A dielectric constant measuring device and method

Abstract

The embodiment of the application provides a kind of dielectric constant measuring device and method, it is applicable to terahertz technical field.The method comprises: by the dielectric sensor structure based on the artificial plasmonic waveguide after structure improvement, the dielectric constant of dielectric material is measured in terahertz frequency band, specifically, by changing the metal layer geometric parameter of waveguide specific part, the function of waveguide is changed from transmission to sensing, then according to the sample of different dielectric constant, the resonance peak center frequency of the dielectric sensor is shifted, and the dielectric constant of the sample to be measured is calculated by the shift amount of resonance peak center frequency.The device for executing the method includes artificial plasmonic waveguide based on it, with the advantages of simple structure, easy processing, good sensitivity and the like.The dielectric constant measurement method can simply and quickly determine the dielectric constant of trace small sample.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of terahertz, and particularly relates to a dielectric constant measuring device and method. BACKGROUND

[0002] Artificial surface plasmon is a kind of electromagnetic wave which is strictly bound to the surface of a device and propagates along the surface of metal and dielectric and exponentially attenuates in the direction perpendicular to the wave. In order to popularize the concept of surface plasmon to the low frequency band (such as the microwave and terahertz band) and realize the high-constraint propagation of surface electromagnetic wave in the microwave and terahertz band, an artificial surface plasmon can be obtained by digging holes or grooves on the surface of metal, and the advantage is that the propagation of electromagnetic wave can be controlled by simply changing the geometric parameters of the sub-wavelength metal structure.

[0003] Terahertz wave generally refers to electromagnetic radiation with a frequency of 0.1 THz to 10 THz, which has been limited for a long time due to the lack of effective terahertz generation sources and detection means, and this band is also called the terahertz gap. At present, the application of artificial plasmon in the terahertz dielectric sensing has not been fully explored and developed.

[0004] In the terahertz band, the existing structure of the artificial surface plasmon dielectric sensor is generally non-planar, which leads to the low compactness of the system obtained by integrating the artificial surface plasmon waveguide and the vector network analyzer. SUMMARY

[0005] The dielectric constant measuring device and method provided by the embodiments of the application change the size of the center unit of the waveguide dielectric sensor, change the function of the waveguide from transmission to sensing, and calculate the dielectric constant of the sample to be measured according to the resonance peak center frequency offset of the sample to be measured, thereby solving the problem of simple and fast measurement of the dielectric constant of a small sample.

[0006] In a first aspect, a structure of a dielectric constant measuring device is provided, which comprises: a waveguide dielectric sensor, the waveguide dielectric sensor comprising a first port and a second port, a first transition region located on the side of the first port, a second transition region located on the side of the second port, a center unit region, a first transmission region located between the first port and the first transition region, and a second transmission region located between the second port and the second transition region; and a vector network analyzer, the vector network analyzer comprising a third port and a fourth port, the first port of the waveguide dielectric sensor being connected to the third port of the vector network analyzer, and the second port of the waveguide dielectric sensor being connected to the fourth port of the vector network analyzer.

[0007] In some implementations of the first aspect, the first transition region and the second transition region are symmetric with respect to a center position of the waveguide dielectric sensor, the center unit region is located at a center region of the waveguide dielectric sensor, the first transition region and the second transition region and the center unit region each include a plurality of metal grids, a length of the metal grid located at the center position is greater than a length of other metal grids; the length of the metal grid located at the first transition region uniformly decreases in a direction pointing from the center position to the first port; and the length of the metal grid located at the second transition region uniformly decreases in a direction pointing from the center position to the second port.

[0008] In some implementations of the first aspect, a length of the metal grid located at the center position is set to any length greater than 150 microns and less than 300 microns.

[0009] In some implementations of the first aspect, a length of the metal grid located at the first transmission region and the second transmission region, and a length of the metal grid located at the center unit region except the center position is set to any length greater than 0 microns and less than 100 microns.

[0010] In some implementations of the first aspect, the length of the metal grid located at the first transition region uniformly decreases in the direction pointing from the center position to the first port until the length of the metal grid reaches a first threshold; and the length of the metal grid located at the second transition region uniformly decreases in the direction pointing from the center position to the second port until the length of the metal grid reaches the first threshold.

[0011] In some implementations of the first aspect, the waveguide dielectric sensor includes a substrate, an upper surface of the substrate has a periodic distribution of a metal grid array along a length direction of the waveguide dielectric sensor, the metal grid array includes a plurality of the metal grids, and the metal grids have a one-dimensional groove structure therebetween.

[0012] In some implementations of the first aspect, a material of the substrate of the waveguide dielectric sensor is silicon and / or sapphire.

[0013] In some implementations of the first aspect, a material of the metal grid is gold and / or copper.

[0014] In some implementations of the first aspect, the first port of the waveguide dielectric sensor is connected to the third port of the vector network analyzer, and the second port of the waveguide dielectric sensor is connected to the fourth port of the vector network analyzer.

[0015] In a second aspect, a dielectric constant measurement method is provided, which is applied to a dielectric constant measurement device including a waveguide dielectric sensor and a vector network analyzer. The method includes: placing a sample to be measured in a central unit region of the waveguide dielectric sensor; receiving, through a first port of the waveguide dielectric sensor, a transverse electromagnetic wave signal fed in by a third port of the vector network analyzer; outputting, by a second port of the waveguide dielectric sensor, a transverse magnetic wave signal to a fourth port of the vector network analyzer; obtaining a resonance curve corresponding to the sample to be measured, wherein a frequency corresponding to a minimum value of transmission efficiency of the resonance curve is a center frequency of a resonance peak, and the center frequency of the resonance peak corresponds to a dielectric constant of the sample to be measured in a one-to-one manner; and obtaining the dielectric constant of the sample to be measured according to the resonance peak of the sample to be measured and a resonance peak of a preset standard sample.

[0016] In some implementations of the first aspect, the dielectric constant and the center frequency of the resonance peak of the plurality of standard samples are measured to obtain a plurality of center frequencies of the resonance peaks when the dielectric constants of the plurality of standard samples change, the center frequencies of the resonance peaks correspond to the dielectric constants of the standard samples in a one-to-one manner, a frequency offset rule is obtained from the corresponding relationship, and the dielectric constant of the sample to be measured is calculated according to the frequency offset rule and a numerical value of the center frequency of the resonance peak of the sample to be measured. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a top view of a waveguide dielectric sensor of a dielectric constant measurement device according to an embodiment of the present application.

[0018] Figure 2 FIG. 1 is a top view of a waveguide dielectric sensor of a dielectric constant measurement device according to an embodiment of the present application.

[0019] Figure 3 FIG. 1 is a top view of a waveguide dielectric sensor of a dielectric constant measurement device according to an embodiment of the present application.

[0020] Figure 4 FIG. 1 is a top view of a waveguide dielectric sensor of a dielectric constant measurement device according to an embodiment of the present application.

[0021] Figure 5is a schematic diagram of a rate of change of a frequency shift of a sample with respect to a refractive index based on a dielectric constant measurement device and method provided by an embodiment of the present application.

[0022] Figure 6 is a working process schematic diagram of a dielectric constant measurement system based on a dielectric constant measurement device and method provided by an embodiment of the present application.

[0023] Figure 7 is a transmission spectrum diagram when measuring different dielectric constant samples based on a dielectric constant measurement device and method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0024] In the following description, for the purposes of explanation and not limitation, specific details are set forth, such as particular system configurations, techniques, etc., in order to provide a thorough understanding of the embodiments of the application. However, it will be apparent to those skilled in the art that the application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the application with unnecessary detail.

[0025] It should be understood that the term “includes” when used in the specification and the appended claims herein, indicates the presence of the described features, integers, steps, operations, elements, and / or components but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0026] It should also be understood that the term “and / or” when used in the specification and the appended claims herein, means any one or more of the associated listed items or a combination thereof.

[0027] As used in the description of the application and the appended claims herein, the term “if’ can be interpreted as meaning “when” or “upon” or “in response to a determination” or “in response to a detection” depending on the context. Similarly, the phrase “if determined” or “if detected [the described condition or event]” can be interpreted as meaning “upon a determination” or “in response to a determination” or “upon a detection of [the described condition or event]” or “in response to a detection of [the described condition or event]” depending on the context.

[0028] In addition, in the description of the application and the appended claims herein, the terms “first”, “second”, “third”, etc. are used only to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

[0029] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0030] The present invention will be further illustrated below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. After reading this invention, any modifications of the present invention by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

[0031] As introduced in the background section, besides non-planar artificial surface plasmon dielectric sensors, planar structures based on artificial surface plasmon dielectric sensors, such as metamaterial resonant rings, also exist. However, the input signal of these planar plasmon dielectric sensors is based on terahertz light excited by a quasi-optical system in free space. This process requires complex and precise instruments such as terahertz time-domain spectrometers, as well as stable environmental conditions, such as inert gases, temperature, and humidity. Therefore, the method for sensing and measuring dielectric materials in the terahertz frequency band using planar plasmon dielectric sensors is quite cumbersome.

[0032] To address the aforementioned problems, this invention provides a dielectric constant measurement device and method. This method measures the resonance peak curves of different samples by changing the geometric parameters of the metal unit of a waveguide dielectric sensor. By acquiring information on the center frequencies of the resonance peaks of different materials through these curves, the dielectric sensing function of the waveguide is realized. Furthermore, by integrating this waveguide dielectric sensor with a vector network analyzer, the structure of the artificial plasmonic waveguide dielectric sensor can be reused after structural improvements, enabling simple and efficient measurement of the dielectric constant of minute samples.

[0033] For example, such as Figure 1 The diagram shown is a top view of a waveguide dielectric sensor 100 provided in an embodiment of this application.

[0034] The waveguide dielectric sensor 100 can be based on an artificial surface plasmon waveguide.

[0035] In some embodiments, the waveguide dielectric sensor 100 comprises a first co-planar waveguide region 102 and a second co-planar waveguide region 108, a first transition region 103 and a second transition region 107, a first transmission region 104 and a second transmission region 106, a center unit region 105, and a substrate 200. The co-planar waveguide region 102 is provided with a metal line-shaped groove pointing to the center direction of the waveguide, and the first transition region 103 and the second transition region 107, the first transmission region 104 and the second transmission region 106, and the center unit region 105 are provided with a metal grid 110. The metal grid 110 comprises a plurality of metal units 111, which are periodically arranged along the central axis of the waveguide length direction. The length of the plurality of metal units 111 in the first transition region 103 and the second transition region 107 in the direction pointing to the center of the waveguide gradually increases, the length of the plurality of metal units 111 in the first transmission region 104 and the second transmission region 106 remains unchanged, and the length of the metal unit 112 at the center position of the center unit region 105 is greater than the length of the other metal units 111 in the center unit region 105. In order to adapt to the working range of the vector network analyzer, the length hl of the metal unit 112 at the center position of the center unit region 105 can be set to a range of 150 microns to 300 microns, for example. The length of the metal units in the first transmission region 104 and the second transmission region 106 and the center unit region 105 can determine the working frequency of the device, and the smaller the length, the higher the working frequency. Therefore, the working frequency of the entire device can be controlled by changing the length of the metal units 111 (except the metal unit 112 at the center position of the center unit region 105) in the first transmission region 104, the second transmission region 106, and the center unit region 105. In actual applications, the length of these metal units 111 can be set as needed, for example, the length of these metal units 111 can be set to any length greater than 0 microns and less than 100 microns.

[0036] As shown in the example, Figure 1 The metal grid array can comprise N metal grids (N is an odd number greater than 1), for example, the number of metal grids can be 41, but the embodiments of the present application do not limit this.

[0037] Unlike existing designs, the length hl of the metal unit 112 at the center position of the center unit region 105 is greater than the length of the other metal units 111 in the center unit region 105. By setting the length hl of the metal unit 112 to be greater than the length of the other metal units 111, the momentum of the propagating electromagnetic wave is mismatched, so that the electromagnetic wave is locally limited in the center unit region, the resonance curve produces a resonance peak, which can change the waveguide function from electromagnetic wave transmission to electromagnetic wave sensing, thereby realizing the measurement function of the material dielectric constant.

[0038] Exemplarily, as shown in FIG. 1, a side view structural schematic diagram of a waveguide dielectric sensor 100 provided by an embodiment of the present application is shown. Figure 2

[0039] In some embodiments, the upper surface of the substrate of the waveguide dielectric sensor 100 has a metal grid array periodically distributed along the length direction of the waveguide dielectric sensor, and the metal grid array includes a plurality of metal grids, each of which has a one-dimensional groove structure.

[0040] In some embodiments, the metal layer can be processed by photolithography process or additive manufacturing of integrated circuits, for example, the metal layer covering the first coplanar waveguide region 102 and the second coplanar waveguide region 108 is subjected to photolithography process or additive manufacturing process, so that the first coplanar waveguide region 102 and the second coplanar waveguide region 108 have a metal linear groove structure pointing to the center direction of the waveguide dielectric sensor; for another example, the metal layer covering the first transition region 103 and the second transition region 107, the first transmission region 104 and the second transmission region 106, and the central unit region 105 is subjected to photolithography process or additive manufacturing process, so that the transition region 103 and the second transition region 107, the transmission region 104 and the second transmission region 106, and the central unit region 105 have a one-dimensional groove structure, and the metal grid array of the one-dimensional groove structure is symmetrical along the width direction and the length direction of the substrate. The material of the metal layer covering the surface of the waveguide substrate can be a metal material with high conductivity and low loss, such as gold or copper. The material of the substrate can be a substrate material for semiconductor process, such as silicon or sapphire. The thickness of the metal layer and the substrate can be as small as microns under the premise of process permission, and the thickness is as thin as possible, which can be set to any length below 0.2 microns, such as the thickness of the metal layer can be set to 0.2 microns, and the thickness of the substrate can be set to 0.2 microns, but the embodiments of the present application are not limited thereto.

[0041] In order to better illustrate the dielectric sensing function of the waveguide provided by the embodiments of the present application, the principle of realizing the dielectric sensing function of the waveguide is introduced below by taking a specific waveguide dielectric sensor structure as an example.

[0042] Exemplarily, in a possible implementation manner, the substrate material of the waveguide dielectric sensor can be silicon, and the metal layer material can be gold. Exemplarily, as shown in FIG. 1, a side view structural schematic diagram of a waveguide dielectric sensor 100 provided by an embodiment of the present application is shown. Figure 3 ​As shown, the arrangement period p of the metal grid array in the waveguide dielectric sensor can be 100 microns, the slot width a of a single metal grid can be 35 microns, and the width g of the horizontal strip in a single metal grid can be 25 microns. The length h of the metal grids located at the first transmission region 104 and the second transmission region 106, and the other metal grids except the central position in the central unit region 105 can be 80 microns, the length hl of the metal grid located at the central position in the central unit region 105 can be set to 300 microns, the length of the metal grids located at the first transition region 103 and the second transition region 107 decreases uniformly from the center of the waveguide to the first port 101 and the second port 109 of the waveguide, respectively, the number of the metal grids in the first transition region 103 and the second transition region 107 can be set to 8, respectively, the length h of the metal grids decreases uniformly from the center of the waveguide to the first port 101 and the second port 109 of the waveguide, respectively, starting from 80 microns, decreasing by 10 microns each time, until the length h of the metal grid of the waveguide dielectric sensor reaches 10 microns.

[0043] In order to more clearly understand the feasibility and effect of measuring the dielectric constant of the material by increasing the length of the metal grid at the central position of the waveguide central unit region. Figure 4 The transmission spectrum of the waveguide dielectric sensor provided by the present application is shown when the length of the metal grid at the central position of the central unit region 105 is 80 microns and 300 microns, respectively.

[0044] In combination Figure 4 As shown, when the length of the metal grid 112 at the central position of the central unit region 105 is 80 microns, the transmission coefficient does not fluctuate significantly in the frequency range of 0THz-0.25THz, and the resonance curve presents a horizontal line, without obvious resonance peaks. When the length of the metal grid 112 at the central position of the central unit region 105 is 300 microns, the length of the metal grid is greater than that of the other metal grids located in the central unit region, which causes the momentum of the transmitted electromagnetic wave to be mismatched, so that the electromagnetic wave is localized in the central unit region, and the resonance curve fluctuates significantly in the range of 0.15THz-0.20THz. The transmission efficiency reaches a maximum value at a frequency of 0.175THz, indicating that a resonance peak is generated in the resonance curve, and the center frequency of the resonance peak is obtained, indicating that the function of the artificial surface plasmon changes from transmission to sensing, realizing the dielectric sensing function and providing a device basis for the method of measuring the dielectric constant of the dielectric material.

[0045] The artificial surface plasmon of the prior art has large structure size, and is limited in use. Compared with the prior art, the artificial surface plasmon waveguide provided by the application has a sensing function due to the change of the length of the center position metal grid 112 of the center unit region 105 of the waveguide dielectric sensor, the dielectric constant measurement method provided by the embodiment of the application has a simple instrument structure, and the requirement for environmental conditions is not strict, the sensing function can be realized under the above conditions, and the dielectric constant measurement method has the advantages of portability, light weight, easy integration, high sensitivity and the like, Figure 5 The sensitivity of the waveguide dielectric sensor measurement in the embodiment is demonstrated, and the sensitivity of the waveguide dielectric sensor is 27.4 MHz / RIU. Figure 5 The sensitivity of the waveguide dielectric sensor is 27.4 MHz / RIU.

[0046] In some embodiments, the dielectric constant measurement method provided by the embodiment of the application is specifically introduced as follows with reference to the accompanying drawings.

[0047] Figure 6A working flow diagram of a dielectric constant measurement system of a dielectric constant measurement device and method provided by embodiments of the present application is shown. The dielectric constant measurement device includes a waveguide dielectric sensor and a vector network analyzer. The vector network analyzer has a two-port network including a third port 201 and a fourth port 202. An electromagnetic wave signal is output from the third port 201 of the vector network analyzer through a coaxial cable. The electromagnetic wave signal is fed into a first port of the waveguide dielectric sensor 101. After passing through the waveguide dielectric sensor, the signal is output from a second port 109 of the waveguide and transmitted to the fourth port 202 of the vector network analyzer through a coaxial cable. In some embodiments, the vector network analyzer excites a transverse electromagnetic wave, which is fed into a first co-planar waveguide region 102 of the waveguide dielectric sensor from the first port 101 of the waveguide dielectric sensor. The transverse electromagnetic wave is converted into a transverse magnetic wave through a first transition region 103. Because surface plasmons propagate along the metal-dielectric surface and exponentially decay in the direction perpendicular to the wave propagation, the electromagnetic wave is strictly bound to the metal grid in the form of a surface wave and propagates through a first transmission region 104. Different lengths of metal grids 112 are introduced in a central unit region 105, causing the momentum of the propagating electromagnetic wave to be mismatched, so that the electromagnetic wave is localized in the central unit region. A resonance peak appears on the resonance curve, and the information of the resonance peak center frequency of different samples can be collected through the resonance peak curve. Therefore, the waveguide dielectric sensor is converted from a transmission function to a sensing function. The dielectric constant measurement device includes a vector network analyzer and a waveguide dielectric sensor. The vector network analyzer has a two-port network structure, which is represented by two symmetrical ports, namely a third port 201 and a fourth port 202. Each port can both excite a signal and accept a signal. Because of the two-port network characteristics of the vector network analyzer, the structure of the waveguide dielectric sensor integrated with the vector network analyzer also has a symmetrical structure. The two ports of the waveguide dielectric sensor are denoted as a first port 101 and a second port 109. When measuring the dielectric constant, an electromagnetic wave is excited through the third port 201 of the vector network analyzer and fed into the first port 101 of the waveguide dielectric sensor. After passing through the waveguide dielectric sensor, the electromagnetic wave flows out from the second port 109 of the waveguide dielectric sensor to the fourth port 202 of the vector network analyzer. The vector network analyzer receives the signal and obtains the transmission coefficient. Because of the two-port network structure of the vector network analyzer, the system has symmetry. Therefore, when an electromagnetic wave is excited through the second port 202 of the vector network analyzer, the third port 201 of the vector network analyzer receives the signal after passing through the waveguide dielectric sensor, and the transmission coefficient can also be obtained.The prior art for the measurement of the dielectric constant applied to the terahertz dielectric sensor has a planar geometry, such as a metamaterial resonant ring, but the input signal is based on the terahertz light excited by a quasi-optical system in free space, which requires complex and precise instruments, such as a terahertz time-domain spectrometer, and the measurement process is complicated, and the process requires stable environmental conditions, such as inert gas, temperature, humidity, etc. The dielectric constant measurement system of the present application has a relatively simple structure of the main instrument, and has a relatively low requirement for the environmental conditions, and the vector network analyzer has a relatively mature instrument platform, which can conveniently and quickly measure the dielectric constant of the sample.

[0048] Figure 7 The resonance peak shift of the resonance curve when the waveguide dielectric sensor carries samples with different dielectric constants is shown. When the waveguide dielectric sensor does not carry a sample, the dielectric constant is 1, and the resonance frequency is 0.173 THz. When the waveguide dielectric sensor carries samples with dielectric constants of 2 to 7, the resonance curve will be red-shifted with the increase of the dielectric constant of the measured sample. Therefore, by measuring the sample with a known dielectric constant, the corresponding resonance peak center frequency can be obtained, and the law of resonance peak frequency shift can be obtained. For a sample with an unknown dielectric constant, the position of the resonance peak center frequency can be obtained, and the frequency shift amount can be calculated by combining the resonance peak center frequency of the sample with a known dielectric constant. The law of frequency shift can be obtained, and the dielectric constant can be calculated by the vector network analyzer, thereby realizing the function of dielectric constant measurement.

[0049] Further, compared with the prior art, the waveguide dielectric sensor in the dielectric constant measuring device provided by the application is planarized and small in size, so that the dielectric constant of a sample with a size of micron level can be measured. When measuring the dielectric constant of a sample, for a solid sample with a small volume, a tablet is processed, and the tablet is placed in the center unit area 105 of the waveguide dielectric sensor; for a liquid sample, preferably, after being fixed by a hydrogel, the sample is placed in the center unit area 105 of the waveguide dielectric sensor; the waveguide dielectric sensor receives a transverse electromagnetic wave signal fed in by a third port of a vector network analyzer through a first port of the waveguide dielectric sensor; a transverse magnetic wave signal is output to a fourth port of the vector network analyzer through a second port of the waveguide dielectric sensor; a resonance curve corresponding to the sample to be measured is obtained, the frequency corresponding to the minimum transmission efficiency of the resonance curve is the center frequency of the resonance peak, and the center frequency of the resonance peak corresponds to the dielectric constant of the sample to be measured in a one-to-one manner; the dielectric constant of the sample to be measured is obtained according to the resonance peak of the sample to be measured and the resonance peak of a preset standard sample. The dielectric constant and the center frequency of the resonance peak of the plurality of standard samples are measured, and a plurality of center frequencies of the resonance peak when the dielectric constant of the plurality of standard samples changes are obtained, the center frequencies of the resonance peak and the dielectric constant of the standard sample have a one-to-one correspondence; the frequency offset rule is obtained from the correspondence; and the dielectric constant of the sample to be measured is calculated according to the frequency offset rule and the numerical value of the center frequency of the resonance peak of the sample to be measured.

[0050] Further, compared with the prior art, the waveguide dielectric sensor in the dielectric constant measuring device provided by the application is planarized and small in size, so that the dielectric constant of a sample with a size of micron level can be measured. When measuring the dielectric constant of a sample, for a solid sample with a small volume, a tablet is processed, and the tablet is placed in the center unit area 105 of the waveguide dielectric sensor; for a liquid sample, preferably, after being fixed by a hydrogel, the sample is placed in the center unit area 105 of the waveguide dielectric sensor; the waveguide dielectric sensor receives a transverse electromagnetic wave signal fed in by a third port of a vector network analyzer through a first port of the waveguide dielectric sensor; a transverse magnetic wave signal is output to a fourth port of the vector network analyzer through a second port of the waveguide dielectric sensor; a resonance curve corresponding to the sample to be measured is obtained, the frequency corresponding to the minimum transmission efficiency of the resonance curve is the center frequency of the resonance peak, and the center frequency of the resonance peak corresponds to the dielectric constant of the sample to be measured in a one-to-one manner; the dielectric constant of the sample to be measured is obtained according to the resonance peak of the sample to be measured and the resonance peak of a preset standard sample. The dielectric constant and the center frequency of the resonance peak of the plurality of standard samples are measured, and a plurality of center frequencies of the resonance peak when the dielectric constant of the plurality of standard samples changes are obtained, the center frequencies of the resonance peak and the dielectric constant of the standard sample have a one-to-one correspondence; the frequency offset rule is obtained from the correspondence; and the dielectric constant of the sample to be measured is calculated according to the frequency offset rule and the numerical value of the center frequency of the resonance peak of the sample to be measured.

[0051] Further, the working frequency of the dielectric constant measuring device and method provided by the application can be controlled by changing the geometric parameters of the metal grid in the center unit of the metal layer in the waveguide, which is convenient and flexible to design. Compared with the prior art, the dielectric constant measuring device and method can transmit microwave, millimeter wave and terahertz wave artificial surface plasmon electromagnetic waves by changing the size of the metal unit of the metal layer, which expands the application range of the artificial surface plasmon device and has good technical foresight.

[0052] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0053] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications 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 application, and should be included in the protection scope of the present application.

Claims

1. A permittivity measuring device, characterized by, The dielectric constant measurement device comprises a waveguide dielectric sensor and a vector network analyzer, the waveguide dielectric sensor comprises a first port and a second port, the vector network analyzer comprises a third port and a fourth port, the first port and the third port are connected, and the second port and the fourth port are connected. The waveguide dielectric sensor comprises a first transition region on the side of the first port, a second transition region on the side of the second port, a central unit region, the first transition region and the second transition region are symmetrical relative to the central position of the waveguide dielectric sensor, and the central unit region is located in the central region of the waveguide dielectric sensor, wherein: The first transition region, the second transition region and the central unit region respectively comprise a plurality of metal grids, the length of the metal grid located at the central position of the central unit region is greater than the length of other metal grids located in the central unit region; the length of the metal grid located in the first transition region uniformly decreases in the direction from the central position to the first port, and the length of the metal grid located in the second transition region uniformly decreases in the direction from the central position to the second port. The length of the metal grid located at the central position is set to any length greater than 150 microns and less than 300 microns.

2. The permittivity measuring device of claim 1, wherein, The waveguide dielectric sensor further comprises a first transmission region and a second transmission region, the first transmission region is located between the first port and the first transition region, and the second transmission region is located between the second port and the second transition region.

3. The permittivity measuring device of claim 1, wherein, The length of the metal grid located in the first transmission region and the second transmission region, and the length of the metal grid located in the central unit region except the central position are set to any length greater than 0 microns and less than 100 microns. The length of the metal grid located in the first transition region uniformly decreases in the direction from the central position to the first port until the length of the metal grid reaches a first threshold value, and the length of the metal grid located in the second transition region uniformly decreases in the direction from the central position to the second port until the length of the metal grid reaches the first threshold value.

4. The permittivity measuring apparatus according to claim 1 or 2, wherein The waveguide dielectric sensor comprises a substrate, the upper surface of the substrate has a periodic distribution of metal grid arrays along the length direction of the waveguide dielectric sensor, the metal grid array comprises a plurality of metal grids, and there is a one-dimensional groove structure between the metal grids.

5. A dielectric constant measuring apparatus as claimed in claim 1 or 2, characterized in that The material of the substrate of the waveguide dielectric sensor is silicon and / or sapphire.

6. The permittivity measuring device according to claim 5, wherein The material of the metal grid is gold and / or copper.

7. The permittivity measuring device according to claim 5, wherein The method is applied to the dielectric constant measurement device in any one of claims 1 to 7, the dielectric constant measurement device comprises a waveguide dielectric sensor and a vector network analyzer, and the method comprises:

8. A method of measuring the dielectric constant, characterized by, Placing a sample to be measured in the central unit region of the waveguide dielectric sensor; Receiving a transverse electromagnetic wave signal fed in by the third port of the vector network analyzer through the first port of the waveguide dielectric sensor; ​ The second port of the waveguide dielectric sensor outputs a transverse magnetic wave signal to a fourth port of the vector network analyzer; Obtaining a resonance curve corresponding to the sample to be measured, the center frequency of the resonance peak corresponding to the frequency at which the transmission efficiency of the resonance curve reaches a minimum value, the center frequency of the resonance peak corresponding to the dielectric constant of the sample to be measured in a one-to-one manner; According to the resonance peak of the sample to be measured and the resonance peak of the pre-set standard sample, the dielectric constant of the sample to be measured is obtained.

9. The method of claim 8, wherein, The dielectric constant and the center frequency of the resonance peak of the pre-set plurality of standard samples are measured, and a plurality of center frequencies of the resonance peak when the dielectric constant of the plurality of standard samples changes are obtained, the center frequency of the resonance peak and the dielectric constant of the standard sample having a one-to-one correspondence; The corresponding relationship is obtained from the corresponding relationship to obtain a frequency offset rule; According to the frequency offset rule and the numerical value of the center frequency of the resonance peak of the sample to be measured, the dielectric constant of the sample to be measured is calculated.

10. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 9. The computer program is executed by the processor to implement the method of any one of claims 8 or 9.

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