Active regulation broadband wave-transparent FSS material

Abstract

The invention belongs to the technical field of electromagnetic wave control, and particularly relates to an active regulation broadband wave-transparent FSS material. According to the invention, a three-layer structure is adopted, through the design of the patterned upper metal layer and the patterned lower metal layer, the eight variable capacitance diodes are supplemented, and the capacitance values of the variable capacitance diodes are adjusted, so that the simultaneous active tuning of the high bandwidth range of double passbands is realized, and both the passband 1 and the passband 2 have the broadband regulation and control range. The regulation and control range of the first transmission passband is 3.8 GHz to 7.3 GHz, and the controllable relative bandwidth range is 63.1%; the regulation and control range of the second transmission passband is 8.5 GHz to 12.0 GHz, and the controllable relative bandwidth range is 34.15%; the maximum insertion loss of the two passbands is 2.5 dB, the two transmission passbands can be regulated and controlled at the same time, more application scenes are met, and TE and TM polarization is not sensitive. The excellent active bandwidth regulation and control performance can be suitable for the multi-frequency communication requirements of various agile radar radomes.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic wave control, and in particular relates to an actively regulated broadband wave-transmitting FSS material. Background Art

[0002] Frequency selective surfaces (FSS) are widely used in radomes, wireless communications, and signal propagation control. Traditional FSS can only provide fixed frequency bands, while adjustable multi-band FSS has gradually attracted attention due to its frequency band flexibility. However, the control range of multi-bands in existing active FSS is insufficient, and it cannot cover a wide range of frequency band requirements, and it cannot achieve simultaneous tuning of multiple bands, which limits its application in complex communication systems. Therefore, it is of great significance to develop an FSS that can achieve broadband wave transmission and simultaneous multi-band control. Summary of the invention

[0003] In view of the above problems or shortcomings, in order to solve the problem that the existing frequency selective surface FSS has an insufficient control range in multiple frequency bands and cannot achieve simultaneous tuning of multiple frequency bands, which limits its application in complex communication systems, the present invention provides an actively controlled broadband wave-transparent FSS material to achieve broadband control in multiple bands. The specific contents of the present invention are as follows:

[0004] An actively regulated broadband wave-transmitting FSS material is composed of structural units arranged in a matrix in a tight periodic manner. The structural unit is a square with a period of P. The structural unit includes a three-layer structure of a first metal layer A, an intermediate dielectric layer and a second metal layer B stacked in sequence from top to bottom.

[0005] The intermediate dielectric layer is a square dielectric layer with a side length of P (ie, the range of the structural unit period P), a metal through hole is arranged at the center, and metal through holes are arranged at the four corners with the vertices as the centers.

[0006] The first metal layer A includes: an equilateral right-angled triangle metal patch, a metal ring, a rectangular patch, a sun-shaped metal patch and a varactor diode.

[0007] There are 4 equilateral right-angled triangle metal patches in total and they are identical, and are distributed on the four corners of the dielectric layer in the middle of the structural unit with their two right-angled sides adaptively aligned with one corner of the structural unit.

[0008] The metal ring is an irregular ring: a ring is constructed with the center of the square as the center, the outer ring of the ring intersects with the four sides of the square and the inner ring does not intersect, and the intersecting part of the outer ring is not counted; the corresponding ring area between the two points where one corner of the square intersects with the outer ring of the ring (that is, the ring area opposite to the equilateral right triangle metal patch) is replaced in the center with a rectangular metal strip with the same width as the ring, and the four corners of the square are replaced with four rectangular metal strips accordingly, and the rectangular metal strips do not touch the sides of the square or the base of the equilateral right triangle.

[0009] The rectangular patches are arranged in a one-to-one correspondence toward the center of the circle in a manner that their long sides overlap with the inner long sides of the rectangular metal strips in the center, with a total of 4.

[0010] The sun-shaped metal patch is formed by setting 8 identical rectangular grooves at equal intervals on the outer edge of a circular metal patch. The extended lines of the midlines of the two short sides of the rectangular grooves pass through the center of the circle. The sun-shaped metal patch is centrally set on the middle dielectric layer and does not intersect with the rectangular patch.

[0011] The four gaps between the metal ring and the equilateral right-angled triangle metal patch are all connected with variable capacitance diodes in the middle along the diagonal correspondingly; the four gaps between the rectangular patch and the sun-shaped metal patch are also connected with variable capacitance diodes in the middle along the diagonal correspondingly.

[0012] The second metal layer B is composed of three metal wire grids (feeder grids) distributed in parallel and two fixed resistors arranged on each metal wire grid. The three metal wire grids are of the same length as P, and the six fixed resistors have the same resistance value. Relative to the square of the intermediate dielectric layer, the middle metal wire grid is centered and parallel to one side of the square and attached to the bottom of the square. The other two metal wire grids are arranged to overlap with the parallel sides corresponding to the square relative to the middle metal wire grid.

[0013] The middle metal wire grid is connected to the sun-shaped metal patch through the central metal through hole of the middle dielectric layer, and the two ends of the two metal wire grids on both sides are connected to four equilateral right-angled triangle metal patches through the metal through holes at the four corners of the middle dielectric layer.

[0014] When the structural units are arranged in a tight periodic matrix, the equilateral right-angled triangle metal patches, metal rings and squares of adjacent structural units are connected at their intersecting edges, and the metal wire grids between adjacent structural units in the direction of the middle metal wire grid are extended and connected, and the adjacent structural units in the direction perpendicular to the middle metal wire grid are adaptively spliced ​​and connected with the metal wire grids on both sides.

[0015] Furthermore, the metal through holes at the four corner vertices of the intermediate dielectric layer are 1 / 4 of the central metal through hole (equally divided into 4 with the center of the circle as the midpoint), so that all the metal through holes arranged in the array have the same radius, which is easy to manufacture by industrial process.

[0016] Furthermore, the width of the middle metal wire grid is twice that of the other two metal wire grids, so that the overall material performance after the periodic arrangement is better.

[0017] Further, according to the capacitance range of the varactor diodes: the four varactor diodes between the metal ring and the equilateral right triangle metal patch are regulated to achieve the tuning of channel 2; or, the four varactor diodes between the rectangular patch and the sun-shaped metal patch are regulated to achieve the tuning of channel 1; or, the capacitance values ​​of all eight varactor diodes are regulated at the same time to achieve simultaneous tuning of the bandwidths of passband 1 and passband 2.

[0018] Furthermore, the structural unit P=7 mm, and the thickness of the two metal layers is 0.035 mm.

[0019] In summary, the present invention adopts a three-layer structure, through the graphic upper and lower metal layer design, supplemented by 8 varactor diodes, by adjusting the capacitance of the varactor diodes, the high bandwidth range of the dual passbands can be actively tuned at the same time, and both passband 1 and passband 2 have a broadband control range. The first transmission passband control range is 3.8GHz~7.3GHz, and the controllable relative bandwidth range is 63.1%; the second transmission passband control range is 8.5GHz~12.0GHz, and the controllable relative bandwidth range is 34.15%; the maximum insertion loss of the two passbands is 2.5dB, and the transmittance exceeds 50%. The two transmission passbands can be adjusted simultaneously to meet more application scenarios, and are insensitive to TE and TM polarizations. Its excellent active bandwidth control performance can be applied to the multi-frequency communication needs of various agile radar antenna covers. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of the first metal layer A in the embodiment;

[0021] Figure 2 is an enlarged schematic diagram of the first metal layer A of the structural unit of the embodiment;

[0022] Figure 3 is an enlarged schematic diagram of the second metal layer B of the structural unit of the embodiment;

[0023] Figure 4 is a structural perspective view of a structural unit of an embodiment;

[0024] Figure 5 Schematic diagram of the transmission coefficient of the example sample under TE and TM polarization. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0026] An actively regulated broadband wave-transmitting FSS material: the structural units are arranged in a matrix in a tight periodic manner, the structural unit is a square with a period of P, and the structural unit includes a three-layer structure of a first metal layer A, an intermediate dielectric layer and a second metal layer B stacked in sequence from top to bottom.

[0027] In this embodiment, the enlarged schematic diagram of the first metal layer A of the structural unit is as follows: Figure 2 As shown:

[0028] The middle dielectric layer is a square dielectric with a side length of P = 7 mm (such as Figure 4 As shown in the figure, a metal through hole Q0 is provided at the center, and four 1 / 4 metal through holes (Q1, Q2, Q3, Q4) are provided at the four corners with the vertex as the center, and the radius of all metal through holes is the same.

[0029] The first metal layer A includes: an equilateral right-angled triangle metal patch, a metal ring (A10), a rectangular patch, a sun-shaped metal patch (A30) and a varactor diode.

[0030] Four equilateral right-angled triangle metal patches (A00, A01, A02, A03) are distributed on the four corners of the dielectric layer in the middle of the structural unit with their two right-angled sides adaptively aligned with one corner of the structural unit.

[0031] The metal ring (A10) is an irregular ring: a ring is constructed with the center of the square as the center, the outer ring of the ring intersects with the four sides of the square and the inner ring does not intersect, and the intersecting part of the outer ring is not counted; the corresponding ring area between two points where one corner of the square intersects with the outer ring of the ring (that is, the ring area opposite to the equilateral right triangle metal patch) is replaced in the center with a rectangular metal strip (D1, D2, D3, D4) with the same width as the ring, and four rectangular metal strips are replaced correspondingly at the four corners, and the rectangular metal strips do not touch the sides of the square or the base of the equilateral right triangle.

[0032] The rectangular patches (A20, A21, A22, A23) are arranged in a one-to-one correspondence toward the center of the circle in a manner that their long sides overlap with the inner long side of a rectangular metal strip, and there are 4 of them in total.

[0033] The sun-shaped metal patch (A30) is formed by arranging 8 identical rectangular grooves (A40, A41, A42, A43, A44, A45, A46, A47) at equal intervals on the outer edge of a circular metal patch, and the extended lines of the midlines of the two short sides of the rectangular grooves pass through the center of the circle. The sun-shaped metal patch is centrally arranged on the intermediate dielectric layer and does not intersect with the rectangular patch.

[0034] The four gaps between the metal ring (A10) and the equilateral right-angled triangle metal patches (A00, A01, A02, A03) are all connected along the diagonal lines and are respectively provided with variable capacitance diodes (C00, C01, C02, C03); the four gaps between the rectangular patches (A20, A21, A22, A23) and the sun-shaped metal patch (A30) are also all connected along the diagonal lines and are respectively provided with variable capacitance diodes (C10, C20, C30, C40).

[0035] The second metal layer B is composed of three parallel distributed metal wire grids (B00, B01, B02) and two fixed resistors (R1, R2, R3, R4, R5, R6) arranged on each metal wire grid; relative to the square of the intermediate dielectric layer, the middle metal wire grid (B01) is centrally attached with a side parallel to the square and is arranged below the square; the other two metal wire grids (B00, B02) are arranged to overlap with the parallel sides corresponding to the square relative to the middle metal wire grid, and their widths are both 1 / 2 of the middle metal wire grid.

[0036] In this embodiment: P = 7mm, the length of the right angle side of the equilateral right triangle metal patch is 1.62mm; the metal ring A10 is concentric with the structural unit, the outer diameter of the ring is 3.6mm, and the inner diameter is 3.25mm; the varactor diode is MA46H120; the rectangular patches are arranged in pairs along the two diagonals of the unit, and the long sides of the rectangular patches are arranged from the metal ring A10 to the center of the unit, showing rotational symmetry. The length of the rectangular patch is 0.92mm and the width is 1.5mm; the radius of the circle to which the sun-shaped metal patch A30 belongs is 1.9mm, and the length of the rectangular groove is 0.78mm and the width is 0.52mm. The thickness of the two metal layers is 0.035mm; the dielectric constant of the intermediate dielectric layer is Rogers 4350B material with a loss tangent of 0.028 and a thickness of 1mm.

[0037] The array of actively regulated broadband wave-transmitting FSS materials can be composed of several structural units arranged periodically in the longitudinal and transverse directions. In the first metal layer A of adjacent units, electrical continuity is formed between the triangular patches and electrical continuity is formed between the metal rings. Figure 1 Schematic diagram of the overall structure of the first metal layer A after (8×8) matrix arrangement in this embodiment.

[0038] The metal wire grid feed lines in the second metal layer B also achieve electrical continuity between adjacent cells. Figure 3 It is a bottom view (second metal layer B) of the structural unit. Wire grid B01 is located in the center of the unit, and wire grids B00 and B02 are located on both sides of the unit. Wire grid B00 is 7 mm long and 0.5 mm wide; wire grids B01 and B02 are 7 mm long and 0.25 mm wide.

[0039] like Figure 4The overall perspective view of the structural unit, the intermediate dielectric layer is provided with metal through holes Q0, Q1, Q2, Q3, Q4, with a radius of 0.2mm. The metal through hole Q0 is located in the center of the unit, connecting the center of the sun-shaped metal patch A30 and the wire grid B01. Q1, Q2, Q3, Q4 are 1 / 4 metal through holes, connecting the right-angled vertices of the equilateral right-angled triangle metal patch and the two ends of the wire grid B00 and B02. A fixed value resistor is set on each wire grid at 1.5mm from its two ends, and the resistance is 39KΩ, including R1, R2, R3, R4, R5, and R6.

[0040] In full-wave simulation, periodic boundary conditions are set in the x and y directions, RLC boundary conditions are set for the diodes, and floquet excitation is set in the z direction. Based on the capacitance range of the MA46H120 diode, the simulation capacitance range is selected as 0.12pF to 0.6pF. As the capacitance values ​​of the eight variable capacitance diodes change simultaneously, the simulated S21 curve is as follows: Figure 5 As shown, the control range of passband 1 is 3.8 GHz to 7.3 GHz, and the controllable relative bandwidth range is 63.1%. The control range of passband 2 is 8.5 GHz to 12.0 GHz, and the controllable relative bandwidth range is 34.15%. The two passbands can be tuned simultaneously.

[0041] It can be seen from the above embodiments that the actively regulated broadband wave-transparent FSS material provided by the present invention has an actively regulated broadband wave-transparent FSS with dual passbands. Passband 1 and passband 2 both have a broadband regulation range, and the maximum insertion loss of the passband is 2.5 dB. The two transmission passbands can be regulated simultaneously to meet more application scenarios. Its excellent actively regulated bandwidth performance can be applied to the multi-frequency communication requirements of various agile radar antenna covers.

Claims

1. An actively regulated broadband wave-transmitting FSS material, characterized in that: The structural units are arranged in a matrix in a tight periodic manner, the structural unit is a square with a period of P, and the structural unit includes a three-layer structure of a first metal layer A, an intermediate dielectric layer, and a second metal layer B stacked in sequence from top to bottom; The intermediate dielectric layer is a square dielectric with a side length of P, a metal through hole is provided at the center, and metal through holes are provided at the four corners with the vertex as the center; The first metal layer A includes: an equilateral right-angled triangle metal patch, a metal ring, a rectangular patch, a sun-shaped metal patch and a varactor diode; There are 4 equilateral right-angled triangle metal patches in total and they are identical, and are distributed on the four corners of the dielectric layer in the middle of the structural unit with their two right-angled sides adaptively aligned with one corner of the structural unit; The metal ring is an irregular ring: a ring is constructed with the center of the square as the center, the outer ring of the ring intersects with the four sides of the square and the inner ring does not intersect, and the intersecting part of the outer ring is not counted; the corresponding ring area between the two points where one corner of the square intersects with the outer ring of the ring is replaced in the middle with a rectangular metal strip with the same width as the ring, and the four corners of the square are replaced with four rectangular metal strips, and the rectangular metal strips do not touch the sides of the square or the base of the equilateral right triangle; The rectangular patches are arranged in a one-to-one correspondence, with their long sides overlapping the inner long sides of the rectangular metal strips, toward the center of the circle, for a total of 4; The sun-shaped metal patch is formed by setting 8 identical rectangular grooves at equal intervals on the outer edge of a circular metal patch, and the extended lines of the midlines of the two short sides of the rectangular grooves pass through the center of the circle. The sun-shaped metal patch is centrally set on the middle dielectric layer and does not intersect with the rectangular patch; The four gaps between the metal ring and the equilateral right-angled triangle metal patch are all connected in the middle along the diagonal line in a one-to-one correspondence and are provided with variable capacitance diodes; the four gaps between the rectangular patch and the sun-shaped metal patch are also all connected in the middle along the diagonal line in a one-to-one correspondence and are provided with variable capacitance diodes; The second metal layer B is composed of three parallel metal wire grids and two fixed resistors arranged on each metal wire grid. The three metal wire grids are of the same length as P, and the six fixed resistors have the same resistance value. With respect to the square of the intermediate dielectric layer, the middle metal wire grid is centered and parallel to one side of the square and attached to the bottom of the square. The other two metal wire grids are arranged to overlap with the parallel sides corresponding to the square relative to the middle metal wire grid. The middle metal wire grid is connected to the sun-shaped metal patch through the central metal through hole of the middle dielectric layer, and the two ends of the two metal wire grids on both sides are connected to the four equilateral right-angled triangle metal patches through the metal through holes at the four corners of the middle dielectric layer; When the structural units are arranged in a tight periodic matrix, the equilateral right-angled triangle metal patches, metal rings and squares of adjacent structural units are connected at their intersecting edges, and the metal wire grids between adjacent structural units in the direction of the middle metal wire grid are extended and connected, and the adjacent structural units in the direction perpendicular to the middle metal wire grid are adaptively spliced ​​and connected with the metal wire grids on both sides.

2. The actively regulated broadband wave-transmitting FSS material according to claim 1, characterized in that: The metal through holes at the four corner vertices of the intermediate dielectric layer are 1 / 4 of the central metal through hole, so that the radius of all the metal through holes arranged in the array is the same.

3. The actively regulated broadband wave-transmitting FSS material according to claim 1, characterized in that: The width of the middle metal wire grid is twice that of the other two metal wire grids.

4. The actively regulated broadband wave-transmitting FSS material according to claim 1, characterized in that: According to the capacitance range of the varactor diodes: the four varactor diodes between the metal ring and the equilateral right triangle metal patch are regulated to achieve the tuning of channel 2; or, the four varactor diodes between the rectangular patch and the sun-shaped metal patch are regulated to achieve the tuning of channel 1; or, the capacitance values ​​of all eight varactor diodes are regulated at the same time to achieve simultaneous tuning of the bandwidths of passband 1 and passband 2.

5. The actively regulated broadband wave-transmitting FSS material according to claim 1, characterized in that: The varactor diode is MA46H120.

6. The actively regulated broadband wave-transmitting FSS material according to claim 1, characterized in that: The structural unit P=7mm, and the thickness of the two metal layers is 0.035mm; the middle dielectric layer uses Rogers4350B material with a dielectric constant of 3.48 and a loss tangent of 0.028, and has a thickness of 1mm; the right-angled side of the equilateral right-angled triangle metal patch is 1.62mm; the outer diameter of the metal ring is 3.6mm, and the inner diameter is 3.25mm; the rectangular patch is 0.92mm long and 1.5mm wide; the radius of the circle to which the sun-shaped metal patch belongs is 1.9mm, and the rectangular groove is 0.78mm long and 0.52mm wide; the resistance of the 6 fixed resistors is 39KΩ, and they are set on each metal wire grid 1.5mm away from its two ends.

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