Electromagnetic sensor stealth structure with enhanced sensitivity

Abstract

The invention relates to the technical fields of electromagnetic sensing, stealth technology and electromagnetic wave regulation and control. An existing sensor structure still has the limitations that invisibility, signal enhancement and stable electric connection cannot be achieved at the same time, and the sensitivity and the invisibility performance restrict each other. The invention discloses an electromagnetic sensor stealth structure capable of enhancing sensitivity, which is characterized in that a plurality of hidden areas and a high-refractive-index core detection area are arranged in an anisotropic medium shell layer, and sub-wavelength communication holes are formed between the hidden areas and the high-refractive-index core detection area; electromagnetic waves can be guided to bypass the sensor main body to realize invisibility, meanwhile, the electromagnetic waves are converged to a high-refractive-index core detection area to realize signal enhancement, and the effect of stable electric connection between the sensor main body and the probe is maintained; the method is applied to the fields of ultra-weak signal detection, stealth monitoring, biosensing, radar detection and the like.

Description

Technical Field

[0001] This invention relates to the fields of electromagnetic sensing, stealth technology, and electromagnetic wave manipulation technology, and more specifically, to a stealth structure for an electromagnetic sensor that enhances sensitivity. Background Technology

[0002] The detection of extremely weak electromagnetic signals is crucial in many fields, including brain signal detection, single-molecule imaging, quantum sensing, astrophysical detection, and biomedical detection. However, traditional sensors face two major challenges in weak signal detection: first, the intensity of weak electromagnetic signals is extremely low, making it difficult for conventional sensors to capture them effectively; second, the physical presence of the sensor inevitably disturbs the surrounding electromagnetic field distribution, leading to signal distortion, and the sensor itself is easily detectable, failing to meet special needs such as stealth monitoring.

[0003] In existing technologies, sensitivity enhancement and sensor stealth are usually achieved through independent structural designs, lacking a unified solution that can simultaneously achieve both goals. For example, complementary open-loop resonators and folded structures can improve sensor sensitivity, but cannot solve the problems of sensor disturbance to electromagnetic fields and self-stealth. While stealth technologies such as plasma shells and metasurface stealth cloaks can reduce sensor scattering, they cannot enhance signal detection sensitivity and are difficult to simultaneously eliminate direct scattering from the sensor body (large electrical size) and indirect scattering from the probe (subwavelength scale), and may also disrupt the electrical connection between the sensor body and the probe.

[0004] Currently, there is still a lack of a structure that can simultaneously achieve sensor stealth, reduce electromagnetic field disturbances, and significantly improve detection sensitivity while ensuring a stable electrical connection between the sensor body and the probe. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, this invention proposes a stealth structure for an electromagnetic sensor that enhances sensitivity. Through a multifunctional core-shell structure design, the structure achieves sensor stealth (i.e., scatter suppression) while enhancing the electromagnetic signal strength in the detection area and maintaining the electrical connection between the sensor body and the probe. This stealth structure, which combines stealth functionality with enhanced sensitivity, is suitable for scenarios such as ultra-weak signal detection, stealth monitoring, biosensing, radar detection, intelligent control, and information security systems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An electromagnetic sensor stealth structure with enhanced sensitivity includes an anisotropic dielectric shell, within which several hidden regions and a high refractive index core detection region are arranged. A subwavelength connecting hole is arranged between the hidden regions and the high refractive index core detection region. The hidden regions are distributed outside the high refractive index core detection region. The sensor body is placed within the hidden regions, and the sensor probe passes through the connecting hole at the connection between the high refractive index core detection region and the hidden regions.

[0007] Furthermore, the diameter of the connecting hole is no greater than 0.05λ0, where λ0 represents the center wavelength of the electromagnetic wave being detected.

[0008] Furthermore, the conductive metal tip of the sensor probe extends into the high-refractive-index core detection area, and the coaxial cable portion of the sensor probe is located in the hidden area and connected to the sensor body, thereby achieving a stable electrical connection between the sensor body and the sensor probe.

[0009] Furthermore, the diameter of the conductive metal tip of the sensor probe w t Smaller than the diameter of the coaxial cable portion of the sensor probe w p The length of the conductive metal tip extending into the high-refractive-index core detection region is l t ,and l t =0.05λ0, where λ0 represents the center wavelength of the detected electromagnetic wave.

[0010] Furthermore, the refractive index of the high refractive index core detection region is L2 / L1, where L2 is the outer boundary perimeter of the anisotropic medium shell and L1 is the boundary perimeter of the high refractive index core detection region.

[0011] Furthermore, the dielectric constant and permeability of the anisotropic dielectric shell approach infinity in the principal axis direction and are equal to zero in the other two perpendicular directions.

[0012] In summary, the present invention has the following beneficial effects: In this invention, the anisotropic dielectric shell guides electromagnetic waves around the hidden region where the sensor body is located, while suppressing indirect scattering of the probe through a scattering cancellation mechanism. Compared with a standalone sensor system, this invention can reduce the scattering cross-section by more than 20dB, achieving efficient stealth without disturbing the external electromagnetic field distribution. Sensitivity is significantly enhanced: through the compression transformation of transform optics, the anisotropic dielectric shell converges weak external electromagnetic signals into the high-refractive-index core of the detection region, significantly increasing the electromagnetic signal power absorbed by the sensor probe and effectively improving the weak signal detection capability. The shape, number, and size of the hidden region can be flexibly adjusted through coordinate transformation, adapting to electrically large sensor bodies of any shape and size. The subwavelength connecting hole ensures a stable electrical connection between the sensor body and the sensor probe without affecting the original working mechanism of the sensor. It simultaneously achieves stealth and enhanced sensitivity functions over a wide frequency range, with broad applicability, and can be extended to other physical field sensors such as thermal and acoustic field sensors, or multi-physical field sensors. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the stealth structure of the electromagnetic sensor with enhanced sensitivity according to the present invention.

[0014] Figure 2 yes Figure 1 A magnified view of part A in the middle.

[0015] Figure 3 Simulation verification diagram of the stealth effect of the present invention.

[0016] Figure 4 Simulation verification diagram of the electromagnetic detection enhancement effect of the present invention.

[0017] In the figure, 1 is the high refractive index core detection area, 2 is the hidden area, 3 is the anisotropic medium shell, 4 is the coaxial cable part of the sensor probe, 5 is the conductive metal tip of the sensor probe, and 6 is the sensor body. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and examples.

[0019] It should be noted that, for ease of description, the descriptions of direction in the following text are consistent with the directions in the accompanying drawings, but they do not limit the structure of the present invention.

[0020] like Figures 1-4As shown, this invention discloses a stealth structure for an electromagnetic sensor with enhanced sensitivity. The external region of the stealth structure is an air environment, including an anisotropic dielectric shell 3. Several hidden regions 2 and a high refractive index core detection region 1 are arranged within the anisotropic dielectric shell 3. A subwavelength connecting hole is provided between the hidden regions 2 and the high refractive index core detection region 1. The diameter of the connecting hole is no greater than 0.05λ0, where λ0 represents the center wavelength of the detected electromagnetic wave. The anisotropic dielectric shell 3 can guide external incident electromagnetic waves to bypass the hidden regions 2, avoiding interaction with the sensor body, and simultaneously tunneling and converging the electromagnetic waves without distortion into the high refractive index core detection region 1, thereby enhancing the electromagnetic signal. Hidden regions 2 are located outside the high-refractive-index core detection region 1, with the sensor body placed within them. The sensor body within hidden regions 2 can be adjusted according to actual usage requirements; a sensor body can be placed in every hidden region 2, or in one or several hidden regions. Whether or not a sensor body is placed in each hidden region 2 does not affect the detection of other regions. The shape and size of hidden regions 2 can be arbitrarily set, ensuring that the sensor body is completely within them. The sensor probe passes through the connection point between the high-refractive-index core detection region 1 and hidden regions 2 via a connecting hole. The conductive metal tip 5 of the sensor probe extends into the high-refractive-index core detection region 1, and the coaxial cable portion 4 of the sensor probe is located within hidden regions 2 and connected to the sensor body, achieving a stable electrical connection between the sensor body and the sensor probe.

[0021] The conductive metal tip of the sensor probe has a diameter of 5 mm. t The diameter w of the coaxial cable portion 4 smaller than that of the sensor probe p The length of the conductive metal tip 5 extending into the high-refractive-index core detection region 1 is... l t ,and l t =0.05λ0.

[0022] The refractive index of the high refractive index core detection region 1 is L2 / L1, where L2 is the outer perimeter of the anisotropic medium shell 3 and L1 is the boundary perimeter of the high refractive index core detection region 1. The dielectric constant and permeability of the anisotropic medium shell 3 approach infinity in the principal axis direction and are equal to zero in the other two perpendicular directions.

[0023] Example: In this example, the operating wavelength of the electromagnetic wave is designed to be λ0 = 1 m. Figure 1 The size parameters of the electromagnetic wave energy enhancement structure described in the text are selected as follows: R 1 = 0.3λ0, R 2 = 2 R 1, R 3 = 3.16R 1; In this embodiment, the number of sensor bodies is 1, and 4 hidden regions 2 are evenly distributed in a circular array around the high refractive index core detection region 1. The number and position of the hidden regions 2 can be adjusted according to actual usage requirements. The scattering cross section reduction effect can be achieved by symmetrical or asymmetrical distribution.

[0024] Figure 3 This is a diagram of the scattering cross-section reduction factor. Figure 3 The results show that when the diameter of the coaxial cable portion 4 of the sensor probe varies from λ0 / 40 to λ0 / 20, a good scattering cross-section reduction effect (>20 dB) can be obtained. Figure 4 It is a map of the energy density enhancement factor in the detection area. Figure 4 The results show that when the coaxial cable diameter varies from λ0 / 40 to λ0 / 10, a good enhancement effect on the energy density of the detection area can be obtained (>7).

[0025] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A stealth structure for an enhanced sensitivity electromagnetic sensor, characterized in that, The device includes an anisotropic medium shell (3), within which are arranged several hidden regions (2) and a high refractive index core detection region (1). A subwavelength connecting hole is provided between the hidden regions (2) and the high refractive index core detection region (1). The hidden regions (2) are located outside the high refractive index core detection region (1), and the sensor body is placed inside the hidden regions (2). The sensor probe passes through the connecting hole at the connection between the high refractive index core detection region (1) and the hidden regions (2).

2. The electromagnetic sensor stealth structure with enhanced sensitivity according to claim 1, characterized in that, The diameter of the connecting hole is no greater than 0.05λ0, where λ0 represents the center wavelength of the electromagnetic wave being detected.

3. The electromagnetic sensor stealth structure with enhanced sensitivity according to claim 1, characterized in that, The conductive metal tip (5) of the sensor probe extends into the high refractive index core detection area (1), and the coaxial cable part (4) of the sensor probe is located in the hidden area (2) and connected to the sensor body, so as to realize a stable electrical connection between the sensor body and the sensor probe.

4. The electromagnetic sensor stealth structure with enhanced sensitivity according to claim 3, characterized in that, The diameter w of the conductive metal tip (5) of the sensor probe t The diameter w of the coaxial cable portion (4) smaller than that of the sensor probe p The length of the conductive metal tip (5) extending into the high refractive index core detection region (1) is... l t ,and l t =0.05λ0, where λ0 represents the center wavelength of the detected electromagnetic wave.

5. The electromagnetic sensor stealth structure with enhanced sensitivity according to claim 1, characterized in that, The refractive index of the high refractive index core detection region (1) is L2 / L1, where L2 is the outer boundary perimeter of the anisotropic medium shell (3) and L1 is the boundary perimeter of the high refractive index core detection region (1).

6. The electromagnetic sensor stealth structure with enhanced sensitivity according to claim 1, characterized in that, The dielectric constant and permeability of the anisotropic dielectric shell (3) approach infinity in the principal axis direction and are equal to zero in the other two perpendicular directions.

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