN diode on state.

[0032] Figure 14 This is the second analysis diagram of the oblique incidence performance of the polarization regulator of the present invention in the conducting state of the PIN diode.

[0033] Figure 15 This is the performance comparison diagram of two polarization regulation structures of the polarization regulator of the present invention in the low-frequency working mode.

[0034] Figure 16 This is the performance comparison diagram of two polarization regulation structures of the polarization regulator of the present invention in the high-frequency working mode.

[0035] Annotation of reference numerals: 1 top-layer metal pattern, 2 intermediate dielectric substrate, 3 bottom-layer metal pattern, 4 asymmetric metal via, 5 intermediate gap, 6 PIN diode, 7 E-shaped gap, 8 edge gap. Detailed implementation manners

[0036] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0037] In one embodiment, as Figures 1-16 shown, a reconfigurable broadband transmissive linear polarization regulator includes a polarization regulator body, and a plurality of polarization regulation units are arranged in the polarization regulator body. The polarization regulator body is formed by periodically arranging N*N polarization regulation units along the x and y directions;

[0038] The polarization regulation unit includes a top-layer metal pattern 1, an intermediate dielectric substrate 2, a bottom-layer metal pattern 3, and a PIN diode 6. The PIN diode 6 is welded between the top-layer metal pattern 1 and the bottom-layer metal pattern 3. The top-layer metal pattern 1 and the bottom-layer metal pattern 3 are connected through the intermediate dielectric substrate 2, and the top-layer metal pattern 1 and the bottom-layer metal pattern 3 are orthogonal to each other.

[0039] The multifunctional reconfigurable transmissive linear polarization regulator forms a polarization regulation unit with chiral characteristics through the ingenious design of the top-layer metal pattern 1, the bottom-layer metal pattern 3, and the asymmetric metal via 4, and the support of the intermediate dielectric substrate 2. When an incident linearly polarized wave passes through this polarization regulator, it will be affected by the chiral structure and interact with it, resulting in a change in the polarization state of the electromagnetic wave. By changing the switching state of the PIN diode 6, the electromagnetic coupling between the top-layer metal pattern 1 and the bottom-layer metal pattern 3 can be dynamically adjusted, the electric field (current) distribution between the two layers can be changed, and thus the polarization direction and working mode of the transmitted electromagnetic wave can be regulated.

[0040] In one embodiment, the top-layer metal pattern 1 and the bottom-layer metal pattern 3 are etched from a copper foil with a thickness of 0.01–0.04 mm. Its conductivity is the same as that of gold and silver.

[0041] In one embodiment, the intermediate dielectric substrate 2 uses F4B board with a thickness h of 1.3–1.6 mm, a relative dielectric constant of 2.2–4.4, and a loss tangent of 0.001–0.002 as the support material, and the overall size ranges from 10 mm×10 mm×1.3 mm to 10 mm×10 mm×1.6 mm.

[0042] In one embodiment, the top metal pattern 1 and the bottom metal pattern 3 are connected by an asymmetric metal via 4 with a diameter of 0.4–0.6 mm to form a chiral structure and achieve broadband line-to-line polarization control.

[0043] In one embodiment, both the top metal pattern 1 and the bottom metal pattern 3 are etched with an intermediate slit 5 with a width of 1.4–1.6 mm to distinguish the positive and negative poles of the PIN diode and reduce the design of the additional feeding network.

[0044] In one embodiment, both the top metal pattern 1 and the bottom metal pattern 3 are etched with an edge slit 8 with a width of 0.24–0.27 mm to embed a capacitor as a DC blocker and achieve independent control of each layer of PIN diodes.

[0045] In one embodiment, both the top metal pattern 1 and the bottom metal pattern 3 are etched with an E-shaped slit 7 with a width of 1.4–1.6 mm.

[0046] It is used to improve the angular stability of polarization control.

[0047] The above embodiments disclose a reconfigurable broadband transmissive linear polarization controller, and its specific working principle is as follows:

[0048] By changing the working state of the PIN diode, the polarization controller can freely switch between two working modes of low frequency and high frequency, and each working mode has the functions of broadband line-to-line polarization control and frequency selection. According to the orthogonal E-shaped slit design, the angular stability of the two working modes is as high as 45°. The present invention has only a single-layer dielectric substrate, a streamlined PIN diode configuration, no additional feeding network design, and has the advantages of low loss, broadband, high efficiency, and high angular stability.

[0049] Among them, the top metal pattern 1 and the bottom metal pattern 3 are orthogonal to each other to control the transmission direction of electromagnetic waves;

[0050] The combination of the top metal pattern 1 and the bottom metal pattern 3 and the intermediate dielectric substrate 2 forms a resonance for the incident electromagnetic wave;

[0051] The top metal pattern 1 and the bottom metal pattern 3 are embedded with PIN diodes 6 to change the current flow path and induce resonances in different frequency bands.

[0052] The PIN diode 6 is selected as the SMP1321-079LF model produced by Skyworks, which has low insertion loss and stable electronic characteristics;

[0053] The present invention has the dual functions of polarization regulation and frequency reconfiguration. By controlling the working state of the PIN diode 6, the working frequency band of the line-line polarization regulation can be adjusted.

[0054] The present invention has two working modes: low frequency and high frequency, and each mode can achieve broadband line-line polarization regulation and frequency selection functions.

[0055] The multifunctional reconfigurable transmissive linear polarization regulator forms a polarization regulation unit with chiral characteristics through the ingenious design of the top metal pattern 1, the bottom metal pattern 3 and the asymmetric metal vias 4, and the support of the intermediate dielectric substrate 2. When an incident linearly polarized wave passes through the polarization regulator, it will be affected by the chiral structure and interact with it, resulting in a change in the polarization state of the electromagnetic wave. By changing the switching state of the PIN diode 6, the electromagnetic coupling between the top metal pattern 1 and the bottom metal pattern 3 can be dynamically adjusted, changing the electric field (current) distribution between the two layers, and further realizing the regulation of the polarization direction and working mode of the transmitted electromagnetic wave.

[0056] The polarization conversion ratio (PCR) is a key index to measure the degree of linear polarization rotation. When the electromagnetic wave is incident with x polarization, for the transmission model, the calculation formula of the polarization conversion efficiency PCR is:

[0057]

[0058] For the x-polarized vertically incident wave, when a reverse bias voltage is applied, the PIN diode is in the cut-off state. At this time, the polarization regulator works in the low-frequency mode, as Figure 4 shown. In the whole frequency band, the magnitudes of the reflection coefficient r yx and the transmission coefficient t xx are close to 0, and almost no cross-polarization reflection component and co-polarization transmission component are generated. And in the frequency range of 7.67 - 10.51 GHz, the cross-polarization transmission coefficient t yxThe amplitude increases significantly and all remain above 0.9. This phenomenon indicates that after passing through the polarization regulation structure, the x-polarized incident wave is effectively converted into a y-polarized transmitted wave. Since the reflection coefficient is within this frequency band, its amplitude value is relatively small; once outside this frequency band, its amplitude value is relatively large. Therefore, in the frequency range of 7.67 - 10.51 GHz, the transmission polarization regulation structure not only achieves an efficient line-line polarization regulation effect but also exhibits good operating frequency selection characteristics.

[0059] As Figure 5 shown, when a positive bias voltage is applied, the PIN diode 6 enters the conducting state, and at this time, the polarization regulator operates in the high-frequency mode. At the center frequency point of 11.15 GHz, the cross-polarization transmission coefficient t yx forms an obvious transmission passband. In addition, for the co-polarization transmission coefficient t xx , it still maintains a very low amplitude value within the frequency band, while for the co-polarization reflection coefficient r xx , it can obtain a relatively large amplitude value outside the frequency band, thus generating a strong reflection effect. Therefore, by controlling the operating state of the PIN diode, the polarization regulation structure can operate in different frequency bands, thus achieving the dual effects of polarization regulation and frequency reconfiguration.

[0060] As Figure 6 shows, three different polarization regulation structures are presented, namely Case 1, Case 2, and Case 3. As Figure 6 shown, by comparing the simulation results of Case 1 and Case 2, it can be found that the design of the metal through-hole plays a key role in the structure's realization of polarization regulation, determining the transition from linear polarization to its orthogonal polarization state. Further, by comparing the simulation results of Case 2 and Case 3, it can be seen that introducing orthogonal rectangular slots can significantly improve the amplitude of the transmission coefficient t yx and reduce the amplitude of the reflection coefficient r xx .

[0061] To explain the physical mechanism of line-line polarization regulation and frequency reconfiguration, the top layer of the polarization regulator is regarded as the receiving layer of electromagnetic waves, and the bottom layer is regarded as the transmission layer of electromagnetic waves to analyze the energy coupling relationship between the two layers. When the x-polarized wave is incident vertically, at the center frequency points of 9.22 GHz and 11.15 GHz, the surface current distribution of the polarization regulation structure;

[0062] As Figure 9 and 10As shown in the figure. The current on the top metal surface is mainly concentrated in the peripheral areas of the slit and the edges of the rectangular groove, and flows into the bottom layer through metal vias, generating an induced current in the y direction. It can be observed that the intensity of the induced current is relatively large in the peripheral area of the metal hole. Such a phenomenon reveals a high correlation between line-line polarization regulation and metal vias. From the perspective of the geometric structure, the embedding of metal vias makes the structure exhibit mirror asymmetry characteristics, thus generating a linear polarization rotation effect. It can be found that when the PIN diode 6 operates in different states, the overall current flow direction remains basically unchanged, but the path changes. For this reason, by changing the operating state of the PIN diode 6, the polarization regulation structure can simultaneously achieve the functions of polarization regulation and frequency reconfiguration.

[0063] As Figure 11 shown, when the PIN diode is in the cut-off state, as the incident angle θ increases from 0° to 45°, the cross-polarization transmission coefficient t yx curve shifts towards the high-frequency region, and in the middle region of the frequency band, the ripple amplitude increases significantly. This is because under the incidence of the x-polarized wave, the operating bandwidth is negatively correlated with 1 / cosθ. Obviously, as the incident angle θ increases, the line-line polarization regulation performance deteriorates. As Figure 12 shown, adding an orthogonal rectangular groove to the structure can further improve the cross-polarization transmission coefficient t yx amplitude and frequency offset. Especially when the incident angle θ = 45°, at the center frequency of 10.08 GHz, the amplitude of the cross-polarization transmission coefficient t yx increases from -1.34 dB (Case 2) to -1.21 dB (Case 3). As Figure 13 and 14 shown, when the PIN diode is in the on state, in the high-frequency operating mode, this similar phenomenon is more obvious, demonstrating the significant role of the orthogonal rectangular groove in improving the angle stability.

[0064] As Figure 15 and 16The figure shows the performance comparison of two polarization regulation structures, Case 2 and Case 3, at different incident angles. From the data in the table, it can be seen that when the incident angle is fixed, adding the orthogonal rectangular groove design not only reduces the frequency deviation of the transmitted wave, but also further optimizes the polarization conversion efficiency (PCR) in the intermediate frequency band and reduces the insertion loss in the entire frequency band. For example, for a 45° oblique incidence, when the PIN diode is in the cut-off state, in the frequency range of 8.35 - 11.73 GHz, this polarization regulator can convert the x-polarized incident wave into a y-polarized transmitted wave with a polarization conversion efficiency (PCR) greater than 0.87, and the insertion loss in the frequency band is less than 1.23 dB; when the PIN diode is in the on state, it is converted into a y-polarized transmitted wave with a PCR greater than 0.82, and the insertion loss in the corresponding frequency band is less than 1.72 dB. Obviously, under the action of the orthogonal rectangular groove, even for a 45° incidence, the polarization regulator can still exhibit efficient and broadband linear-linear polarization regulation performance.

[0065] Analysis of the simulation results shows that when an x-polarized wave is incident, in the frequency ranges of 7.67 - 10.51 GHz and 10.35 - 12.25 GHz, the polarization regulation structure can achieve efficient and broadband conversion from x-polarized wave to y-polarized transmitted wave, and the angular stability is as high as 45°. By controlling the working state of the PIN diode, the low-frequency and high-frequency working modes can be freely switched. In summary, this design has broad application prospects in controllable and adaptive spatial filters, radar radomes, and secure communication systems.

[0066] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A reconfigurable broadband transmission type linear polarization controller, characterized in that: It comprises a polarization regulator body, wherein a plurality of polarization regulation units are arranged in the polarization regulator body, and the polarization regulator body is formed by N*N polarization regulation units periodically arranged along the x and y directions; The polarization control unit comprises a top metal pattern (1), an intermediate dielectric substrate (2), a bottom metal pattern (3), and a PIN diode (6); a PIN diode (6) is welded between the top metal pattern (1) and the bottom metal pattern (3); the top metal pattern (1) and the bottom metal pattern (3) are connected via the intermediate dielectric substrate (2); and the top metal pattern (1) and the bottom metal pattern (3) are orthogonal to each other.

2. The reconfigurable broadband transmission type linear polarization controller according to claim 1, characterized in that: The top metal pattern (1) and the bottom metal pattern (3) are formed by etching a metal copper foil with a thickness of 0.01-0.04 mm.

3. The reconfigurable broadband transmission type linear polarization controller according to claim 1, characterized in that: The intermediate dielectric substrate (2) uses an F4B plate with a thickness h of 1.3-1.6 mm, a relative dielectric constant of 2.2-4.4, and a loss tangent of 0.001-0.002 as a supporting material, and the overall size is between 10 mm×10 mm×1.3 mm and 10 mm×10 mm×1.6 mm.

4. The reconfigurable broadband transmission type linear polarization controller according to claim 1, characterized in that: The top metal pattern (1) and the bottom metal pattern (3) are connected by an asymmetric metal through hole (4) with a diameter of 0.4-0.6 mm.

5. The reconfigurable broadband transmission type linear polarization controller according to claim 1, characterized in that: The gold top metal pattern (1) and the bottom metal pattern (3) are both etched with a middle gap (5) with a width of 1.4-1.6 mm.

6. The reconfigurable broadband transmission type linear polarization controller according to claim 1, characterized in that: The top metal pattern (1) and the bottom metal pattern (3) are both etched with edge gaps (8) with a width of 0.24-0.27 mm.

7. The reconfigurable broadband transmission type linear polarization controller according to claim 1, characterized in that: Both the top metal pattern (1) and the bottom metal pattern (3) are etched with an E-shaped gap (7) with a width of 1.4-1.6 mm.

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