Dielectric constant measuring device and dielectric constant measuring system

Abstract

The present disclosure provides a dielectric constant measuring device and a measuring system, and belongs to the technical field of measurement. The present disclosure solves the problem of poor measurement accuracy of the existing dielectric constant measuring device. The dielectric constant measuring device comprises a first substrate and a second substrate arranged oppositely. The first substrate comprises a first substrate and a reference potential plate. The first substrate is provided with a receiving part. The receiving part is located at the position of the exposed reference potential plate. The second substrate comprises a second substrate and a first electrode plate. The first electrode plate is at least partially overlapped with the normal projection of the receiving part on the reference potential plate. The area of the normal projection of the receiving part is larger than the area of the normal projection of the first electrode plate. The measuring device further comprises a first sub-transmission structure and a second sub-transmission structure. The first sub-transmission structure is configured to transmit a microwave signal to the first electrode plate. The second sub-transmission structure is configured to transmit the microwave signal fed back by the first electrode plate.

Description

Technical Field

[0001] This disclosure belongs to the field of measurement technology, specifically relating to a dielectric constant measuring device and a dielectric constant measuring system. Background Technology

[0002] Liquid crystal materials, thanks to their unique dielectric properties and continuous tunability, have attracted widespread attention from researchers in the field of microwave communications, and their applications in the microwave frequency band are becoming increasingly widespread. Accurate measurement of the dielectric constant of liquid crystal materials in the microwave frequency band is crucial for the design and analysis of liquid crystal microwave devices.

[0003] There are three main types of existing methods for measuring the dielectric constant of liquid crystal materials in the microwave band: the perturbation method, the resonance method, and the phase shifter method. The perturbation method offers high measurement accuracy, but the measuring device is complex and expensive. The phase shifter method has a simpler measuring device than the perturbation method, but it requires very precise fabrication of components and necessitates the application of a strong static magnetic field to the liquid crystal material as a bias magnetic field, thus maintaining a relatively complex structure and high cost. The resonance method offers easy fabrication and low cost, but existing resonance method measuring devices have low sensitivity and cannot achieve accurate measurements. Summary of the Invention

[0004] This disclosure aims to at least solve one of the technical problems existing in the prior art, and to provide a dielectric constant measuring device and a dielectric constant measuring system.

[0005] In a first aspect, embodiments of this disclosure provide a dielectric constant measuring device, comprising: a first substrate and a second substrate disposed opposite to each other; wherein...

[0006] The first substrate includes a first substrate and a reference potential plate disposed on the side of the first substrate away from the second substrate, and a receiving portion is provided on the first substrate, wherein the location of the receiving portion exposes the reference potential plate.

[0007] The second substrate includes a second substrate and a first electrode plate disposed on the side of the second substrate close to the first substrate; the orthographic projection of the first electrode plate on the reference potential plate at least partially overlaps with the orthographic projection of the receiving portion on the reference potential plate; and the area of ​​the orthographic projection of the receiving portion is larger than the area of ​​the orthographic projection of the first electrode plate.

[0008] The measuring device further includes a transmission structure, which includes a first sub-transmission structure and a second sub-transmission structure; the first sub-transmission structure is configured to transmit a microwave signal to the first electrode plate, and the second sub-transmission structure is configured to transmit the microwave signal fed back from the first electrode plate.

[0009] Optionally, the receiving portion has multiple sides, and the orthographic projection of each side onto the reference potential plate at least partially overlaps with the orthographic projection of the first electrode plate onto the reference potential plate.

[0010] Optionally, the first electrode plate is circular in shape, and the receiving portion is polygonal in shape.

[0011] Optionally, the orthographic projection of the first electrode plate is tangent to the orthographic projection of at least one side of the receiving portion.

[0012] Optionally, the orthographic projection of the first electrode plate intersects with the orthographic projection of at least one side of the receiving portion at two points.

[0013] Optionally, the transmission structure is provided on the side of the second substrate facing away from the first electrode plate, and is electrically connected to the first electrode plate through a via.

[0014] Optionally, the transmission structure includes a first reference electrode, a second reference electrode, and a signal electrode disposed on the second substrate, wherein the signal electrode is disposed between the first reference electrode and the second reference electrode, and the signal electrode is electrically connected to the first electrode plate.

[0015] Secondly, embodiments of this disclosure provide a dielectric constant measurement system, including the dielectric constant measurement device described above.

[0016] Optionally, the dielectric constant measurement system also includes:

[0017] The power supply device includes a first voltage supply port and a second voltage supply port. The first voltage supply port is electrically connected to the reference potential plate of the measuring device, and the second voltage supply port is electrically connected to the first electrode plate of the measuring device. The first voltage signal provided by the first voltage port and / or the second voltage signal provided by the second voltage port are adjustable.

[0018] A microwave source connected to the transmission structure;

[0019] The vector network analyzer includes a first port and a second port. The first port is connected to the first sub-transmission structure, and the second port is connected to the output terminal of the second sub-transmission structure. The vector network analyzer is used to generate a first transmission coefficient curve when the voltage difference between the first voltage signal and the second voltage signal is zero, and to generate a second transmission coefficient curve when the voltage difference between the first voltage signal and the second voltage signal is greater than or equal to the saturation voltage value of the liquid crystal to be measured.

[0020] Optionally, the dielectric constant measurement system further includes a processor connected to the vector network analyzer, used to perform simulation and deduction to obtain the dielectric constant of the liquid crystal in the short axis direction corresponding to the first transmission coefficient curve and the dielectric constant of the liquid crystal in the long axis direction corresponding to the second transmission coefficient curve.

[0021] Optionally, the dielectric constant measurement system further includes a current isolation device disposed between the first port of the vector network analyzer and the first sub-transmission structure, and / or disposed between the second port of the vector network analyzer and the second sub-transmission structure. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a dielectric constant measuring device provided in an embodiment of the present disclosure;

[0023] Figure 2a A schematic diagram of another dielectric constant measuring device provided in this embodiment of the present disclosure;

[0024] Figure 2b for Figure 2a A cross-sectional view of the measuring device shown along the AA direction;

[0025] Figure 2c for Figure 2a A structural dimension diagram of the measuring device shown;

[0026] Figure 3 This is a schematic diagram of an exemplary dielectric constant measuring device;

[0027] Figure 4a A schematic diagram of the structure of another dielectric constant measuring device provided in this embodiment of the present disclosure;

[0028] Figure 4b for Figure 4a A structural dimension diagram of the measuring device shown;

[0029] Figure 5a A schematic diagram of the structure of another dielectric constant measuring device provided in this embodiment of the present disclosure;

[0030] Figure 5b for Figure 5a A structural dimension diagram of the measuring device shown;

[0031] Figure 6a A schematic diagram of the structure of another dielectric constant measuring device provided in this embodiment of the present disclosure;

[0032] Figure 6b for Figure 6a A structural dimension diagram of the measuring device shown;

[0033] Figure 7a A schematic diagram of the structure of another dielectric constant measuring device provided in this embodiment of the present disclosure;

[0034] Figure 7b for Figure 7a A structural dimension diagram of the measuring device shown;

[0035] Figure 8a A schematic diagram of the structure of another dielectric constant measuring device provided in this embodiment of the present disclosure;

[0036] Figure 8b for Figure 8a A structural dimension diagram of the measuring device shown;

[0037] Figure 9a A schematic diagram of the structure of another dielectric constant measuring device provided in this embodiment of the present disclosure;

[0038] Figure 9b for Figure 9a A structural dimension diagram of the measuring device shown;

[0039] Figure 10 This is a schematic diagram of a dielectric constant measurement system provided in an embodiment of the present disclosure. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0042] The first aspect provides a dielectric constant measuring device. Figure 1 This is a schematic diagram of the structure of a dielectric constant measuring device provided in an embodiment of the present disclosure, as shown below. Figure 1As shown, the dielectric constant measuring device includes a first substrate 1, a second substrate 2, and a transmission structure 3 arranged opposite to each other.

[0043] Specifically, the first substrate 1 includes a first substrate 12 and a reference potential plate 11. The reference potential plate 11 is disposed on the side of the first substrate 12 away from the second substrate 2, and a receiving portion 4 is provided on the first substrate 12, exposing the reference potential plate 11 at the location of the receiving portion 4. The second substrate 2 includes a second substrate 22 and a first electrode plate 21. The first electrode plate 21 is disposed on the side of the second substrate 22 close to the first substrate 12. The orthographic projection of the first electrode plate 21 on the first substrate 22 at least partially overlaps with the orthographic projection of the receiving portion 4 on the first substrate 12, and the area of ​​the orthographic projection of the receiving portion 4 is larger than the area of ​​the orthographic projection of the first electrode plate 21. The transmission structure 3 is disposed on the side of the second substrate 22 away from the first electrode plate 21, and the transmission structure 3 includes a first sub-transmission structure 31 and a second sub-transmission structure 32. The first sub-transmission structure 31 is configured to transmit microwave signals to the first electrode plate 21, and the second sub-transmission structure 32 is configured to transmit the microwave signals fed back from the first electrode plate 21.

[0044] The accommodating part 4 is used to accommodate the substance to be measured, which may include, but is not limited to, liquid crystal or inert gas. This embodiment is illustrated using liquid crystal as the substance to be measured.

[0045] The shape of the first electrode plate 21 can be selected according to the situation, such as a circle or a polygon, and is not specifically limited here. Similarly, the shape of the receiving part 4 can be selected according to the situation, such as a circle or a polygon, and is not specifically limited here.

[0046] The first substrate 12 and the second substrate 22 can be flexible substrates to improve the flexibility of the measuring device, enabling it to bend and bend, thus expanding its applicability. However, they are not limited to this; the first substrate 12 and the second substrate 22 can also be rigid, and the specific performance of the substrates can be determined according to the actual needs of the display product. Furthermore, the substrates can be single-layer or multi-layer structures. For example, the substrate may include multiple layers such as a polyimide layer, a buffer layer, and another polyimide layer stacked sequentially. The buffer layer can be made of materials such as silicon nitride or silicon oxide to achieve the effects of blocking water and oxygen and blocking alkaline ions. It should be noted that the structure of the substrate is not limited to this and can be determined according to actual needs.

[0047] The first sub-transmission structure 31 and the second sub-transmission structure 32 are respectively connected to the first electrode plate 21, which is configured to transmit microwave signals. The first sub-transmission structure 31 serves as the microwave signal input terminal of the first electrode plate 21, and thus the microwave signal input terminal of the entire measuring device, for receiving microwave signals. The second sub-transmission structure 32 serves as the microwave signal output terminal of the first electrode plate 21, and thus the microwave signal output terminal of the entire measuring device, for outputting microwave signals. The first sub-transmission structure 31 and the second sub-transmission structure 32 can be connected to the first electrode plate 21 in various ways; for example, they can be connected via electrical wires. In this embodiment, the first sub-transmission structure 31 and the second sub-transmission structure 32 are electrically connected to the first electrode plate 21 through vias passing through the second substrate 21.

[0048] In the measuring device provided in this disclosure, the reference potentiometer 11 can be configured to receive a first voltage signal, and the first electrode plate 21 can be configured to receive a second voltage signal. The first voltage signal and / or the second voltage signal are adjustable, thereby making the voltage difference between the first voltage signal and the second voltage signal adjustable.

[0049] When the dielectric constant of a liquid crystal is measured using the above-mentioned measuring device, the liquid crystal to be measured is injected into the receiving part 4 of the measuring device to form a liquid crystal layer.

[0050] After the liquid crystal layer is formed by liquid crystal injection, measurement can begin. During measurement, the first sub-transmission structure 31 transmits microwave signals to the first electrode plate 21. The microwave signals can couple with the first electrode plate, generating resonance. Simultaneously, the voltage difference between the reference potential plate 11 and the first electrode plate 21 is adjusted, i.e., the voltage difference between the first voltage signal and the second voltage signal is adjusted, causing a change in the equivalent dielectric constant of the liquid crystal layer. Different equivalent dielectric constants of the liquid crystal layer will have different effects on the resonance in the first electrode plate 21. This effect can be reflected by the transmission coefficient curve of the microwave output by the second sub-output structure 32. Based on the transmission coefficient curve, the dielectric constant of the liquid crystal can be obtained, thus realizing the measurement of the dielectric constant of the liquid crystal in the microwave frequency band.

[0051] Simulation results show that the above-mentioned measuring device exhibits extremely high sensitivity when measuring the dielectric constant of liquid crystals, and can be adjusted to different test frequency bands, demonstrating strong scalability. Compared to existing measuring devices, the measuring device provided in this embodiment does not require a magnetic field biasing mechanism, thus it is compact, simple in structure, and can be manufactured using standardized semiconductor processes, eliminating the need for subsequent precision assembly of individual components, thereby reducing costs. Furthermore, by setting the area of ​​the orthographic projection of the receiving portion 4 to be larger than the area of ​​the orthographic projection of the first electrode plate 21, the influence of the edge electric field formed by the reference potential plate 11 and the first electrode plate 21 on the deflection of the liquid crystal can be reduced, thereby further improving the measurement accuracy of the measuring device.

[0052] In some embodiments, the reference potential plate 11 can be grounded, that is, the first voltage signal connected to the reference potential plate 11 is the ground voltage. This can fix the potential of the reference potential plate 11. When adjusting the voltage difference between the reference potential plate 11 and the first electrode plate 21, only the second voltage signal connected to the first electrode plate 21 needs to be adjusted, simplifying the operation.

[0053] In some embodiments, the receiving portion 4 may have multiple sides, each side whose orthographic projection on the reference electrode plate 11 at least partially overlaps with the orthographic projection of the first electrode plate 21 on the reference electrode plate 11. For example, the orthographic projection of the first electrode plate 21 is tangent to the orthographic projection of at least one side of the receiving portion 4; or the orthographic projection of the first electrode plate 21 and the orthographic projection of at least one side of the receiving portion 4 have two intersection points.

[0054] In this embodiment, the orthographic projection of the first electrode plate 21 is tangent to the orthographic projection of at least one side of the receiving portion 4, or the orthographic projection of the first electrode plate 21 and the orthographic projection of at least one side of the receiving portion 4 have two intersection points. In essence, the area of ​​the orthographic projection of the receiving portion 4 is set to be larger than the area of ​​the orthographic projection of the first electrode plate 21. Therefore, the influence of the edge electric field formed by the reference potential plate 11 and the first electrode plate 21 on the deflection of the liquid crystal can be reduced, thereby improving the measurement accuracy of the measuring device.

[0055] In the above-mentioned measuring device, the structural design of the first electrode plate 21 and the receiving part 4 has a significant impact on the measurement accuracy. This will be explained below with reference to some specific embodiments.

[0056] Example 1:

[0057] Figure 2a This is a schematic diagram of another dielectric constant measuring device provided in an embodiment of this disclosure. Figure 2b for Figure 2a The cross-sectional view of the measuring device shown is along the AA direction. This embodiment uses a circular first electrode plate 21 and a square receiving portion 4 as an example for explanation. Figure 2aand Figure 2b As shown, the dielectric constant measuring device includes a first substrate 100, a second substrate 200, and a transmission structure 300 disposed opposite to each other. The first substrate 100 includes a first substrate 102 and a reference potential plate 101. The reference potential plate 101 is disposed on the side of the first substrate 102 opposite to the second substrate 200, and a receiving portion 400 is provided on the first substrate 102, exposing the reference potential plate 101 at the location of the receiving portion 400. The second substrate 200 includes a second substrate 202 and a first electrode plate 201. The first electrode plate 201 is disposed on the side of the second substrate 202 close to the first substrate 102. The orthographic projection of the first electrode plate 201 on the reference potential plate 101 at least partially overlaps with the orthographic projection of the receiving portion 400 on the reference potential plate 101. The transmission structure 300 is disposed on the side of the second substrate 202 away from the first electrode plate 201. The transmission structure 300 includes a first sub-transmission structure 301 and a second sub-transmission structure 302. The first sub-transmission structure 301 is configured to transmit a microwave signal to the first electrode plate 201. The second sub-transmission structure 302 is configured to transmit the microwave signal fed back from the first electrode plate 201. The area of ​​the orthographic projection of the receiving portion 400 is larger than the area of ​​the orthographic projection of the first electrode plate 201.

[0058] In this embodiment, as Figure 2c As shown, the diameter of the first electrode plate 201 is selected as 20 μm, and the side length of the receiving part 400 is also selected as 20 μm. That is, the orthographic projection of each side of the receiving part 400 on the reference potential plate 101 is tangent to the orthographic projection of the first electrode plate 201 on the reference potential plate 101.

[0059] In this embodiment, the liquid crystal to be tested is injected into the receiving portion 400, and resonance is generated in the first electrode plate 201 by electromagnetic waves to obtain the TM of the resonant structure. 110 The resonant frequency f corresponding to the mode 110 Therefore, the measured value of the dielectric constant of the liquid crystal can be calculated according to the following formula (1).

[0060]

[0061] Where, ε r χ′ is the dielectric constant of the liquid crystal; c is the speed of light in vacuum; a is the radius of the first electrode plate; h is the thickness of the liquid crystal layer. mn J is an m-order Bessel function m The nth root value corresponding to the zero of (x). Different transmission modes correspond to different χ′. mn and f mn0 , and χ′ mn The value can be obtained by consulting the Bessel function table. The first four resonant modes of this resonant cavity are TM. 110 TM210 TM 010 TM 310 For TM 110 The modulus, obtained from the table, is χ′. 11 =1.8412. Resonant Mode TM 110 The resonant frequency at that time is f 110 .

[0062] The measuring device was simulated to obtain the resonant frequencies f of multiple liquid crystals. 110 The measured values ​​of the dielectric constants of multiple liquid crystals were calculated using formula (1). Compared with the actual values ​​of the dielectric constants of the multiple liquid crystals, the result showed an error of <3%.

[0063] Figure 3 This is a schematic diagram of an exemplary dielectric constant measuring device. Figure 3 The measuring device shown is Figure 2a The only difference in the measuring device shown is that the area of ​​the orthographic projection of the receiving part 400 is smaller than the area of ​​the orthographic projection of the first electrode plate 201.

[0064] Figure 3 The simulation results of the measuring device are the theoretical values ​​of the dielectric constant calculated by formula (1) when the liquid crystal is at different dielectric constants, and compared with the measured values ​​of the dielectric constant, with an error of <10%.

[0065] In summary, it can be seen that Figure 2a The measurement error of the measurement structure shown is compared to Figure 3 The measurement error of the measuring device shown is greatly reduced. The essential reason is that the area of ​​the orthographic projection of the receiving part 400 is larger than the area of ​​the orthographic projection of the first electrode plate 201. Therefore, the influence of the edge electric field formed by the reference potential plate 101 and the first electrode plate 201 on the deflection of the liquid crystal can be reduced, thereby further improving the measurement accuracy of the measuring device.

[0066] Example 2:

[0067] Figure 4a This is a schematic diagram of the structure of another dielectric constant measuring device provided in an embodiment of the present disclosure. Figure 4a The measuring device shown is Figure 2a The difference in the measuring device shown is that the shape of the receiving part 400 is a regular pentagon, such as... Figure 4b As shown, the side length of the regular pentagonal receiving portion 400 is 13.4 μm, and the orthographic projection of the side of the regular pentagonal receiving portion 400 onto the reference potentiometer plate 101 and the orthographic projection of the circular first electrode plate 201 onto the reference potentiometer plate 101 have two intersection points.

[0068] right Figure 4b The measurement device shown was used for simulation to obtain the resonant frequencies f of multiple liquid crystals. 110The measured values ​​of the dielectric constants of multiple liquid crystals were calculated using formula (1). Compared with the actual values ​​of the dielectric constants of the multiple liquid crystals, the result showed an error of <1.2%. It can be seen that in this embodiment, the area of ​​the orthographic projection of the receiving portion 400 is larger than the area of ​​the orthographic projection of the first electrode plate 201, which can significantly improve the error range between the measured value and the theoretical value.

[0069] Example 3:

[0070] Figure 5a This is a schematic diagram of the structure of another dielectric constant measuring device provided in an embodiment of this disclosure. Figure 5b for Figure 5a A structural dimension diagram of the measuring device shown is as follows: Figure 5b The measuring device shown is Figure 4b The difference in the measuring device shown is that the side length of the regular pentagonal receiving part is 14.5 μm, that is, the orthographic projection of the side of the receiving part is tangent to the orthographic projection of the first electrode plate.

[0071] right Figure 5b The measurement device shown was used for simulation to obtain the resonant frequencies f of multiple liquid crystals. 110 The measured values ​​of the dielectric constants of multiple liquid crystals were calculated using formula (1). Compared with the actual values ​​of the dielectric constants of the multiple liquid crystals, the result showed an error of <1%. It can be seen that in this embodiment, the area of ​​the orthographic projection of the receiving portion 400 is larger than the area of ​​the orthographic projection of the first electrode plate 201, and the orthographic projection of the side of the receiving portion 400 is tangent to the orthographic projection of the first electrode plate 201. Figure 4b Compared to the measuring device shown, the error range between the measured value and the theoretical value can be further significantly improved.

[0072] Example 4;

[0073] Figure 6a This is a schematic diagram of the structure of another dielectric constant measuring device provided in an embodiment of this disclosure. Figure 6b for Figure 6a A structural dimension diagram of the measuring device shown. Figure 6b The measuring device shown is Figure 5b The difference in the measuring device shown is that the side length of the regular pentagonal receiving part is 15.7 μm, that is, the orthographic projection of the side of the receiving part 400 does not intersect or tangent with the orthographic projection of the first electrode plate 201.

[0074] right Figure 6b The measurement device shown was used for simulation to obtain the resonant frequencies f of multiple liquid crystals. 110 The measured values ​​of the dielectric constants of multiple liquid crystals were calculated using formula (1). Compared with the actual values ​​of the dielectric constants of the multiple liquid crystals, the result showed an error of <1%. It can be seen that... Figure 5bCompared to the measuring device shown, in the measuring device provided in this embodiment, after the orthographic projection of the receiving portion 400 is tangent to the orthographic projection of the first electrode plate 201, even with further extension, the error range between the measured value and the theoretical value cannot be further improved. Therefore, the tangency of the orthographic projection of the receiving portion 400 to the orthographic projection of the first electrode plate 201 is a critical point. Therefore, in practical applications, selecting a measuring device with a structure where the orthographic projection of the receiving portion 400 is tangent to the orthographic projection of the first electrode plate 201 can save materials and reduce manufacturing costs.

[0075] Example 5:

[0076] Figure 7a This is a schematic diagram of the structure of another dielectric constant measuring device provided in an embodiment of this disclosure. Figure 7a The measuring device shown is Figure 6a The only difference in the measuring device shown is that the shape of the receiving part is a regular hexagon, such as Figure 7b As shown, the side length of the regular hexagon is 11.6 μm, and the orthographic projection of the side of the receiving portion 400 of the regular hexagon is tangent to the orthographic projection of the first electrode plate 201.

[0077] right Figure 7b The measurement device shown was used for simulation to obtain the resonant frequencies f of multiple liquid crystals. 110 The measured values ​​of the dielectric constants of multiple liquid crystals were calculated using formula (1). Compared with the actual values ​​of the dielectric constants of the multiple liquid crystals, the result showed an error of <1.2%. It can be seen that in this embodiment, the orthographic projection of the side of the hexagonal receiving portion 400 is tangent to the orthographic projection of the first electrode plate 201. Figure 6a The measuring device shown uses a regular pentagonal receiving part 400 whose side projection is tangent to the front projection of the first electrode plate 201, which can achieve the same technical effect of reducing error.

[0078] Example 6:

[0079] Figure 8a This is a schematic diagram of the structure of another dielectric constant measuring device provided in an embodiment of this disclosure. Figure 8a The measuring device shown is Figure 6a The only difference in the measuring device shown is that the shape of the receiving part is a regular heptagon, such as Figure 8b As shown, the side length of the regular heptagon is 11.6 μm.

[0080] right Figure 8b The measurement device shown was used for simulation to obtain the resonant frequencies f of multiple liquid crystals. 110The measured values ​​of the dielectric constants of multiple liquid crystals were calculated using formula (1). Compared with the actual values ​​of the dielectric constants of the multiple liquid crystals, the result showed an error of <1.2%. It can be seen that in this embodiment, the orthographic projection of the side of the heptagonal receiving portion 400 is tangent to the orthographic projection of the first electrode plate 201. Figure 6a The measuring device shown uses a regular pentagonal receiving part 400 whose side projection is tangent to the front projection of the first electrode plate 201, which can achieve the same technical effect of reducing error.

[0081] It should be noted that the shape and size of the receiving portion 400, the shape and size of the first electrode plate 201, and the dimensions of each component described above are merely illustrative examples. It is understood that the shape and size of the receiving portion 400 and the first electrode plate 201 can also be of other types. Furthermore, the shape and size of the receiving portion 400, the first electrode plate 201, and the dimensions of each component described above do not constitute a limitation of this disclosure. The shape and size of the receiving portion 400 and the first electrode plate 201 can be selected according to the circumstances, as long as the area of ​​the orthographic projection of the receiving portion 400 is set to be greater than the area of ​​the orthographic projection of the first electrode plate 201.

[0082] For example, Figure 9a This is a schematic diagram of the structure of another dielectric constant measuring device provided in an embodiment of this disclosure. Figure 9b for Figure 9a The diagram shows one structural dimension of the measuring device. Figure 9a and Figure 9b The measuring device shown has a circular housing 400, and the area of ​​the orthographic projection of the circular housing 400 is set to be larger than the area of ​​the orthographic projection of the circular first electrode plate 201.

[0083] right Figure 9b The measurement device shown was used for simulation to obtain the resonant frequencies f of multiple liquid crystals. 110 The measured values ​​of the dielectric constants of multiple liquid crystals were calculated using formula (1). Compared with the actual values ​​of the dielectric constants of the multiple liquid crystals, the result showed an error of <1%. It can be seen that in this embodiment, using a circular receiving portion 400 can still achieve the technical effect of reducing errors and improving measurement accuracy.

[0084] In some embodiments, such as Figure 2aAs shown, the first transmission structure 301 includes a signal electrode 3011, a first reference electrode 3012, and a second reference electrode 3013 disposed on the second substrate 202. The signal electrode 3011 is disposed between the first reference electrode 3012 and the second reference electrode 3013, i.e., the first transmission structure 301 is a CPW structure. The signal electrode 3011 is electrically connected to the first electrode plate 201. Similarly, the second transmission structure 302 has the same structure as the first transmission structure 301, and will not be described in detail here.

[0085] Secondly, embodiments of this disclosure provide a dielectric constant measurement system, such as... Figure 10 As shown, the dielectric constant measurement system includes a liquid crystal dielectric constant measuring device, a power supply device 500, a microwave source 600, a vector network analyzer 700, and a processor 800.

[0086] Specifically, the power supply device 500 includes a first voltage supply port 501 and a second voltage supply port 502. The first voltage supply port is electrically connected to the reference potential plate 11 of the measuring device, and the second voltage supply port 502 is electrically connected to the first electrode plate 21 of the measuring device. The first voltage signal provided by the first voltage port 501 and / or the second voltage signal provided by the second voltage port 502 are adjustable. The microwave source 600 is connected to the transmission structure 3. The vector network analyzer 700 includes a first port and a second port. The first port is connected to the first sub-transmission structure 31, and the second port is connected to the output terminal of the second sub-transmission structure 32. The vector network analyzer 700 is used to generate a first transmission coefficient curve when the voltage difference between the first voltage signal and the second voltage signal is zero, and to generate a second transmission coefficient curve when the voltage difference between the first voltage signal and the second voltage signal is greater than or equal to the saturation voltage value of the liquid crystal to be measured. The processor 800 is connected to the vector network analyzer 700. The processor 800 is used to perform simulation deduction to obtain the dielectric constant of the liquid crystal in the short axis direction corresponding to the first transmission coefficient curve and the dielectric constant of the liquid crystal in the long axis direction corresponding to the second transmission coefficient curve.

[0087] In this embodiment, the liquid crystal dielectric constant measuring device is the liquid crystal dielectric constant measuring device provided in this disclosure, which has the advantages of high measurement sensitivity and accuracy, simple structure and low cost.

[0088] In some embodiments, the dielectric constant measurement system further includes a current isolation device 900, which is disposed between the first port of the vector network analyzer and the first subtransmission structure 31 (e.g., Figure 10 ), and / or current isolation device 900 is disposed between the second port of vector network analyzer 700 and the second subtransmission 32 structure (not shown in the figure).

[0089] In this embodiment, by placing the current isolation device 900 between the first port of the vector network analyzer 700 and the first sub-transmission structure 31, and / or placing the current isolation device 900 between the second port of the vector network analyzer 700 and the second sub-transmission structure 32, the current can be isolated to avoid damage to the vector network analyzer 700.

[0090] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A dielectric constant measuring device, characterized in that, include: A first substrate and a second substrate are disposed opposite to each other; wherein... The first substrate includes a first substrate and a reference potential plate disposed on the side of the first substrate away from the second substrate. A receiving portion is provided on the first substrate, the sidewall of the receiving portion is formed by the first substrate, and the reference potential plate is exposed at the location of the receiving portion. The second substrate includes a second substrate and a first electrode plate disposed on the side of the second substrate close to the first substrate; the orthographic projection of the first electrode plate on the reference potential plate at least partially overlaps with the orthographic projection of the receiving portion on the reference potential plate, and the area of ​​the orthographic projection of the receiving portion is larger than the area of ​​the orthographic projection of the first electrode plate; the first electrode plate is embedded in the receiving portion, and at least a portion of the edge of the first electrode plate has a gap with the edge of the receiving portion. The measuring device further includes a transmission structure, which includes a first sub-transmission structure and a second sub-transmission structure; the first sub-transmission structure is configured to transmit a microwave signal to the first electrode plate, and the second sub-transmission structure is configured to transmit the microwave signal fed back from the first electrode plate.

2. The dielectric constant measuring device according to claim 1, characterized in that, The receiving portion has multiple sides, and the orthographic projection of each side onto the reference potential plate at least partially overlaps with the orthographic projection of the first electrode plate onto the reference potential plate.

3. The dielectric constant measuring device according to claim 2, characterized in that, The first electrode plate is circular in shape, and the receiving portion is polygonal in shape.

4. The dielectric constant measuring device according to claim 3, characterized in that, The orthographic projection of the first electrode plate is tangent to the orthographic projection of at least one side of the receiving portion, or the orthographic projection of the first electrode plate and the orthographic projection of at least one side of the receiving portion have two intersection points.

5. The dielectric constant measuring device according to any one of claims 1-4, characterized in that, The transmission structure has a second substrate on the side opposite to the first electrode plate, and is electrically connected to the first electrode plate through a via.

6. The dielectric constant measuring device according to claim 5, characterized in that, The transmission structure includes a first reference electrode, a second reference electrode, and a signal electrode disposed on the second substrate. The signal electrode is disposed between the first reference electrode and the second reference electrode, and is electrically connected to the first electrode plate.

7. A dielectric constant measurement system, characterized in that, Includes the dielectric constant measuring device as described in any one of claims 1-6.

8. The dielectric constant measurement system according to claim 7, characterized in that, Also includes: The power supply device includes a first voltage supply port and a second voltage supply port. The first voltage supply port is electrically connected to the reference potential plate of the measuring device, and the second voltage supply port is electrically connected to the first electrode plate of the measuring device. The first voltage signal provided by the first voltage supply port and / or the second voltage signal provided by the second voltage supply port are adjustable. A microwave source connected to the transmission structure; The vector network analyzer includes a first port and a second port. The first port is connected to the first sub-transmission structure, and the second port is connected to the output terminal of the second sub-transmission structure. The vector network analyzer is used to generate a first transmission coefficient curve when the voltage difference between the first voltage signal and the second voltage signal is zero, and to generate a second transmission coefficient curve when the voltage difference between the first voltage signal and the second voltage signal is greater than or equal to the saturation voltage value of the liquid crystal to be measured.

9. The dielectric constant measurement system according to claim 8, characterized in that, Also includes: The processor connected to the vector network analyzer is used to perform simulation and deduction to obtain the dielectric constant of the liquid crystal in the short axis direction corresponding to the first transmission coefficient curve and the dielectric constant of the liquid crystal in the long axis direction corresponding to the second transmission coefficient curve.

10. The dielectric constant measurement system according to claim 8, characterized in that, It also includes a current isolation device, which is disposed between the first port of the vector network analyzer and the first sub-transmission structure, and / or disposed between the second port of the vector network analyzer and the second sub-transmission structure.

Images