A high-sensitivity electromagnetic sensing device and sensing method based on singular point effect

Abstract

This invention proposes a highly sensitive electromagnetic sensing device and method based on the singularity effect, belonging to the field of electromagnetic sensing technology. It includes: a first resonant unit, which is a lossy resonator; a second resonant unit, which is a resonator with added gain; and a coupling unit, which is a coupling capacitor placed between the first and second resonant units, forming a non-Hermitian coupled system. The system operates in a second-order singularity state under preset parameter conditions. When the measured medium is applied to the coupling unit, the equivalent coupling capacitance of the coupling unit changes, causing the singularity condition of the system to be disrupted, resulting in frequency splitting of the system's intrinsic frequencies. By detecting the frequency splitting characteristics, the change in the dielectric parameters of the measured medium is sensed. This invention significantly improves sensing sensitivity and resolution, and is suitable for applications such as biological detection, chemical analysis, and environmental monitoring in the microwave, millimeter-wave, and terahertz frequency bands.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic sensing technology, and more specifically, relates to a highly sensitive electromagnetic sensing device and sensing method based on the singularity effect. Background Technology

[0002] Electromagnetic sensing technology has been widely used in fields such as biological detection, chemical analysis, and environmental monitoring due to its advantages of being non-contact, having a fast response speed, and being easy to integrate. Most existing electromagnetic sensors are based on resonant structures, and their basic principle is to detect parameters by detecting changes in the resonant frequency, amplitude, or quality factor caused by the measured medium. However, the sensitivity of this type of sensor is usually limited by the quality factor and loss characteristics of the resonator, making it difficult to achieve both high sensitivity and stability in practical applications.

[0003] To improve sensing sensitivity, researchers have proposed various improvement schemes, such as using high-quality factor resonators, introducing metamaterial structures, or optimizing the local distribution of electromagnetic fields. However, while these methods improve sensitivity, they often place higher demands on the precision of structural fabrication, environmental stability, or measurement systems, and the improvement in sensitivity is limited, still failing to meet the need for high-resolution detection of weak dielectric disturbances.

[0004] In recent years, the singularity effect based on non-Hermitian physics has provided a new technical approach to overcome the limitations of traditional sensing sensitivity. In non-Hermitian coupled systems, when the system parameters are adjusted to a singularity, the system's eigenvalues ​​and eigenstates become degenerate, exhibiting a significantly enhanced response to small external perturbations. Existing research shows that near the singularity, the splitting of the system's eigenfrequency exhibits a nonlinear relationship with parameter perturbations, thus possessing the potential to achieve highly sensitive sensing.

[0005] However, existing singularity-based sensing schemes are mostly concentrated in the optical or acoustic fields. Their engineering implementation in the microwave and terahertz frequency bands still faces challenges such as complex structures, difficult control, and low coupling efficiency with actual sensing objects. In particular, there is a lack of simple, easily integrated, and practically applicable technical solutions for effectively converting minute changes in the dielectric parameters of the measured medium into measurable singularity perturbation responses while ensuring stable system operation.

[0006] Therefore, it is necessary to propose a device and sensing method with a reasonable structure, clear control method, and the ability to fully utilize the singularity effect to achieve highly sensitive electromagnetic sensing, so as to overcome the above-mentioned shortcomings in the existing technology. Summary of the Invention

[0007] To address the above-mentioned deficiencies or improvement needs of existing technologies, this invention provides a highly sensitive electromagnetic sensing device and sensing method based on the singularity effect, thereby solving the technical problem of insufficient response to weak dielectric parameter disturbances in existing electromagnetic sensing technologies.

[0008] To achieve the above objectives, according to one aspect of the present invention, a highly sensitive electromagnetic sensing device based on the singularity effect is provided, the sensing device comprising: a first resonant unit, a second resonant unit, and a coupling unit; The first resonant unit is a lossy resonator, and the first resonant unit includes a first resonant branch composed of a first inductor, a first capacitor and a positive resistor connected in series; The second resonant unit is a resonator that introduces gain. The second resonant unit includes a second resonant branch composed of a second inductor, a second capacitor, and a negative resistor connected in series. The coupling unit is a capacitive coupling structure. The coupling unit is used to couple the first resonant unit and the second resonant unit to form a non-Hermitian coupling system. The system operates in a second-order singularity state under preset parameter conditions. When the medium under test is loaded near or inside the coupling unit, the equivalent coupling capacitance of the coupling unit changes, which disrupts the singularity condition of the non-Hermitian coupling system and causes the intrinsic frequency of the system to split. By detecting the frequency splitting characteristics, the sensing of the medium under test can be achieved.

[0009] Preferably, the coupling unit adopts any one or a combination of interdigitated capacitor structure, parallel plate capacitor structure or gap capacitor structure.

[0010] Preferably, the first resonant unit adopts any one or a combination of a metal resonant structure, a dielectric resonant structure, or a metamaterial resonant structure; the second resonant unit adopts any one or a combination of a metal resonant structure, a dielectric resonant structure, or a metamaterial resonant structure.

[0011] Preferably, the gain of the second resonant unit is achieved by an active device, which includes an operational amplifier, a negative resistance module, or a transistor amplifier.

[0012] Preferably, the resonant frequency of the first resonant unit and the resonant frequency of the second resonant unit are the same or similar in the undisturbed state, and the loss and gain parameters of the first resonant unit and the second resonant unit satisfy the second-order singularity formation condition.

[0013] Preferably, the measured medium is applied to the coupling unit through a microfluidic channel, droplet loading, or direct filling.

[0014] Preferably, the splitting of the intrinsic frequency of the non-Hermitian coupling system is related to the square root of the change in the dielectric parameter of the measured medium.

[0015] In another aspect, the present invention provides a sensing method comprising the following steps: Step 1: Adjust the operating state of the non-Hermitian coupled system of the sensing device to a second-order singularity. Step 2: Load the medium under test near or inside the coupling unit to change the equivalent coupling capacitance of the coupling unit; Step 3: Detect the splitting characteristics of the intrinsic frequencies of the non-Hermitian coupled system in the output signal of the sensing device; Step 4: Obtain the intrinsic frequency splitting amount based on the splitting characteristics of the intrinsic frequency and determine the change in dielectric parameters of the measured medium.

[0016] Preferably, the intrinsic frequency split is obtained through frequency analysis, network analysis, or time-domain signal processing.

[0017] Preferably, the sensing method is applicable to microwave, millimeter wave, or terahertz frequency bands.

[0018] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. The high-sensitivity electromagnetic sensing device based on the singularity effect proposed in this invention couples a first resonant unit and a second resonant unit to form a non-Hermitian coupled system through a coupling unit, and enables the system to operate in a second-order singularity state under preset parameter conditions. The first resonant unit is configured as a lossy resonator, and the second resonant unit is configured as a resonator with introduced gain. By introducing gain and loss and constructing a second-order singularity operating state, this invention utilizes the ultra-sensitive response characteristics of the non-Hermitian coupled system to parameter perturbations near the singularity point to transform minute changes in dielectric parameters caused by the measured medium into significant intrinsic frequency splitting and frequency response changes, thereby achieving high-sensitivity detection of minute perturbations and improving sensing sensitivity and resolution.

[0019] 2. The highly sensitive electromagnetic sensing device based on the singularity effect proposed in this invention, wherein the coupling unit couples the first resonant unit and the second resonant unit to form a non-Hermitian coupling system, and the effective coupling between the measured medium and the singularity system is achieved through the capacitive coupling unit. The coupling unit includes an interdigital capacitor structure, a parallel plate capacitor structure or a gap capacitor structure. Its structural form is flexible and compatible with microfluidic channels or liquid loading methods, and is suitable for a variety of practical sensing scenarios.

[0020] 3. The highly sensitive electromagnetic sensing device based on the singularity effect proposed in this invention has a simple structure, is easy to integrate, and is suitable for microwave, millimeter wave and terahertz frequency bands. It has good application prospects in fields such as biological detection, chemical analysis and environmental monitoring. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the high-sensitivity electromagnetic sensing device based on the singularity effect of the present invention.

[0022] Figure 2 This is a circuit diagram of an embodiment of the negative resistance module in the high-sensitivity electromagnetic sensing device based on the singularity effect of the present invention.

[0023] Figure 3 This is a schematic diagram of the coupling unit being an interdigitated capacitor structure in the high-sensitivity electromagnetic sensing device based on the singularity effect of the present invention.

[0024] Figure 4 This is a schematic diagram of the voltage spectrum of the circuit node when the coupled double resonant circuit operates at a second-order singularity under perturbation-free conditions in an embodiment of the present invention, wherein the spectrum exhibits a single resonant peak characteristic.

[0025] Figure 5 This is a schematic diagram of the voltage spectrum of the circuit node when the coupling capacitor parameter is subjected to a perturbation in an embodiment of the present invention, in which the original single resonance peak splits and forms two resonance peaks.

[0026] Figure 6 The system frequency splitting value Δ in this embodiment of the invention f A schematic diagram showing the relationship between the square root of the perturbation intensity and the perturbation intensity shows that the two exhibit a linear trend.

[0027] Figure 7 This is a schematic diagram comparing the sensitivity of a sensing scheme based on the singularity effect and a traditional linear sensing scheme under the same perturbation conditions in an embodiment of the present invention, wherein the slope of the frequency response change characterizes the sensing sensitivity. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0029] like Figure 1As shown, this invention proposes a highly sensitive electromagnetic sensing device based on the singularity effect, comprising a first resonant unit, a second resonant unit, and a coupling unit disposed between the first and second resonant units. The first resonant unit is a lossy resonator, and the second resonant unit is a resonator with added gain. The two units form a non-Hermitian coupling system through the coupling unit and are adjusted to a second-order singularity state under preset parameter conditions.

[0030] Furthermore, the coupling unit is a capacitive coupling structure, and its equivalent coupling capacitance is sensitive to changes in the parameters of the measured medium applied nearby or inside it. When the measured medium causes a change in the equivalent coupling capacitance, the original singularity condition of the system is disrupted, causing the intrinsic frequencies of the non-Hermitian coupled system to split. By detecting the classification characteristics of these intrinsic frequencies, the sensing of changes in the dielectric parameters of the measured medium is achieved.

[0031] In a preferred embodiment of the present invention, the coupling unit may be any one or a combination of interdigitated capacitor structure, parallel plate capacitor structure or gap capacitor structure to enhance the electric field interaction between the measured medium and the coupling region and improve the sensing sensitivity.

[0032] As a preferred embodiment of the present invention, the first resonant unit and the second resonant unit may respectively adopt a metal resonant structure, a dielectric resonant structure or a metamaterial resonant structure to adapt to the needs of different operating frequency bands and application scenarios.

[0033] In a preferred embodiment of the present invention, the gain in the second resonant unit is achieved by an active device, which includes an operational amplifier, a negative resistance module, a transistor amplifier or its equivalent circuit, for compensating for system losses and satisfying the singularity formation conditions.

[0034] Embodiments of the present invention also propose a high-sensitivity sensing method based on the singularity effect, specifically including the following steps: Step 1: Construct the above-mentioned highly sensitive electromagnetic sensing device based on the singularity effect, and adjust the system parameters to make it work in the second-order singularity state; Step 2: Load the medium to be tested near or inside the coupling unit to change the equivalent coupling capacitance; Step 3: Detect the splitting characteristics of the intrinsic frequencies in the system output signal; Step 4: Determine the change in dielectric parameters of the measured medium based on the intrinsic frequency splitting amount.

[0035] To further explain, such as Figure 1 As shown, one embodiment of the present invention proposes a coupled double resonant circuit structure based on the singularity effect. This circuit includes a first resonant branch and a second resonant branch, which are coupled by a coupling capacitor. C0. Mutual coupling. The first resonant branch and the second resonant branch each include components composed of inductors. L With capacitor C The resonant structure is constructed, with a positive resistor introduced into one of the branches. R An equivalent negative resistance is introduced into the other branch. R This makes the entire system a non-Hermitian coupled system that simultaneously includes losses and gains. By appropriately selecting the inductor, capacitor, and resistor parameters, the two resonant branches can satisfy the operating conditions of second-order singularities under the condition of no external disturbances. At this time, the system's eigenfrequency becomes degenerate, providing a reference operating state for subsequent high-sensitivity sensing.

[0036] To further explain, such as Figure 2 As shown, in one embodiment of the present invention, the negative resistor - R This can be achieved using an active circuit. In this embodiment, the negative resistance module consists of an operational amplifier and multiple resistors. Through a specific feedback connection method, the module exhibits equivalent negative resistance characteristics within the operating frequency band. By adjusting the supply voltage of the operational amplifier and the parameters of the external resistors, the negative resistance module can provide the necessary gain compensation for the coupled double resonant circuit while ensuring stable circuit operation, thereby meeting the requirements for achieving the singularity condition.

[0037] To further explain, such as Figure 3 As shown, the coupling capacitor described in one embodiment of the present invention C The 0-axis capacitor employs an interdigitated capacitor structure. This structure consists of multiple interlaced electrode fingers, creating a strong concentrated electric field in the gap region between the electrodes. When the measured dielectric is applied to the electrode gap of the interdigitated capacitor or its vicinity, it alters the equivalent dielectric environment of that region, thereby inducing coupling capacitance. C The parameter variation is 0. This parameter variation is introduced as a perturbation input into the singular point coupled system to achieve high-sensitivity sensing.

[0038] To further explain, such as Figure 4 As shown, in one embodiment of the present invention, by adjusting the inductance, capacitance, and positive and negative resistance parameters in the coupled double resonant circuit, the system operates in a second-order singularity state under conditions free from external perturbations. In this state, the voltage response spectrum of the circuit nodes in the coupled double resonant circuit exhibits a single and sharp resonance peak. This single resonance peak corresponds to the intrinsic response degeneracy state of the system under singularity conditions and can serve as a reference for determining whether a perturbation has occurred during subsequent sensing processes.

[0039] To further explain, such as Figure 5As shown, in one embodiment of the present invention, when an external perturbation acts on the coupling capacitor structure, causing its parameters to change, the original second-order singularity condition is disrupted, and the coupled double resonant circuit changes from a degenerate state to a non-degenerate state. In this case, the original single resonant peak in the voltage response spectrum of the circuit node splits into two separate resonant peaks. This spectral splitting phenomenon reflects the system's high sensitivity to changes in coupling parameters.

[0040] To further explain, such as Figure 6 As shown, one embodiment of the present invention provides the system frequency splitting quantity Δ f The diagram illustrates the relationship between frequency splitting and the square root of the perturbation intensity. It can be seen that, within the shown operating range, the frequency splitting exhibits an approximately linear trend with the change of the square root of the perturbation intensity. By measuring the frequency difference corresponding to the resonant peak splitting, a qualitative or quantitative characterization of the perturbation intensity change can be achieved, thus providing a basis for sensing applications based on singularity effects.

[0041] To further explain, such as Figure 7 As shown, one embodiment of the present invention combines a coupled dual-resonant circuit sensing scheme based on the singularity effect with a traditional linear... RLC The resonant circuit sensing schemes were compared and analyzed under the same perturbation conditions. The comparison results show that, under the action of perturbation, the coupled dual resonant circuit based on the singularity effect exhibits a larger frequency response change, and the slope of its frequency change curve is significantly higher than that of the traditional linear sensing scheme, thus demonstrating higher sensing sensitivity.

[0042] This invention introduces gain and loss into a coupled dual-resonant circuit and constructs a second-order singularity operating state, transforming minute changes in coupling capacitor parameters into significant spectral splitting and frequency response changes, thus achieving highly sensitive detection of minute disturbances. This sensing scheme has a clear structure and well-defined implementation method, making it suitable for various sensing applications based on circuits or electromagnetic resonant structures.

[0043] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A highly sensitive electromagnetic sensing device based on the singularity effect, characterized in that, The sensing device includes: a first resonant unit, a second resonant unit, and a coupling unit; The first resonant unit is a lossy resonator, and the second resonant unit is a resonator that introduces gain. The coupling unit is a capacitive coupling structure. The coupling unit is disposed between the first resonant unit and the second resonant unit to couple the first resonant unit and the second resonant unit to form a non-Hermitian coupling system. The system operates in a second-order singularity state under preset parameter conditions. When the medium under test is loaded near or inside the coupling unit, the equivalent coupling capacitance of the coupling unit changes, which disrupts the singularity condition of the non-Hermitian coupling system and causes the system's intrinsic frequency to split. By detecting the frequency splitting characteristics, the change in the dielectric parameters of the medium under test can be sensed.

2. The highly sensitive electromagnetic sensing device based on the singularity effect according to claim 1, characterized in that, The coupling unit adopts any one or a combination of interdigitated capacitor structure, parallel plate capacitor structure, or gap capacitor structure.

3. The highly sensitive electromagnetic sensing device based on the singularity effect according to claim 1, characterized in that, The first resonant unit adopts any one or a combination of a metal resonant structure, a dielectric resonant structure, or a metamaterial resonant structure. The second resonant unit adopts any one or a combination of a metal resonant structure, a dielectric resonant structure, or a metamaterial resonant structure.

4. The highly sensitive electromagnetic sensing device based on the singularity effect according to claim 1, characterized in that, The gain of the second resonant unit is achieved through active devices, including operational amplifiers, negative resistance modules, or transistor amplifiers.

5. A highly sensitive electromagnetic sensing device based on the singularity effect according to claim 1, characterized in that, The resonant frequency of the first resonant unit and the resonant frequency of the second resonant unit are the same or similar under undisturbed conditions, and the loss and gain parameters of the first resonant unit and the second resonant unit satisfy the conditions for the formation of second-order singularities.

6. The highly sensitive electromagnetic sensing device based on the singularity effect according to claim 1, characterized in that, The medium under test is applied to the coupling unit through a microfluidic channel, droplet loading, or direct filling.

7. A highly sensitive electromagnetic sensing device based on the singularity effect according to claim 1, characterized in that, The splitting of the intrinsic frequency of the non-Hermitian coupling system is related to the square root of the change in the dielectric parameter of the measured medium.

8. A sensing method for a highly sensitive electromagnetic sensing device based on the singularity effect as described in any one of claims 1-7, characterized in that, The method includes the following steps: Step 1: Adjust the operating state of the non-Hermitian coupled system of the sensing device to a second-order singularity. Step 2: Load the medium under test near or inside the coupling unit to change the equivalent coupling capacitance of the coupling unit; Step 3: Detect the splitting characteristics of the intrinsic frequencies of the non-Hermitian coupled system in the output signal of the sensing device; Step 4: Obtain the intrinsic frequency splitting amount based on the splitting characteristics of the intrinsic frequency and determine the change in dielectric parameters of the measured medium.

9. The sensing method according to claim 8, characterized in that, The intrinsic frequency splitting quantity is obtained through frequency analysis, network analysis, or time-domain signal processing.

10. The sensing method according to claim 8, characterized in that, The sensing method is applicable to microwave, millimeter wave, or terahertz frequency bands.

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