An inversion control system and system based on the asymmetric transmission characteristics of radar waves

Abstract

The present invention discloses an inversion control system based on the asymmetric transmission characteristics of radar waves, which relates to the field of radar technology and includes: a radar wave transmitting module for transmitting a first radar wave; an inversion control module for receiving the first radar wave and filtering the first radar wave according to the asymmetric transmission characteristics of the radar wave to obtain a second radar wave; a radar wave receiving module for receiving and displaying the second radar wave; compared with most of the existing metamaterial structure designs, the radar wave material design of the present invention can achieve rapid inversion regulation at the nanosecond level in the transmission direction while realizing the asymmetric transmission function, and is expected to be applied to the in-band stealth of radar antennas.

Description

Technical Field

[0001] This application relates to the field of radar technology, and more particularly, to an inversion control system based on the asymmetric transmission characteristics of radar waves. Background Art

[0002] As one of the strong scattering sources of military platforms, the antenna contributes greatly to the total Radar Cross Section (RCS) of the system. However, different from general scatterers, when designing its stealth, it is necessary to ensure the emission and reception of its own electromagnetic waves. Currently, the main stealth technology means for antennas can be roughly divided into radome frequency selection technology, shape stealth technology, cancellation technology, etc. These technologies can only achieve stealth outside the working frequency band of the antenna (out-of-band stealth), and cannot solve the problem of detecting enemy antennas with the same frequency as our own, nor can they achieve stealth within the working frequency band (in-band stealth); or they solve the problem of in-band stealth design, but they need to be targeted at specific antenna structures, and the design process is complex and not universal; or due to the very strong volatility of the antenna mode term scattering and the structure mode term scattering in the resonance region, this technology has certain narrowband characteristics and it is difficult to maintain a stable in-band stealth effect. Therefore, it is necessary to develop in-band stealth technology for antennas while ensuring the normal radiation of our own antennas, that is, to achieve stealth from enemy detection.

[0003] Metamaterials are artificial composite structures or composite materials with extraordinary physical properties that natural materials do not possess. They can obtain the required special performance indicators through the design of microstructural units. In recent years, metamaterials have received more and more attention in the field of antennas and microwave engineering, and have great application potential and development space in improving the performance of antennas and reducing the RCS of antennas. Aiming at the characteristics of few measures, few ways, and difficult technology for current antenna in-band stealth technology, this patent proposes a design of a radar wave asymmetric transmission structure material with adjustable direction, which can achieve rapid inversion control at the nanosecond level of the transmission direction while realizing the asymmetric transmission function (the ratio of the electromagnetic wave energy propagating from one side of the material to the other side is significantly different from that in the opposite direction), and strive to achieve the in-band stealth effect of the antenna, ensuring the normal operation of our own antenna while not being detected by enemy antennas. Summary of the Invention

[0004] The object of the present invention is to propose a design of a radar wave asymmetric transmission structure material with adjustable direction, and construct an inversion system with nanosecond-level regulation of asymmetric transmission characteristics, providing certain technical support for solving the problem of in-band stealth of antennas.

[0005] To achieve the above object, the present invention provides an inversion control system based on the asymmetric transmission characteristics of radar waves, including:

[0006] A radar wave transmitting module for transmitting a first radar wave;

[0007] An inversion control module for receiving the first radar wave and filtering the first radar wave according to the asymmetric transmission characteristic of the radar wave to obtain a second radar wave;

[0008] A radar wave receiving module for receiving and displaying the second radar wave.

[0009] Preferably, the radar wave transmitting module includes a first signal source, a power amplifier, and a radar wave transmitting unit;

[0010] The first signal source is used to transmit a signal source with a center frequency of 10 GHz;

[0011] The first signal source is connected to the radar wave transmitting unit through a power amplifier.

[0012] Preferably, the inversion control module includes a square wave source, a first attenuator, and an asymmetric transmission filtering unit;

[0013] The square wave source is connected to the asymmetric transmission filtering unit through the first attenuator;

[0014] The asymmetric transmission filtering unit is used to convert the first electromagnetic wave into a second electromagnetic wave, wherein the asymmetric transmission filtering unit is a positive pulse load.

[0015] Preferably, the asymmetric transmission filtering unit is further used to convert the electromagnetic wave emitted by other electromagnetic wave emission systems into a third electromagnetic wave, wherein the asymmetric transmission filtering unit is a negative pulse load.

[0016] Preferably, the forward pulse voltage of the positive pulse load is 15 - 30 V;

[0017] The negative pulse voltage of the negative pulse load is -15 - -30 V.

[0018] Preferably, the asymmetric transmission filtering unit is composed of several groups of SRR structure units and varactor diodes, and each group of SRR structure units is respectively connected to two varactor diodes.

[0019] Preferably, the SRR structure unit is composed of a first copper metal square split ring resonator, a second copper metal square split ring resonator, and a dielectric layer arranged between the first copper metal square split ring resonator and the second copper metal square split ring resonator, wherein the dielectric layer is FR4, the dielectric constant is 4.2, and the dielectric loss is 0.025.

[0020] Preferably, the structures of the first copper metal square split ring resonator and the second copper metal square split ring resonator are the same;

[0021] The outer side length b of the first copper metal square split-ring resonator (SRR) and the second copper metal square split-ring resonator is 8 mm, the metal line width w is 2 mm, and the SRR slot size c is 2 mm.

[0022] Preferably, the included angle between the opening directions of the first copper metal square split-ring resonator and the second copper metal square split-ring resonator is 90°.

[0023] Preferably, the asymmetric transmission filter unit further includes a power line. When the width d of the power line is 0.1 and the distance p between the power line and the SRR structural unit is 1.8 mm, the asymmetric performance corresponding frequency band width of the SRR structural unit is the largest.

[0024] The present invention discloses the following technical effects:

[0025] Compared with most existing metamaterial structure designs, the radar wave material design of the present invention can achieve an asymmetric transmission function (the ratio of the electromagnetic wave energy propagating from one side of the material to the other side is significantly different from that in the opposite direction) while realizing a rapid inversion regulation at the nanosecond level of the transmission direction, and is expected to be applied to the in-band stealth of radar antennas. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 Schematic diagram of the SRR structural unit described in the present invention;

[0028] Figure 2 Schematic diagram of the SRR structural unit of the radar wave asymmetric transmission structure design scheme described in the present invention, (a) is the front view, (b) is the back view;

[0029] Figure 3 Schematic diagram of the process parameters affecting the electromagnetic wave transmittance described in the present invention, (a) is the front view, (b) is the back view;

[0030] Figure 4 Schematic diagram of the process parameters affecting the electromagnetic wave transmittance after exchanging the positive and negative poles of the circuit described in the present invention, (a) is the front view, (b) is the back view;

[0031] Figure 5 General design diagram of the circuit board described in the present invention;

[0032] Figure 6 Detail diagram of the circuit board described in the present invention;

[0033] Figure 7 This is the structural diagram of the radar wave asymmetric transmission characteristic inversion control system according to the present invention;

[0034] Figure 8 This is the forward and reverse transmittance curves of the SRR structure according to the present invention. Detailed implementation manners

[0035] In order to make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Usually, the components of the embodiments of the present application described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application to be protected, but only represents the selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0036] As Figure 1-8 shown, the present invention provides an inversion control system based on the radar wave asymmetric transmission characteristic, including:

[0037] A radar wave transmitting module for transmitting the first radar wave;

[0038] An inversion control module, configured to receive the first radar wave and, after filtering the first radar wave according to the radar wave asymmetric transmission characteristic, obtain the second radar wave;

[0039] A radar wave receiving module for receiving and displaying the second radar wave.

[0040] Further, the radar wave transmitting module includes a first signal source, a power amplifier, and a radar wave transmitting unit;

[0041] The first signal source is used to transmit a signal source with a center frequency of 10 GHz;

[0042] The first signal source is connected to the radar wave transmitting unit through the power amplifier.

[0043] Further, the inversion control module includes a square wave source, a first attenuator, and an asymmetric transmission filtering unit;

[0044] The square wave source is connected to the asymmetric transmission filtering unit through the first attenuator;

[0045] The asymmetric transmission filtering unit is used to convert the first electromagnetic wave into the second electromagnetic wave, wherein the asymmetric transmission filtering unit is positive pulse loading.

[0046] Further, the asymmetric transmission filtering unit is also configured to convert electromagnetic waves emitted by other electromagnetic wave transmitting systems into third electromagnetic waves, wherein the asymmetric transmission filtering unit is loaded with negative pulses.

[0047] Further, the forward pulse voltage for positive pulse loading is 15 - 30V;

[0048] The negative pulse voltage for negative pulse loading is -15 - -30V.

[0049] Further, the asymmetric transmission filtering unit is composed of several groups of SRR structure units and varactor diodes, wherein each group of SRR structure units is respectively connected to two varactor diodes.

[0050] Further, the SRR structure unit is composed of a first copper metal square split-ring resonator, a second copper metal square split-ring resonator, and a dielectric layer disposed between the first copper metal square split-ring resonator and the second copper metal square split-ring resonator, wherein the dielectric layer is FR4, the dielectric constant is 4.2, and the dielectric loss is 0.025.

[0051] Further, the structures of the first copper metal square split-ring resonator and the second copper metal square split-ring resonator are the same;

[0052] The outer side length b of the structures of the first copper metal square split-ring resonator and the second copper metal square split-ring resonator is 8mm, the metal line width w is 2mm, and the SRR gap size c is 2mm.

[0053] Further, the included angle between the opening directions of the first copper metal square split-ring resonator and the second copper metal square split-ring resonator is 90°.

[0054] Further, the model of the varactor diode is SS320F, the conduction voltage is 0.7V, and the intrinsic resistance is 143Ω;

[0055] The asymmetric transmission filtering unit further includes a power line. When the width d of the power line is 0.1 and the distance p between the power line and the SRR structure unit is 1.8mm, the asymmetric performance corresponding frequency band width of the SRR structure unit is the largest.

[0056] Further, the present invention provides an asymmetric transmission method, including, when positive pulse loading, controlling the voltage applied to the asymmetric transmission material to be a positive voltage; when negative pulse loading, controlling the voltage applied to the asymmetric transmission material to be a negative voltage, realizing the change of the orientation of the notch of the SRR structure resonator ring, thereby changing the polarization mode of the asymmetric transmission material, and realizing the alternating flip of the controllable transmission direction of the material.

[0057] When our antenna emits electromagnetic waves, adjust the direction of the pulsed voltage to maximize the forward electromagnetic wave transmittance and minimize the reverse transmittance of the asymmetric transmission material. At this time, the electromagnetic waves emitted by our antenna can pass through the material to detect the enemy target, while the electromagnetic waves emitted by the enemy antenna cannot pass through the material and are scattered to a safe direction; when our antenna receives electromagnetic waves, adjust the pulsed voltage to the opposite direction to maximize the reverse electromagnetic wave transmittance and minimize the forward transmittance of the asymmetric transmission material. The echo detected by our antenna can pass through the material and be received by the antenna, while the enemy's co-frequency electromagnetic waves can also enter but are absorbed by the internal wave-absorbing material, etc., and because the forward transmittance is minimized, the electromagnetic waves cannot return to the enemy antenna.

[0058] Example 1: The radar wave asymmetric transmission structure material is based on Figure 1 the unit model shown. This model consists of two layers of copper metal split ring resonator (SRR) structures with a layer of dielectric in between. The included angle between the opening directions of the bottom SRR structure and the surface SRR structure is 90°. The outer side length of the structure b = 8 mm, the metal wire width w = 2 mm, the SRR gap size c = 2 mm, the intermediate dielectric is FR4, the dielectric constant is 4.2, and the dielectric loss is 0.025.

[0059] Based on the above optimized unit model, using the controllable phase change characteristics of varactor diodes, two diodes are loaded on the SRR structure unit, and two sets of power supplies are used to control the front and back patterns respectively. The front and back patterns of the model are as Figure 2 shown.

[0060] On Figure 2 the basis of the two sets of circuits designed, use CST software to optimize the process parameters affecting the electromagnetic wave transmittance, such as Figure 3 shown. The obtained results are as follows: the power supply line width d = 0.1, the distance p between the power supply line and the SRR structure is 1.8 mm, making the asymmetric performance of the material have the maximum corresponding frequency band width.

[0061] And by swapping the positive and negative poles of the power supply, changing the positive and negative poles of the power supply will cause the conducting diode in one unit to turn off and the other diode to conduct, becoming a model as Figure 4 shown. The transmission characteristics of electromagnetic waves for this structure are Figure 3 opposite, so the conversion characteristic of electromagnetic wave transmission can be achieved.

[0062] Based on the simulation results of the above flip control technology modeling, designed as Figure 5The shown metamaterial circuit sample loaded with diodes has 900 SRR structures loaded with diodes on both the front and back sides, a total of 1800, and a total of 3600 diodes. The diodes are arranged back to back, and each diode is connected to the positive and negative poles of the power supply. The 1800 diodes on each side are connected in parallel with each other and connected to the two poles of the power supply. The diode model is SS320F, the conduction voltage is 0.7V, and the intrinsic resistance is 143Ω. The design details are as Figure 6 shown.

[0063] The flipping of the unidirectional transmission characteristic of radar waves is achieved by applying square wave pulses of nanosecond-level positive / negative polarities. The detection and implementation methods are as Figure 7 shown. An electromagnetic wave with vertical polarization is emitted from the transmitting end by a signal source with a center frequency of 10 GHz, amplified by a power amplifier, and after passing through an asymmetric transmission material sample board ( Figure 5 designed circuit board), the signal is received at the receiving end of the antenna, and the signal is attenuated by an attenuator, and the S parameter is displayed on an oscilloscope.

[0064] The signal source in this system is a square wave source, which is driven by a pulse modulation signal to achieve the controllable asymmetric transmission characteristic of radar waves. The positive and negative polarities of the pulse modulation signal determine the forward and reverse directions of the asymmetric transmission material. When a positive pulse is loaded, the voltage applied to the asymmetric transmission material is controlled to be a positive voltage; when a negative pulse is loaded, the voltage applied to the asymmetric transmission material is controlled to be a negative voltage, realizing the change in the orientation of the notch of the SRR structure resonance ring, and further changing the polarization mode of the asymmetric transmission material, achieving the alternating flipping of the controllable transmission direction of the material.

[0065] Regulate the positive and negative pulse voltages of the square wave source according to the working state of our own antenna. When our antenna emits electromagnetic waves, adjust the direction of the pulse voltage to make the forward electromagnetic wave transmittance of the asymmetric transmission material the largest and the reverse transmittance the smallest. At this time, the electromagnetic waves emitted by our antenna can pass through the material to detect enemy targets, while the electromagnetic waves emitted by the enemy antenna cannot pass through the material and are scattered to a safe direction; when our antenna receives electromagnetic waves, adjust the pulse voltage to the opposite direction to make the reverse electromagnetic wave transmittance of the asymmetric transmission material the largest and the forward transmittance the smallest. The detection echo of our antenna can pass through the material and be received by the antenna, while the co-frequency electromagnetic waves of the enemy can also enter, but are absorbed by the internal wave-absorbing materials, etc., and because the forward transmittance is the smallest, the electromagnetic waves cannot return to the enemy antenna. Therefore, the in-band stealth effect of the antenna is effectively achieved.

[0066] Since the speed of the flip time depends on the time response performance of the key diodes in the circuit, a square wave source with a rise time of 1 ns is used to test the time response characteristics of the diodes. The peak voltage UP of the square wave pulse and the balanced voltage UCV of the clamped waveform are obtained respectively, and the median voltage Ut = (UP + UCV) / 2 is calculated. The pulse width of the attenuated pulse waveform at Ut and the response time △t of the diode are calculated. It can be calculated that the response time △t of the diode is 5 ns. Therefore, after the square wave source controls the asymmetric transmission characteristics, nanosecond-level inversion can be achieved.

[0067] Embodiment 2: Figure 3 The comparison of the forward and backward transmittances of the designed SRR structure model is as Figure 8 shown. It can be seen that the maximum forward transmittance is 0.62 at 11.6 GHz, and the corresponding backward transmittance is 0.06, achieving an obvious electromagnetic wave asymmetric transmission effect on the front and back. This structure is mirror-asymmetric in the x and y directions. The electric field of x (or y) polarization will excite the magnetic dipole mode of one of the slotted rings, and this mode will in turn excite the magnetic dipole mode of the other slotted ring, and an electric dipole of y (or x) polarization will be generated at the slot, achieving polarization conversion and changing the energy of different polarized electromagnetic waves passing through.

[0068] It should be noted that: similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0069] Finally, it should be noted that: the above-described embodiments are only specific embodiments of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. All should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An inversion control system based on the asymmetric transmission characteristics of radar waves, characterized in that, Comprising: A radar wave transmitting module for transmitting a first radar wave; An inversion control module for receiving the first radar wave and filtering the first radar wave according to the asymmetric transmission characteristic of the radar wave to obtain a second radar wave; A radar wave receiving module for receiving and displaying the second radar wave; The radar wave transmitting module includes a first signal source, a power amplifier, and a radar wave transmitting unit; The first signal source is connected to the radar wave transmitting unit through the power amplifier; The inversion control module includes a square wave source, a first attenuator, and an asymmetric transmission filtering unit; The square wave source is connected to the asymmetric transmission filtering unit through the first attenuator; The asymmetric transmission filtering unit is used to convert the first radar wave into the second radar wave. Among them, the asymmetric transmission filtering unit is positive pulse loading; the asymmetric transmission filtering unit is composed of several groups of SRR structure units and varactor diodes, and each group of SRR structure units is respectively connected to two of the varactor diodes; The SRR structure unit is composed of a first copper metal square split ring resonator, a second copper metal square split ring resonator, and a dielectric layer disposed between the first copper metal square split ring resonator and the second copper metal square split ring resonator. The included angle between the opening directions of the first copper metal square split ring resonator and the second copper metal square split ring resonator is 90°; The asymmetric transmission filtering unit is further used to convert the electromagnetic waves emitted by other electromagnetic wave emission systems into third electromagnetic waves, where the asymmetric transmission filtering unit is negative pulse loading.

2. The inversion control system based on the asymmetric transmission characteristic of radar waves according to claim 1, wherein: The forward pulse voltage of the positive pulse loading is 15 - 30V; The negative pulse voltage of the negative pulse loading is -15 - -30V.

3. The inversion control system based on the asymmetric transmission characteristic of radar waves according to claim 1, wherein: The first signal source is used to emit a signal source with a center frequency of 10 GHz.

4. The inversion control system based on the asymmetric transmission characteristic of radar waves according to claim 3, wherein: The dielectric layer is FR4, with a dielectric constant of 4.2 and a dielectric loss of 0.

025.

5. The inversion control system based on the asymmetric transmission characteristic of radar waves according to claim 4, wherein: The structures of the first copper metal square split ring resonator and the second copper metal square split ring resonator are the same; The outer side length b of the structures of the first copper metal square split ring resonator and the second copper metal square split ring resonator is 8 mm, the metal line width w is 2 mm, and the SRR gap size c is 2 mm.

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