A multi-band pulse wave absorber based on a capacitive nonlinear circuit

Abstract

The application relates to a multi-band pulse wave absorber based on a capacitive nonlinear circuit. The technical scheme is as follows: the multi-band pulse wave absorber based on the capacitive nonlinear circuit is one of a double-band pulse wave absorber, a three-band pulse wave absorber and a four-band pulse wave absorber. The basic structure of the multi-band pulse wave absorber is composed of 2-4 resonance units, each of which is sequentially fixed by a front metal plate (2), a middle dielectric substrate (3) and a rear metal plate (4), and a circuit module (1) is arranged between the two 'concave' flat plates of the front metal plate (2). The application has the characteristics of simple structure, strong absorption to pulse waves, low absorption to continuous waves, high absorption to multi-band pulse waves and high absorption rate. The application is suitable for communication, radar and antenna fields.

Description

Technical Field

[0001] This invention pertains to multi-band pulse wave absorbers. Specifically, it relates to a multi-band pulse wave absorber based on a capacitive nonlinear circuit. Background Technology

[0002] Electromagnetic wave absorbers based on metasurfaces have become one of the current research hotspots. Among them, the research on the absorption performance of electromagnetic wave signals with specific waveforms (pulse widths) at the same frequency is mainly focused on single frequency. Therefore, the technical development and research of metasurface absorbers for electromagnetic signals with different pulse widths in multiple frequency bands has attracted the attention of those skilled in the art.

[0003] Wakatsuchi (Wakatsuchi H. Waveform-selective metasurfaces with free-space wave pulses at the same frequency[J]. Journal of Applied Physics, 2015, 117(16)) proposed a metasurface absorber with a nonlinear circuit from the perspective of waveform selection, which can selectively absorb microwave signals with different pulse widths at the same frequency. By reasonably designing the nonlinear circuit, it is possible to significantly distinguish between pulse waves and continuous waves of the same frequency, and it can also significantly distinguish between different waveforms (pulse widths) of various electromagnetic wave incident forms such as surface waves and free-space waves. This conclusion has been confirmed by microwave experiments. Although this type of nonlinear circuit metasurface structure is simple, passive, and does not require external voltage control, it has a narrow operating bandwidth and can only operate in a single frequency band, making it powerless to absorb the increasing number of multi-band pulse waves.

[0004] Yousaf et al. (Yousaf A, Murtaza M, Wakeel A, et al. A highly efficient low-profile tetra-band metasurface absorber for X, Ku, and K band applications[J]. AEU-International Journal of Electronics and Communications, 2022, 154: 154329) proposed a four-band metasurface absorber, which consists of three layers: a structural layer, a dielectric substrate isolation layer, and a grounded copper layer. The top structural layer includes a square split-ring resonator (SRR), four circular inscribed rings, and a central star design. The length of each ring intersects at 45° along the center, enabling strong signal absorption near four frequency points: 8.0 GHz, 13.1 GHz, 16.08 GHz, and 19.2 GHz. However, the drawback is its complex structure, which prevents strong absorption of pulse waves and low absorption of continuous waves at the same frequency.

[0005] Cheng et al. (Cheng Yongzhi, Qian Yingjie, Li Zhiren. Design of pulse wave metasurface absorber based on ring resonator integrated nonlinear circuit [J]. Journal of Electronics and Information Technology, 2023, 45(6): 1-9) studied a nonlinear circuit metasurface absorber that can selectively absorb specific pulse waves at the same frequency. The designed pulse wave metasurface absorber unit structure consists of a metal square ring resonator with integrated diode and resistor-capacitor parallel nonlinear circuit, an intermediate dielectric substrate isolation layer, and a bottom ground layer. Although the metasurface absorber has a high absorption rate for 50ns short pulse waves near 3.2GHz, its drawback is that it can only be applied to pulse wave absorption within a single frequency band. Summary of the Invention

[0006] The present invention aims to overcome the defects of the prior art and provides a multi-band pulse wave absorber based on a capacitive nonlinear circuit that is simple in structure, can achieve strong absorption of pulse waves and low absorption of continuous waves, and can absorb multi-band pulse waves with high absorption rate.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The multi-band pulse wave absorber is one of a dual-band pulse wave absorber, a tri-band pulse wave absorber, and a quad-band pulse wave absorber.

[0009] The basic structure of the dual-band pulse wave absorber consists of two resonant units, with the bottom of the first resonant unit and the top of the second resonant unit fixedly connected.

[0010] The basic structure of the three-band pulse wave absorber consists of three resonant units. The bottom of the first resonant unit is fixedly connected to the top of the second resonant unit, and the bottom of the second resonant unit is fixedly connected to the top of the third resonant unit.

[0011] The basic structure of the four-band pulse wave absorber consists of four resonant units. The bottom of the first resonant unit is fixedly connected to the top of the second resonant unit, the bottom of the second resonant unit is fixedly connected to the top of the third resonant unit, and the bottom of the third resonant unit is fixedly connected to the top of the fourth resonant unit.

[0012] The first resonant unit, the second resonant unit, the third resonant unit, and the fourth resonant unit are all composed of a front metal plate, an intermediate dielectric substrate, a rear metal plate, and a circuit module; the front side of the intermediate dielectric substrate of each resonant unit is fixedly connected to the rear side of the front metal plate, and the rear side of the intermediate dielectric substrate is fixedly connected to the front side of the rear metal plate.

[0013] In the resonant unit: both the rear metal plate and the intermediate dielectric substrate are square, and the four sides of the rear metal plate are flush with the four sides of the intermediate dielectric substrate, that is, the width B and height H of the resonant unit are equal; the front metal plate is composed of two concave plates, which are identical and symmetrically fixed to the left and right sides of the center line of the intermediate dielectric substrate. The openings of the two concave plates face outward, and the distance between the inner sides of the two concave plates is b0. The depth b of the concave opening of the concave plate is half of the height h of the concave opening; the circuit module is installed between the inner sides of the two concave plates and is located at the middle position of the center line.

[0014] The left and right sides of the front metal plate are flush with the left and right sides of the intermediate dielectric substrate; the height H0 of the front metal plate is 0.5 to 0.95 times the height H of the intermediate dielectric substrate, and the distance between the top and bottom sides of the front metal plate and the top and bottom sides of their respective intermediate dielectric substrates is equal.

[0015] The circuit module consists of a full-wave rectifier circuit, a capacitor C, and a resistor R. The four Schottky diodes in the full-wave rectifier circuit are, from left to right and from back to front, the first Schottky diode, the second Schottky diode, the third Schottky diode, and the fourth Schottky diode. The cathodes of the first and second Schottky diodes are connected together, and the anodes of the third and fourth Schottky diodes are connected together. One end of the capacitor C is connected to the cathode of the first Schottky diode, and the other end of the capacitor C is connected to the anode of the third Schottky diode. One end of the resistor R is connected to the cathode of the second Schottky diode, and the other end of the resistor R is connected to the anode of the fourth Schottky diode.

[0016] The anode of the first Schottky diode is connected to the inside of the left front metal plate, the anode of the second Schottky diode is connected to the inside of the right front metal plate, the cathode of the third Schottky diode is connected to the inside of the left front metal plate, and the cathode of the fourth Schottky diode is connected to the inside of the right front metal plate.

[0017] The front and rear metal plates are made of the same material, namely copper, aluminum, or silver.

[0018] The intermediate dielectric substrate is an insulating material with a relative permittivity of 1.0 to 20.0; the thickness of the intermediate dielectric substrate is t = 0.5 to 10 mm.

[0019] The dual-band pulse wave absorber:

[0020] The width B of the intermediate dielectric substrate and the rear metal plate is 5 to 100 mm;

[0021] The height h of the concave opening of the first resonant unit 21 =0.25~0.4B;

[0022] The height h of the concave opening of the second resonant unit 22 =0.6~0.75B;

[0023] Resistance R = 10kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF;

[0024] The Schottky diode is model number HSMS-286x series.

[0025] The three-band pulse wave absorber:

[0026] The width B of the intermediate dielectric substrate and the rear metal plate is 5 to 100 mm;

[0027] The height h of the concave opening of the first resonant unit 31 =0.6~0.75B;

[0028] The height h of the concave opening of the second resonant unit 32 =0.05~0.15B;

[0029] The height h of the concave opening of the third resonant unit 33 =0.45~0.55B;

[0030] Resistance R = 50kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF;

[0031] The Schottky diode is model number HSMS-286x series.

[0032] The four-band pulse wave absorber:

[0033] The width B of the intermediate dielectric substrate and the rear metal plate is 5 to 100 mm;

[0034] The height of the concave opening of the first resonant unit is 0.45~0.55B;

[0035] The height of the concave opening of the second resonant unit is 0.6~0.7B;

[0036] The height of the concave opening of the third resonant unit is 0.8 to 0.9B.

[0037] The height of the concave opening of the fourth resonant unit is 0.05~0.15B;

[0038] Resistance R = 500kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF;

[0039] The Schottky diode is model number HSMS-286x series.

[0040] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0041] (1) The basic structure of this invention consists of 2 to 4 resonant units. Each resonant unit is formed by fixing a front metal plate, an intermediate dielectric substrate, and a rear metal plate (4) in sequence. A circuit module is provided between the two concave plates of the front metal plate. The structure is simple and easy to manufacture. This invention does not require a power supply or external voltage control. It is suitable for communication systems with multiple frequency bands and can significantly improve the anti-interference capability of the communication system.

[0042] (2) By combining resonant units with different resonant frequencies and loading parallel resistors, capacitors and full-wave rectifier circuits on the resonant units, the present invention can achieve waveform selectivity effects of strong absorption of pulse waves and low absorption of continuous waves in multiple operating frequency bands.

[0043] (3) This invention employs nonlinear components and a reasonable circuit design. Under the premise of ensuring waveform selection performance, a nonlinear lumped circuit is introduced to influence the current on the metal surface, thereby realizing the perception of the incident electromagnetic wave duration. That is, the metasurface exhibits different absorption performance for incident signals with different pulse widths, effectively absorbing the energy of the pulse wave and converting it into heat energy. This helps protect other electronic devices from electromagnetic interference or electromagnetic radiation, achieving good multi-band pulse wave absorption performance.

[0044] The present invention fixes concave plates of similar shape but different size on the front side of the intermediate dielectric substrate, generating multiple different resonance points and achieving multi-band absorption effect. The pulse wave absorption rate of the dual-band pulse wave absorber is higher than 90%, the pulse wave absorption rate of the three-band pulse wave absorber is higher than 85%, and the pulse wave absorption rate of the four-band pulse wave absorber is higher than 80%.

[0045] Therefore, this invention features a simple structure, strong absorption of pulse waves and low absorption of continuous waves, and the ability to absorb multi-band pulse waves with high absorption rate. It is suitable for applications in communications, radar, and antennas. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the basic structure of the dual-band pulse wave absorber based on capacitive nonlinear circuits in this invention.

[0047] Figure 2 This is a schematic diagram of the basic structure of the three-band pulse wave absorber based on capacitive nonlinear circuits in this invention.

[0048] Figure 3 This is a schematic diagram of the basic structure of the four-band pulse wave absorber based on a capacitive nonlinear circuit in this invention.

[0049] Figure 4 for Figure 1 , Figure 2 , Figure 3 Schematic diagram of the structure of the middle resonant unit;

[0050] Figure 5 for Figure 4 A top view diagram;

[0051] Figure 6 for Figure 4 A magnified view of part of I;

[0052] Figure 7 The figure shows the simulation results of the absorption rate of the dual-band pulse wave absorber based on capacitive nonlinear circuit in this invention.

[0053] Figure 8 The figure shows the simulation results of the absorption rate of the three-band pulse wave absorber based on capacitive nonlinear circuit in this invention.

[0054] Figure 9 The figure shows the simulation results of the absorption rate of the four-band pulse wave absorber based on capacitive nonlinear circuit in this invention. Detailed Implementation

[0055] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments, and limitations on its scope of protection will be waived:

[0056] A multi-band pulse wave absorber based on a capacitive nonlinear circuit. In this specific embodiment, the multi-band pulse wave absorber is one of a dual-band pulse wave absorber, a tri-band pulse wave absorber, or a quad-band pulse wave absorber.

[0057] like Figure 1 As shown, the basic structure of the dual-band pulse wave absorber consists of two resonant units, with the bottom of the first resonant unit and the top of the second resonant unit fixedly connected.

[0058] like Figure 2 As shown, the basic structure of the three-band pulse wave absorber consists of three resonant units. The bottom of the first resonant unit is fixedly connected to the top of the second resonant unit, and the bottom of the second resonant unit and the top of the third resonant unit are fixedly connected.

[0059] like Figure 3 As shown, the basic structure of the four-band pulse wave absorber consists of four resonant units. The bottom of the first resonant unit is fixedly connected to the top of the second resonant unit, the bottom of the second resonant unit is fixedly connected to the top of the third resonant unit, and the bottom of the third resonant unit is fixedly connected to the top of the fourth resonant unit.

[0060] like Figure 4 and Figure 5 As shown, the first resonant unit, the second resonant unit, the third resonant unit and the fourth resonant unit are all composed of a front metal plate 2, an intermediate dielectric substrate 3, a rear metal plate 4 and a circuit module 1; the front side of the intermediate dielectric substrate 3 of each resonant unit is fixedly connected to the rear side of the front metal plate 2, and the rear side of the intermediate dielectric substrate 3 is fixedly connected to the front side of the rear metal plate 4.

[0061] like Figure 4 and Figure 5 As shown, in the resonant unit: both the rear metal plate 4 and the intermediate dielectric substrate 3 are square, and the four sides of the rear metal plate 4 are flush with the four sides of the intermediate dielectric substrate 3, that is, the width B and height H of the resonant unit are equal; the front metal plate 2 is composed of two concave plates, the two concave plates are identical, and the two concave plates are symmetrically fixed to the left and right sides of the center line of the intermediate dielectric substrate 3, the openings of the two concave plates face outward, the distance between the inner sides of the two concave plates is b0, and the depth b of the concave opening of the concave plate is half of the height h of the concave opening; the circuit module 1 is installed between the inner sides of the two concave plates, and the circuit module 1 is located at the middle position of the center line.

[0062] like Figure 4 and Figure 5As shown, the left and right sides of the front metal plate 2 are flush with the left and right sides of the intermediate dielectric substrate 3; the height H0 of the front metal plate 2 is 0.5 to 0.95 times the height H of the intermediate dielectric substrate 3, and the distance between the upper and lower sides of the front metal plate 2 and the upper and lower sides of the corresponding intermediate dielectric substrate 3 is equal.

[0063] like Figure 6 As shown, circuit module 1 consists of a full-wave rectifier circuit, capacitor C, and resistor R. The four Schottky diodes in the full-wave rectifier circuit are, from left to right and from back to front, the first Schottky diode, the second Schottky diode, the third Schottky diode, and the fourth Schottky diode. The cathodes of the first and second Schottky diodes are connected, and the anodes of the third and fourth Schottky diodes are connected. One end of capacitor C is connected to the cathode of the first Schottky diode, and the other end of capacitor C is connected to the anode of the third Schottky diode. One end of resistor R is connected to the cathode of the second Schottky diode, and the other end of resistor R is connected to the anode of the fourth Schottky diode.

[0064] like Figure 6 As shown, the anode of the first Schottky diode is connected to the inner side of the left front metal plate 2, the anode of the second Schottky diode is connected to the inner side of the right front metal plate 2, the cathode of the third Schottky diode is connected to the inner side of the left front metal plate 2, and the cathode of the fourth Schottky diode is connected to the inner side of the right front metal plate 2.

[0065] The front metal plate 2 and the rear metal plate 4 are made of the same material, namely copper, aluminum, or silver.

[0066] The intermediate dielectric substrate 3 is an insulating material with a relative permittivity of 1.0 to 20.0; the thickness of the intermediate dielectric substrate 3 is t = 0.5 to 10 mm.

[0067] The dual-band pulse wave absorber:

[0068] The width B of the intermediate dielectric substrate 3 and the rear metal plate 4 is 5 to 100 mm;

[0069] The height h of the concave opening of the first resonant unit 21 =0.25~0.4B;

[0070] The height h of the concave opening of the second resonant unit 22 =0.6~0.75B;

[0071] Resistance R = 10kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF;

[0072] The Schottky diode is model number HSMS-286x series.

[0073] The three-band pulse wave absorber:

[0074] The width B of the intermediate dielectric substrate 3 and the rear metal plate 4 is 5 to 100 mm;

[0075] The height h of the concave opening of the first resonant unit 31 =0.6~0.75B;

[0076] The height h of the concave opening of the second resonant unit 32 =0.05~0.15B;

[0077] The height h of the concave opening of the third resonant unit 33 =0.45~0.55B;

[0078] Resistance R = 50kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF;

[0079] The Schottky diode is model number HSMS-286x series.

[0080] The four-band pulse wave absorber:

[0081] The width B of the intermediate dielectric substrate 3 and the rear metal plate 4 is 5 to 100 mm;

[0082] The height of the concave opening of the first resonant unit is 0.45~0.55B;

[0083] The height of the concave opening of the second resonant unit is 0.6~0.7B;

[0084] The height of the concave opening of the third resonant unit is 0.8 to 0.9B.

[0085] The height of the concave opening of the fourth resonant unit is 0.05~0.15B;

[0086] Resistance R = 500kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF;

[0087] The Schottky diode is model number HSMS-286x series.

[0088] Example 1

[0089] A multi-band pulse wave absorber based on a capacitive nonlinear circuit. In this embodiment, the multi-band pulse wave absorber is a dual-band pulse wave absorber.

[0090] like Figure 1 As shown, the basic structure of the dual-band pulse wave absorber consists of two resonant units, with the bottom of the first resonant unit and the top of the second resonant unit fixedly connected.

[0091] like Figure 4 and Figure 5 As shown, both the first and second resonant units consist of a front metal plate 2, an intermediate dielectric substrate 3, a rear metal plate 4, and a circuit module 1. The front side of the intermediate dielectric substrate 3 of each resonant unit is fixedly connected to the rear side of the front metal plate 2, and the rear side of the intermediate dielectric substrate 3 is fixedly connected to the front side of the rear metal plate 4.

[0092] like Figure 4 and Figure 5 As shown, in the resonant unit: both the rear metal plate 4 and the intermediate dielectric substrate 3 are square, and the four sides of the rear metal plate 4 are flush with the four sides of the intermediate dielectric substrate 3, that is, the width B and height H of the resonant unit are equal; the front metal plate 2 is composed of two concave plates, the two concave plates are identical, and the two concave plates are symmetrically fixed to the left and right sides of the center line of the intermediate dielectric substrate 3, the openings of the two concave plates face outward, the distance between the inner sides of the two concave plates is b0, and the depth b of the concave opening of the concave plate is half of the height h of the concave opening; the circuit module 1 is installed between the inner sides of the two concave plates, and the circuit module 1 is located at the middle position of the center line.

[0093] like Figure 4 and Figure 5 As shown, the left and right sides of the front metal plate 2 are flush with the left and right sides of the intermediate dielectric substrate 3; the height H0 of the front metal plate 2 is 0.5 times the height H of the intermediate dielectric substrate 3, and the distance between the upper and lower sides of the front metal plate 2 and the upper and lower sides of their respective intermediate dielectric substrate 3 is equal.

[0094] In the first resonant unit and the second resonant unit:

[0095] The width B of the intermediate dielectric substrate 3 and the rear metal plate 4 is 17.5 mm;

[0096] Both the front metal plate 2 and the rear metal plate 4 are made of copper;

[0097] The intermediate dielectric substrate 3 is an insulating material with a relative permittivity of 2.0 and a thickness of t = 1.4 mm.

[0098] The concave opening of the first resonant unit: height h 21 =0.34B; depth b 21 =0.17B;

[0099] The concave opening of the second resonant unit: height h 22 =0.74B; depth b 22 =0.37B.

[0100] like Figure 6As shown, circuit module 1 consists of a full-wave rectifier circuit, capacitor C, and resistor R. The four Schottky diodes in the full-wave rectifier circuit are, from left to right and from back to front, the first Schottky diode, the second Schottky diode, the third Schottky diode, and the fourth Schottky diode. The cathodes of the first and second Schottky diodes are connected, and the anodes of the third and fourth Schottky diodes are connected. One end of capacitor C is connected to the cathode of the first Schottky diode, and the other end of capacitor C is connected to the anode of the third Schottky diode. One end of resistor R is connected to the cathode of the second Schottky diode, and the other end of resistor R is connected to the anode of the fourth Schottky diode.

[0101] like Figure 6 As shown, the anode of the first Schottky diode is connected to the inner side of the left front metal plate 2, the anode of the second Schottky diode is connected to the inner side of the right front metal plate 2, the cathode of the third Schottky diode is connected to the inner side of the left front metal plate 2, and the cathode of the fourth Schottky diode is connected to the inner side of the right front metal plate 2.

[0102] In this embodiment:

[0103] Resistance R = 50kΩ, capacitance C = 1nF;

[0104] The Schottky diode model is HSMS-2864.

[0105] This embodiment uses the commercial electromagnetic simulation software ANSYS Electronics Desktop to obtain the following simulation results. Figure 7 The simulation results of the absorption rate of the dual-band pulse wave absorber are shown in the figure. Figure 7 In the diagram, the horizontal axis represents frequency, and the vertical axis represents the percentage of absorbed electromagnetic wave energy relative to the total incident energy (i.e., absorption rate). Simulation results show that the absorption rate for 50ns pulse waves reaches over 90% within the range of 2GHz to 5GHz. Compared with existing technologies, this embodiment increases the operating frequency band while ensuring strong absorption of pulse wave signals and low absorption of continuous waves.

[0106] Example 2

[0107] A multi-band pulse wave absorber based on a capacitive nonlinear circuit. In this embodiment, the multi-band pulse wave absorber is a three-band pulse wave absorber.

[0108] like Figure 2 As shown, the basic structure of the three-band pulse wave absorber consists of three resonant units. The bottom of the first resonant unit is fixedly connected to the top of the second resonant unit, and the bottom of the second resonant unit and the top of the third resonant unit are fixedly connected.

[0109] like Figure 4 and Figure 5 As shown, the first resonant unit, the second resonant unit, and the third resonant unit are all composed of a front metal plate 2, an intermediate dielectric substrate 3, a rear metal plate 4, and a circuit module 1; the front side of the intermediate dielectric substrate 3 of each resonant unit is fixedly connected to the rear side of the front metal plate 2, and the rear side of the intermediate dielectric substrate 3 is fixedly connected to the front side of the rear metal plate 4.

[0110] like Figure 4 and Figure 5 As shown, in the resonant unit: both the rear metal plate 4 and the intermediate dielectric substrate 3 are square, and the four sides of the rear metal plate 4 are flush with the four sides of the intermediate dielectric substrate 3, that is, the width B and height H of the resonant unit are equal; the front metal plate 2 is composed of two concave plates, the two concave plates are identical, and the two concave plates are symmetrically fixed to the left and right sides of the center line of the intermediate dielectric substrate 3, the openings of the two concave plates face outward, the distance between the inner sides of the two concave plates is b0, and the depth b of the concave opening of the concave plate is half of the height h of the concave opening; the circuit module 1 is installed between the inner sides of the two concave plates, and the circuit module 1 is located at the middle position of the center line.

[0111] like Figure 4 and Figure 5 As shown, the left and right sides of the front metal plate 2 are flush with the left and right sides of the intermediate dielectric substrate 3; the height H0 of the front metal plate 2 is 0.7 times the height H of the intermediate dielectric substrate 3, and the distance between the upper and lower sides of the front metal plate 2 and the upper and lower sides of their respective intermediate dielectric substrates 3 is equal.

[0112] In the first resonant unit, the second resonant unit, and the third resonant unit:

[0113] The width B of the intermediate dielectric substrate 3 and the rear metal plate 4 is 18 mm;

[0114] Both the front metal plate 2 and the rear metal plate 4 are made of aluminum;

[0115] The intermediate dielectric substrate 3 is an insulating material with a relative permittivity of 3.0 and a thickness of t = 1.5 mm.

[0116] The concave opening of the first resonant unit: height h 31 =0.72B; depth b 31 =0.36B;

[0117] The concave opening of the second resonant unit: height h 32 =0.05B; depth b 32 =0.025B;

[0118] The concave opening of the third resonant unit: height h 33=0.5B; depth b 33 =0.25B.

[0119] like Figure 6 As shown, circuit module 1 consists of a full-wave rectifier circuit, capacitor C, and resistor R. The four Schottky diodes in the full-wave rectifier circuit are, from left to right and from back to front, the first Schottky diode, the second Schottky diode, the third Schottky diode, and the fourth Schottky diode. The cathodes of the first and second Schottky diodes are connected, and the anodes of the third and fourth Schottky diodes are connected. One end of capacitor C is connected to the cathode of the first Schottky diode, and the other end of capacitor C is connected to the anode of the third Schottky diode. One end of resistor R is connected to the cathode of the second Schottky diode, and the other end of resistor R is connected to the anode of the fourth Schottky diode.

[0120] like Figure 6 As shown, the anode of the first Schottky diode is connected to the inner side of the left front metal plate 2, the anode of the second Schottky diode is connected to the inner side of the right front metal plate 2, the cathode of the third Schottky diode is connected to the inner side of the left front metal plate 2, and the cathode of the fourth Schottky diode is connected to the inner side of the right front metal plate 2.

[0121] In this embodiment:

[0122] Resistance R = 500kΩ, capacitance C = 10nF;

[0123] The Schottky diode model is HSMS-2864.

[0124] This embodiment uses the commercial electromagnetic simulation software ANSYS Electronics Desktop to obtain the following simulation results. Figure 8 The simulation results of the absorption rate of the three-band pulse wave absorber are shown in the figure. Figure 8 In the diagram, the horizontal axis represents frequency, and the vertical axis represents the percentage of absorbed electromagnetic wave energy relative to the total incident energy (i.e., absorption rate). Simulation results show that the absorption rate for 50ns pulse waves reaches over 85% within the range of 2GHz to 5GHz. Compared with existing technologies, this embodiment increases the operating frequency band while ensuring strong absorption of pulse wave signals and low absorption of continuous waves.

[0125] Example 3

[0126] A multi-band pulse wave absorber based on a capacitive nonlinear circuit. In this embodiment, the multi-band pulse wave absorber is a four-band pulse wave absorber.

[0127] like Figure 3As shown, the basic structure of the four-band pulse wave absorber consists of four resonant units. The bottom of the first resonant unit is fixedly connected to the top of the second resonant unit, the bottom of the second resonant unit is fixedly connected to the top of the third resonant unit, and the bottom of the third resonant unit is fixedly connected to the top of the fourth resonant unit.

[0128] like Figure 4 and Figure 5 As shown, the first resonant unit, the second resonant unit, the third resonant unit, and the fourth resonant unit are all composed of a front metal plate 2, an intermediate dielectric substrate 3, a rear metal plate 4, and a circuit module 1. The front side of the intermediate dielectric substrate 3 of each resonant unit is fixedly connected to the rear side of the front metal plate 2, and the rear side of the intermediate dielectric substrate 3 is fixedly connected to the front side of the rear metal plate 4.

[0129] like Figure 4 and Figure 5 As shown, in the resonant unit: both the rear metal plate 4 and the intermediate dielectric substrate 3 are square, and the four sides of the rear metal plate 4 are flush with the four sides of the intermediate dielectric substrate 3, that is, the width B and height H of the resonant unit are equal; the front metal plate 2 is composed of two concave plates, the two concave plates are identical, and the two concave plates are symmetrically fixed to the left and right sides of the center line of the intermediate dielectric substrate 3, the openings of the two concave plates face outward, the distance between the inner sides of the two concave plates is b0, and the depth b of the concave opening of the concave plate is half of the height h of the concave opening; the circuit module 1 is installed between the inner sides of the two concave plates, and the circuit module 1 is located at the middle position of the center line.

[0130] like Figure 4 and Figure 5 As shown, the left and right sides of the front metal plate 2 are flush with the left and right sides of the intermediate dielectric substrate 3; the height H0 of the front metal plate 2 is 0.95 times the height H of the intermediate dielectric substrate 3, and the distance between the upper and lower sides of the front metal plate 2 and the upper and lower sides of their respective intermediate dielectric substrates 3 is equal.

[0131] In the first resonant unit, the second resonant unit, the third resonant unit, and the fourth resonant unit:

[0132] The width B of the intermediate dielectric substrate 3 and the rear metal plate 4 is 18.5 mm;

[0133] The front metal plate 2 and the rear metal plate 4 are made of the same material, both being silver; the intermediate dielectric substrate 3 is an insulating material with a relative permittivity of 4.0 and a thickness of t = 1.6 mm.

[0134] The concave opening of the first resonant unit: height h 41 =0.48B; depth b 41 =0.24B;

[0135] The concave opening of the second resonant unit: height h 42 =0.64B; depth b 42 =0.32B;

[0136] The concave opening of the third resonant unit: height h 43 =0.84B; depth b 43 =0.42B;

[0137] The concave opening of the fourth resonant unit: height h 44 =0.05B; depth b 44 =0.025B.

[0138] like Figure 6 As shown, circuit module 1 consists of a full-wave rectifier circuit, capacitor C, and resistor R. The four Schottky diodes in the full-wave rectifier circuit are, from left to right and from back to front, the first Schottky diode, the second Schottky diode, the third Schottky diode, and the fourth Schottky diode. The cathodes of the first and second Schottky diodes are connected together, and the anodes of the third and fourth Schottky diodes are connected together. One end of capacitor C is connected to the cathode of the first Schottky diode, and the other end of capacitor C is connected to the anode of the third Schottky diode. One end of resistor R is connected to the cathode of the second Schottky diode, and the other end of resistor R is connected to the anode of the fourth Schottky diode.

[0139] like Figure 6 As shown, the anode of the first Schottky diode is connected to the inner side of the left front metal plate 2, the anode of the second Schottky diode is connected to the inner side of the right front metal plate 2, the cathode of the third Schottky diode is connected to the inner side of the left front metal plate 2, and the cathode of the fourth Schottky diode is connected to the inner side of the right front metal plate 2.

[0140] In this embodiment:

[0141] Resistance R = 1MΩ, capacitance C = 100nF;

[0142] The Schottky diode model is HSMS-2864.

[0143] This embodiment uses the commercial electromagnetic simulation software ANSYS Electronics Desktop to obtain the following simulation results. Figure 9 The figure shown is a simulation result of the absorption rate of a four-band pulse wave absorber based on a capacitive nonlinear circuit. Figure 9In the diagram, the horizontal axis represents frequency, and the vertical axis represents the percentage of absorbed electromagnetic wave energy relative to the total incident energy (i.e., absorption rate). Simulation results show that the absorption rate for 50ns pulse waves reaches over 80% within the range of 2GHz to 5GHz. Compared with existing technologies, this embodiment increases the operating frequency band while ensuring strong absorption of pulse wave signals and low absorption of continuous waves.

[0144] This specific implementation method has the following advantages compared with the prior art:

[0145] (1) The basic structure of this specific embodiment consists of 2 to 4 resonant units. Each resonant unit is formed by fixing a front metal plate 2, an intermediate dielectric substrate 3, and a rear metal plate 4 in sequence. A circuit module 1 is provided between the two concave plates of the front metal plate 2. The structure is simple and easy to manufacture. This specific embodiment does not require a power supply or external voltage control, is suitable for communication systems with multiple frequency bands, and can significantly improve the anti-interference capability of the communication system.

[0146] (2) This specific embodiment combines resonant units with different resonant frequencies and loads parallel resistors, capacitors and full-wave rectifier circuits on the resonant units, which can achieve waveform selectivity effect of strong absorption of pulse waves and low absorption of continuous waves in multiple operating frequency bands.

[0147] (3) This specific embodiment employs nonlinear components and a reasonable circuit design. While ensuring waveform selection performance, a nonlinear lumped circuit is introduced to influence the surface current of the metal, achieving the perception of the incident electromagnetic wave's duration. That is, the metasurface exhibits different absorption properties for incident signals with different pulse widths, effectively absorbing the energy of the pulse wave and converting it into heat. This helps protect other electronic devices from electromagnetic interference or radiation, achieving excellent multi-band pulse wave absorption performance.

[0148] In this specific embodiment, "concave" flat plates of similar shape but different size are fixed on the front side of the intermediate dielectric substrate 3, generating multiple different resonance points and achieving the effect of multi-band absorption. The pulse wave absorption rate of the dual-band pulse wave absorber is higher than 90%, the pulse wave absorption rate of the three-band pulse wave absorber is higher than 85%, and the pulse wave absorption rate of the four-band pulse wave absorber is higher than 80%.

[0149] Therefore, this specific embodiment features a simple structure, strong absorption of pulse waves and low absorption of continuous waves, and the ability to absorb multi-band pulse waves with high absorption rate. It is suitable for applications in communications, radar, and antennas.

Claims

1. A multi-band pulse wave absorber based on a capacitive nonlinear circuit, characterized in that... The multi-band pulse wave absorber based on capacitive nonlinear circuit is one of a dual-band pulse wave absorber, a three-band pulse wave absorber, and a four-band pulse wave absorber. The basic structure of the dual-band pulse wave absorber consists of two resonant units, with the bottom of the first resonant unit and the top of the second resonant unit fixedly connected. The basic structure of the three-band pulse wave absorber consists of three resonant units. The bottom of the first resonant unit is fixedly connected to the top of the second resonant unit, and the bottom of the second resonant unit is fixedly connected to the top of the third resonant unit. The basic structure of the four-band pulse wave absorber consists of four resonant units. The bottom of the first resonant unit is fixedly connected to the top of the second resonant unit, the bottom of the second resonant unit is fixedly connected to the top of the third resonant unit, and the bottom of the third resonant unit is fixedly connected to the top of the fourth resonant unit. The first resonant unit, the second resonant unit, the third resonant unit and the fourth resonant unit are all composed of a front metal plate (2), an intermediate dielectric substrate (3), a rear metal plate (4) and a circuit module (1); the front side of the intermediate dielectric substrate (3) of each resonant unit is fixedly connected to the rear side of the front metal plate (2), and the rear side of the intermediate dielectric substrate (3) is fixedly connected to the front side of the rear metal plate (4). In the resonant unit: the rear metal plate (4) and the intermediate dielectric substrate (3) are both square, and the four sides of the rear metal plate (4) are flush with the four sides of the intermediate dielectric substrate (3), that is, the width B and height H of the resonant unit are equal; the front metal plate (2) is composed of two concave plates, the two concave plates are the same, the two concave plates are symmetrically fixed to the left and right sides of the center line of the intermediate dielectric substrate (3), the openings of the two concave plates face outward, the distance between the inner sides of the two concave plates is b0, and the depth b of the concave opening of the concave plate is half of the height h of the concave opening; the circuit module (1) is installed between the inner sides of the two concave plates, and the circuit module (1) is located at the middle position of the center line; The left and right sides of the front metal plate (2) are flush with the left and right sides of the intermediate dielectric substrate (3); the height H0 of the front metal plate (2) is 0.5 to 0.95 times the height H of the intermediate dielectric substrate (3); the upper and lower sides of the front metal plate (2) are equal to the upper and lower sides of their respective intermediate dielectric substrates (3). The circuit module (1) consists of a full-wave rectifier circuit, a capacitor C, and a resistor R. The four Schottky diodes of the full-wave rectifier circuit are, from left to right and from back to front, the first Schottky diode, the second Schottky diode, the third Schottky diode, and the fourth Schottky diode. The cathodes of the first and second Schottky diodes are connected, the anodes of the third and fourth Schottky diodes are connected, one end of the capacitor C is connected to the cathode of the first Schottky diode, and the other end of the capacitor C is connected to the anode of the third Schottky diode. One end of the resistor R is connected to the cathode of the second Schottky diode, and the other end of the resistor R is connected to the anode of the fourth Schottky diode. The anode of the first Schottky diode is connected to the inside of the left front metal plate (2), the anode of the second Schottky diode is connected to the inside of the right front metal plate (2), the cathode of the third Schottky diode is connected to the inside of the left front metal plate (2), and the cathode of the fourth Schottky diode is connected to the inside of the right front metal plate (2).

2. The multi-band pulse wave absorber based on capacitive nonlinear circuits according to claim 1, characterized in that... The front metal plate (2) and the rear metal plate (4) are made of the same material, namely copper, aluminum and silver.

3. The multi-band pulse wave absorber based on capacitive nonlinear circuits according to claim 1, characterized in that... The intermediate dielectric substrate (3) is an insulating material with a relative permittivity of 1.0 to 20.0; the thickness of the intermediate dielectric substrate (3) is t = 0.5 to 10 mm.

4. The multi-band pulse wave absorber based on capacitive nonlinear circuits according to claim 1, characterized in that... The dual-band pulse wave absorber: The width B of the intermediate dielectric substrate (3) and the rear metal plate (4) is 5 to 100 mm; The height h of the concave opening of the first resonant unit 21 =0.25~0.4B; The height h of the concave opening of the second resonant unit 22 =0.6~0.75B; Resistance R = 10kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF; The Schottky diode is model number HSMS-286x series.

5. The multi-band pulse wave absorber based on capacitive nonlinear circuits according to claim 1, characterized in that... The three-band pulse wave absorber: The width B of the intermediate dielectric substrate (3) and the rear metal plate (4) is 5 to 100 mm; The height h of the concave opening of the first resonant unit 31 =0.6~0.75B; The height h of the concave opening of the second resonant unit 32 =0.05~0.15B; The height h of the concave opening of the third resonant unit 33 =0.45~0.55B; Resistance R = 50kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF; The Schottky diode is model number HSMS-286x series.

6. The multi-band pulse wave absorber based on capacitive nonlinear circuits according to claim 1, characterized in that... The four-band pulse wave absorber: The width B of the intermediate dielectric substrate (3) and the rear metal plate (4) is 5 to 100 mm; The height of the concave opening of the first resonant unit is 0.45~0.55B; The height of the concave opening of the second resonant unit is 0.6–0.7B. The height of the concave opening of the third resonant unit is 0.8 to 0.9B. The height of the concave opening of the fourth resonant unit is 0.05~0.15B; Resistance R = 500kΩ ~ 100MΩ, capacitance C = 0.1nF ~ 100nF; The Schottky diode is model number HSMS-286x series.

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