CN114373580A - Flexible transmission line and application thereof - Google Patents
Flexible transmission line and application thereof Download PDFInfo
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- CN114373580A CN114373580A CN202111540441.7A CN202111540441A CN114373580A CN 114373580 A CN114373580 A CN 114373580A CN 202111540441 A CN202111540441 A CN 202111540441A CN 114373580 A CN114373580 A CN 114373580A
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Images
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B11/00—Communication cables or conductors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
Landscapes
- Structure Of Printed Boards (AREA)
Abstract
The invention discloses a flexible transmission line and application thereof, wherein the flexible transmission line comprises a signal layer, a substrate layer and a ground layer which are sequentially stacked, the signal layer is in contact with the substrate layer, the signal layer is made of at least one of gold, silver or copper, the substrate layer comprises a liquid crystal polymer film layer, and the liquid crystal polymer film layer is a liquid crystal orientation film formed by curing raw materials comprising a liquid crystal polymer and a photoinitiator. The liquid crystal polymer film layers with different dielectric constants are obtained by adjusting the orientation of the liquid crystal polymer by utilizing the polymer alignment property of the liquid crystal polymer, so that the flexible transmission lines with different dielectric constants are further prepared.
Description
Technical Field
The invention relates to the field of materials, in particular to a flexible transmission line and application thereof.
Background
In recent years, communication technology is rapidly developed, and in order to meet the demand of increasing communication rate, the working frequency band of flexible electronic equipment is higher and higher, and from the frequency band of several GHz in the 4G era, the working frequency band is gradually extended to the frequency bands of dozens of GHz and hundreds of GHz of millimeter waves and terahertz waves, as a key way for signal transmission, a transmission line on a printed circuit board in the flexible electronic equipment is a main part for realizing high-frequency signal transmission. At present, the global demand for high-speed communication application is increasing day by day, and high-speed and low-loss novel transmission lines are required to be researched in various '5G industries' such as automatic driving, telemedicine and smart cities with high precision and low delay. High speed, low loss transmission lines require that the dielectric material of the transmission line be characterized by a low dielectric constant (Dk) and a low dielectric loss (Df). The transmission line based on the glass fiber epoxy resin plate has very serious signal loss in high-frequency transmission, and is completely inapplicable to the current high-speed high-frequency communication.
At present, materials with good application prospects in the 5G communication technology mainly include: polytetrafluoroethylene (PTFE), Liquid Crystal Polymer (LCP), modified polyphenylene (MPPE), Polyimide (PI), and the like. The PTFE film is not suitable for manufacturing ultra-thin circuit boards because of its low elastic modulus, difficult processing into a film with a small thickness, and high linear expansion coefficient. Further, PTFE has a weak adhesion to elements such as metal conductors. The MPPE surface substrate has excellent dielectric property, but is limited by heat resistance and dimensional stability in practical application, and cannot meet the processing requirement of parts in many cases. The PI material has a large dielectric constant, a large loss factor and poor reliability, so that a Flexible Printed Circuit (FPC) made of the PI material has serious signal loss in high-frequency end transmission, and cannot adapt to the current 5G communication application. LCP has good thermal stability, dielectric property, radiation resistance, corrosion resistance and electrical insulation property, and has good application prospect in the 5G field.
In order to solve the problem of serious signal loss in the high-frequency transmission process, a substrate material with low signal loss in the high-frequency transmission is needed.
Disclosure of Invention
In order to overcome the problems of the prior art, an object of the present invention is to provide a flexible transmission line.
The invention also aims to provide an application of the flexible transmission line in 5G communication materials or circuit boards.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the invention provides a flexible transmission line, which comprises a signal layer, a base material layer and a ground layer which are sequentially stacked, wherein the signal layer is in contact with the base material layer; the signal layer is made of at least one of copper, gold or silver; the substrate layer comprises a liquid crystal polymer film layer, and the liquid crystal polymer film layer is a liquid crystal orientation film formed by curing raw materials comprising a liquid crystal polymer and a photoinitiator.
Preferably, the signal layer has at least one of a strip shape and a sheet shape; further preferably, the signal layer is sheet-shaped.
Preferably, the signal layer is composed of more than one conductive metal sheet, all the conductive metal sheets are located in the same horizontal plane and all the conductive metal sheets are in contact with the base material layer, and the number of the conductive metal sheets can be selected according to actual use requirements. The conductive metal sheet is at least one of copper foil, gold foil and silver foil.
Preferably, the signal layer, the substrate layer and the grounding layer are formed by laminating adhesives.
Preferably, the flexible transmission line is a 5G flexible transmission line; further preferably, the flexible transmission line is a reconfigurable 5G flexible transmission line.
Preferably, the curing conditions are ultraviolet light curing; further preferably, the curing conditions are 365nm ultraviolet light induced curing.
Preferably, the material of the signal layer is at least one of copper, silver and gold.
Preferably, the material of the ground layer is at least one of copper, silver and gold.
Preferably, the liquid crystal polymer comprises at least one of E7 liquid crystal, 5CB liquid crystal, RM257 liquid crystal. Further preferably, the liquid crystal polymer comprises RM 257. RM257(HCCH, Jiangsu Hecheng) is a white powdery solid at room temperature, and has the following molecular structural formula:
preferably, the photoinitiator comprises at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1-hydroxycyclohexyl phenyl ketone. The 2-hydroxy-2-methyl-1-phenyl-1-propanone, also known as 1173 photoinitiator, has the following formula:
the 1-hydroxycyclohexyl phenyl ketone is also known as 184 photoinitiator.
Preferably, the mass ratio of the liquid crystal polymer to the photoinitiator is (40-50) to 1; further preferably, the mass ratio of the liquid crystal polymer to the photoinitiator is (42-48) to 1; further preferably, the mass ratio of the liquid crystal polymer to the photoinitiator is (45-48): 1.
Preferably, the liquid crystal polymer film layer is prepared by the following preparation method, which comprises the following steps:
s1: mixing the liquid crystal polymer and the photoinitiator in a dark place;
s2: and (4) adding the product obtained in the step S1 into an oriented liquid crystal box, and carrying out photoinitiated curing to obtain the liquid crystal polymer film layer.
Preferably, the mixing temperature of the light-shielding mixing is 80-120 ℃; further preferably, the mixing temperature of the light-shielding mixing is 90-110 ℃; still further preferably, the mixing temperature for the mixing with exclusion of light is 100 ℃.
Preferably, the step S1 is specifically: adding a liquid crystal polymer and a photoinitiator into a brown reagent bottle, putting the brown reagent bottle into a small beaker filled with silicone oil, heating the small beaker to 80-120 ℃ by adopting a water bath heating method, and stirring for 10-30 min to uniformly mix the liquid crystal polymer and the photoinitiator.
Preferably, the step S2 is specifically: adding the product obtained in the step S1 into an orientation liquid crystal box which is insulated at the temperature of 80-120 ℃, and using 2-4 mW/cm2Curing for 2-8 min by ultraviolet light with the wavelength of 360-370 nm to prepare the liquid crystal polymer film layer; further preferably, the step S2 specifically includes: the product of step S1 was added to an orientation cell incubated at 100 ℃ using 3mW/cm at 95 ℃2And 365nm ultraviolet light initiates curing for 5min to prepare the liquid crystal polymer film layer.
Preferably, the thickness of the liquid crystal polymer film layer is 200-400 μm; further preferably, the thickness of the liquid crystal polymer film layer is 200-350 μm; still more preferably, the thickness of the liquid crystal polymer film layer is 200 to 300 μm.
Preferably, the angle between the tilt angle of the liquid crystal molecules of the liquid crystal polymer and the horizontal direction is 0 ° to 90 °. The liquid crystal polymer film layers with different dielectric constants are obtained by changing the arrangement orientation of the liquid crystal molecules of the liquid crystal polymer in the substrate layer, and then the transmission line with adjustable transmission speed is obtained.
Preferably, the thickness of the signal layer and the thickness of the grounding layer are both 60-150 μm; further preferably, the thickness of the signal layer and the thickness of the grounding layer are both 70-130 μm; still further preferably, the thickness of the signal layer and the ground layer is 90-110 μm.
Preferably, the width of the signal layer is 0.5-1.5 mm; further preferably, the width of the signal layer is 0.8-1.5 mm; further preferably, the width of the signal layer is 1-1.2 mm.
Preferably, a first cementing layer is further arranged between the signal layer and the base material layer; and a second cementing layer is also arranged between the substrate layer and the grounding layer.
Preferably, the materials of the first adhesive layer and the second adhesive layer are hot-melt adhesives.
Preferably, the hot-melt adhesive comprises at least one of a polyolefin hot melt adhesive, a polyester hot melt adhesive, a polyamide hot melt adhesive and a polyurethane hot melt adhesive.
Preferably, the dielectric constant of the liquid crystal polymer film layer is 2.7-3.3.
Preferably, the insertion loss of the flexible transmission line at 5-6GHz is-0.2 dB to-0.3 dB,
the second aspect of the invention provides an application of the flexible transmission line provided by the first aspect of the invention in a 5G communication material or a circuit board.
The invention has the beneficial effects that: the liquid crystal polymer film layers with different dielectric constants are obtained by adjusting the orientation of the liquid crystal polymer by utilizing the polymer alignment property of the liquid crystal polymer, so that the flexible transmission lines with different dielectric constants are further prepared.
Specifically, the method comprises the following steps:
according to the invention, the liquid crystal polymer thin film layer is formed in the orientation liquid crystal box through photo-initiated curing of the RM257 and 1173 photoinitiators, the prepared liquid crystal polymer thin film layer has orientation, the dielectric constant of the liquid crystal polymer thin film layer can be adjusted by adjusting the molecular orientation of the liquid crystal polymer, the purpose of changing the transmission speed of the flexible transmission line is realized by adjusting the dielectric constant of the flexible transmission line, the performance of the flexible transmission line is further adjusted according to different use requirements, and the application range is wider.
The dielectric loss of the liquid crystal polymer film layer prepared by the invention is less than that of a PI film and glass fiber epoxy resin, and the liquid crystal polymer film layer can be suitable for a high-frequency 5G signal transmission line with low dielectric loss.
The liquid crystal polymer in the base material layer of the flexible transmission line is anisotropic, the dielectric constant of the liquid crystal polymer can be changed by regulating and controlling the molecules of the liquid crystal polymer, and the reconfigurable flexible transmission line with different dielectric constants can be obtained under the condition that the liquid crystal polymer material in the base material layer is not changed.
Drawings
Fig. 1 is a schematic cross-sectional view of a flexible transmission line in embodiment 1.
Fig. 2 is a schematic cross-sectional view of a flexible transmission line according to embodiment 3.
Fig. 3 is a schematic structural diagram of different orientations of LCP in the flexible transmission line in example 1 and example 2.
Fig. 4 is a graph of the input return loss of the flexible transmission line in examples 1 and 2.
Fig. 5 is a graph of insertion loss of the flexible transmission line in examples 1 and 2.
Fig. 6 is a schematic structural diagram of a flexible transmission line with LCP with different orientation of the substrate layer.
Fig. 7 is a graph of characteristic impedance versus frequency for a flexible transmission line with LCP having different orientations of the substrate layer.
Fig. 8 is a schematic structural diagram of a flexible transmission line in embodiment 1, the flexible transmission line being bent at an angle α.
Fig. 9 is an input return loss graph after the flexible transmission line in embodiment 1 is bent by an angle α.
Fig. 10 is a graph of insertion loss of the flexible transmission line in example 1 after being bent by an angle α.
Reference numerals:
a signal layer 101; a first glue layer 102; a base material layer 103; a second glue layer 104; a ground layer 105.
Detailed Description
Specific embodiments of the present invention are described in further detail below with reference to the figures and examples, but the practice and protection of the present invention is not limited thereto. It is noted that the following processes, if not described in particular detail, are all realizable or understandable by those skilled in the art with reference to the prior art. The reagents or apparatus used are not indicated to the manufacturer, and are considered to be conventional products available by commercial purchase.
Example 1
The schematic cross-sectional structure of the flexible transmission line in this example is shown in fig. 1, and includes a signal layer 101, a first glue layer 102, a substrate layer 103, a second glue layer 104, and a ground layer 105, which are sequentially stacked, where the signal layer 101 is located at the uppermost layer, the ground layer 105 is located at the lowermost layer, the signal layer 101 is a copper foil, the copper foil is a sheet, and the signal layer 101, the first glue layer 102, the substrate layer 103, the second glue layer 104, and the ground layer 105 form the flexible transmission line in this example by press-fitting. The substrate layer 103 is a liquid crystal polymer film layer formed by curing a Liquid Crystal Polymer (LCP) filled in a liquid crystal cell arranged in parallel with its orientation direction, specifically, as shown in fig. 3 (a). FIG. 3 is a schematic structural view of different orientations of LCP in a flexible transmission line; FIG. 3(a) is a schematic structural diagram of an LCP film orientation parallel configuration in a flexible transmission line; the thickness of the signal layer 101 is 100 μm; the width of the signal layer 101 is 1 mm; the thickness of the ground layer 105 is 100 μm; the thicknesses of the first glue layer 102 and the second glue layer 104 are both 10 μm; the thickness of the liquid crystal polymer film layer is 300 mu m;
the LCP substrate layers 103 in this example, oriented in parallel, were prepared as follows:
and (3) manufacturing the glass substrate with the spin-coated alignment film into a planar alignment glass substrate by using a rubbing alignment method, and splicing the planar alignment glass substrate into a liquid crystal box with the thickness of 300 mu m. Pouring 4mg of 1173 photoinitiator and 200mg of RM257 liquid crystal into a 1ml brown reagent bottle, setting the temperature of a magnetic stirrer to be 100 ℃, adjusting the rotating speed, placing the brown reagent bottle into a small beaker filled with silicon oil, placing the beaker on the magnetic stirrer, stirring for 15min, pouring the mixed sample into a liquid crystal box at the temperature of 100 ℃, cooling to 95 ℃, and using 365nm ultraviolet light to induce and cure, and separating the liquid crystal box to obtain the LCP film with parallel orientation. The orientation parallel arrangement means that the orientation direction of the LCP molecules is parallel to the surface of the substrate layer 103.
The LCP substrate layer in the embodiment has the heat deformation temperature of more than 270 ℃, the continuous use temperature of more than 200 ℃, and the LCP substrate layer can not be corroded in the presence of 90% acid and 50% alkali, so that the LCP substrate layer in the embodiment has good heat stability and acid-base corrosion resistance.
Example 2:
the structure of the flexible transmission line in this example is the same as that in embodiment 1, and the difference between this example and embodiment 1 is that: the substrate layer 103 is a liquid crystal polymer film layer formed by curing Liquid Crystal Polymer (LCP) filled in a liquid crystal cell in a homeotropic configuration; the orientation direction of the LCP in this example is specifically shown in fig. 3 (b). FIG. 3(b) is a schematic diagram of the LCP film orientation in a vertical configuration in a flexible transmission line; the oriented homeotropic LCP film in this example was prepared according to the preparation method in example 1. The homeotropic configuration means that the orientation direction of the LCP molecules is perpendicular to the surface of the substrate layer 103.
Example 3:
as shown in the cross-sectional schematic of the flexible transmission line in fig. 2: the structure of the flexible transmission line in this example is different from that of embodiment 1 in that: the example is free of the first glue layer 102 and the second glue layer 104. The flexible transmission line in this example substantially agrees with the flexible transmission lines in examples 1 and 2 in performance.
Comparative example 1:
the structure of the flexible transmission line in this example is the same as that in embodiment 1, and the difference between this example and embodiment 1 is that: the base layer 103 is a film layer formed of glass fiber epoxy resin.
And (3) performance testing:
the dielectric constants of the liquid crystal polymer film layers in examples 1 and 2 and the film layer formed by the glass fiber epoxy resin in comparative example 1 were measured by a resonant cavity perturbation measurement method, and the specific test results were as follows: the dielectric constant of the liquid crystal polymer film layer of example 1, which was aligned in parallel, was 2.7, the dielectric constant of the liquid crystal polymer film layer of LCP, which was aligned in perpendicular, was 3.3 in example 2, and the dielectric constant of the glass fiber epoxy resin film layer of comparative example 1 was 5.2, the dielectric properties of the liquid crystal polymer film layers of examples 1 and 2 were more excellent than those of comparative example 1.
The transmission performance input return loss and insertion loss of the flexible transmission line in examples 1 and 2 were tested using the two ports of the network analyzer E5071, wherein fig. 4 is a graph of the input return loss (S11) of the flexible transmission line in examples 1 and 2; fig. 5 is a graph showing the insertion loss (S21) of the flexible transmission lines of example 1 and example 2. As can be seen from fig. 5: the insertion loss S21 of the flexible transmission lines of examples 1 and 2 was-0.2 dB to-0.3 dB at 5-6GHz, while the insertion loss of the flexible transmission line of comparative example 1 in which the glass fiber epoxy resin was the base material layer was-8 dB to-9 dB at 5-6GHz, and it was found that the performance of the flexible transmission lines of examples 1 and 2 was superior to that of comparative example 1.
Test samples were prepared with reference to the method of preparing the oriented LCP substrate layer 103 and the structure of the flexible transmission line in example 1, and the test samples were: sample 1: the included angle beta between the LCP molecular orientation direction and the x axis is 90 degrees; sample 2: the included angle beta between the LCP molecular orientation direction and the x axis is 45 degrees; sample 3: the included angle beta between the LCP molecular orientation direction and the x axis is 0 degree; the orientation directions of the LCP molecules in the samples 1-3 are shown in FIG. 6, wherein FIG. 6(a) is a schematic diagram of the flexible transmission line in the sample 1; fig. 6(b) is a schematic diagram of a flexible transmission line in sample 2; fig. 6(c) is a schematic diagram of a flexible transmission line in sample 3. Then, the characteristic impedance variation relation of the flexible transmission lines in the samples 1-3 along with the frequency is respectively tested, and the specific test method comprises the following steps: the radio frequency module of the COMSOL software is utilized to simulate the change relation of characteristic impedance along with frequency under the condition of different pretilt angles of liquid crystal molecules by using a finite element method. The characteristic impedance is verified by a simulation method, which is simulation data under the condition of 3 different liquid crystal molecular orientations of the liquid crystal polymer film layer, and the reconfigurability of the LCP is reflected. The specific test result is shown in FIG. 7, wherein FIG. 7(a) is a graph of the real part of the characteristic impedance of samples 1-3 as a function of frequency; FIG. 7(b) is a graph of the imaginary part of the characteristic impedance of samples 1-3 as a function of frequency. As can be seen in fig. 7: the flexible transmission line containing the liquid crystal polymer film layers with different orientation directions has good reconfigurability.
Two ends of the flexible transmission line in embodiment 1 are welded to an input signal end through tin, and are connected to a network analyzer through an SMA interface, where a bending angle of the flexible transmission line in embodiment 1 is an angle α, and the angle α is 0 °, 15 °, and 30 °, respectively, as shown in fig. 8, where fig. 8(a) is a schematic cross-sectional view of the flexible transmission line in embodiment 1 after being bent; fig. 8(b) is a schematic structural view of the flexible transmission line in embodiment 1 bent by 0 °; fig. 8(c) is a schematic structural view of the flexible transmission line in embodiment 1 bent by 15 °; fig. 8(d) is a schematic structural view of the flexible transmission line in embodiment 1 bent by 30 °; then, the input return loss and the insertion loss of the bent flexible transmission line are respectively tested, and an input return loss test chart is shown in figure 9; the insertion loss test chart is shown in fig. 10, and it can be seen from fig. 9 and 10 that: the bending degree of the flexible transmission line with the LCP substrate layer 103 does not affect the performance of the transmission line, which shows that the flexible transmission line has excellent flexibility and the transmission performance of the transmission line is not changed after bending.
In summary, the present invention mainly changes the dielectric constant of the LCP substrate layer 103 by changing the alignment orientation of the LCP liquid crystal polymer, so as to obtain the LCP substrate layer 103 with adjustable dielectric constant and lower dielectric loss, and the LCP substrate layer 103 is made into a reconfigurable 5G flexible transmission line with adjustable transmission speed. The dielectric constant of the LCP film layer in the substrate layer of the flexible transmission line is 2.7-3.3 and is far lower than that of glass fiber epoxy resin (the dielectric constant is 5.2), the dielectric property is more excellent, the insertion loss at 5-6GHz is-0.2-0.3 dB, the insertion loss of the transmission line taking the glass fiber epoxy resin as the substrate layer 103 at 5-6GHz is-8 dB-9 dB, and the transmission line performance of the flexible transmission line is more excellent.
The embodiments of the present invention have been described in detail, but the present invention is not limited to the embodiments, and various changes can be made without departing from the gist of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.
Claims (10)
1. A flexible transmission line, characterized by: the signal layer, the substrate layer and the grounding layer are sequentially stacked; the signal layer is in contact with the substrate layer; the signal layer is made of at least one of copper, gold or silver; the substrate layer comprises a liquid crystal polymer film layer; the liquid crystal polymer film layer is a liquid crystal alignment film formed by curing raw materials comprising a liquid crystal polymer and a photoinitiator.
2. The flexible transmission line of claim 1, wherein: the liquid crystal polymer comprises at least one of E7 liquid crystal, 5CB liquid crystal and RM257 liquid crystal.
3. The flexible transmission line of claim 1, wherein: the photoinitiator comprises at least one of 2-hydroxy-2-methyl-1-phenyl-1-acetone and 1-hydroxycyclohexyl phenyl ketone.
4. The flexible transmission line of claim 1, wherein: the mass ratio of the liquid crystal polymer to the photoinitiator is (40-50): 1.
5. The flexible transmission line of claim 1, wherein: the thickness of the liquid crystal polymer film layer is 200-400 μm.
6. The flexible transmission line of claim 1, wherein: the included angle between the inclination angle of the liquid crystal molecules of the liquid crystal polymer and the horizontal direction is 0-90 degrees.
7. The flexible transmission line of claim 1, wherein: the thickness of the signal layer and the thickness of the grounding layer are both 60-150 μm.
8. The flexible transmission line according to any one of claims 1 to 7, characterized in that: the flexible transmission line is a 5G flexible transmission line.
9. The flexible transmission line of claim 8, wherein: a first cementing layer is arranged between the signal layer and the substrate layer; and a second cementing layer is also arranged between the substrate layer and the grounding layer.
10. Use of the flexible transmission line according to any one of claims 1 to 9 in 5G communication materials or circuit boards.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111540441.7A CN114373580B (en) | 2021-12-16 | 2021-12-16 | Flexible transmission line and application thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111540441.7A CN114373580B (en) | 2021-12-16 | 2021-12-16 | Flexible transmission line and application thereof |
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| Publication Number | Publication Date |
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| CN114373580A true CN114373580A (en) | 2022-04-19 |
| CN114373580B CN114373580B (en) | 2024-07-26 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002164714A (en) * | 2000-11-28 | 2002-06-07 | Kyocera Corp | High frequency transmission line |
| CN106646951A (en) * | 2017-01-09 | 2017-05-10 | 南方科技大学 | Reflecting film and preparation method thereof |
| CN107300726A (en) * | 2017-07-17 | 2017-10-27 | 南方科技大学 | All-solid-state reflecting film and preparation method thereof |
| CN109777446A (en) * | 2019-03-04 | 2019-05-21 | 合肥工业大学 | A kind of liquid crystalline monomeric material of the dielectric anisotropy of terahertz wave band increase business liquid crystal |
| CN110875523A (en) * | 2018-08-30 | 2020-03-10 | 东友精细化工有限公司 | Film transmission line, antenna and image display device |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002164714A (en) * | 2000-11-28 | 2002-06-07 | Kyocera Corp | High frequency transmission line |
| CN106646951A (en) * | 2017-01-09 | 2017-05-10 | 南方科技大学 | Reflecting film and preparation method thereof |
| CN107300726A (en) * | 2017-07-17 | 2017-10-27 | 南方科技大学 | All-solid-state reflecting film and preparation method thereof |
| CN110875523A (en) * | 2018-08-30 | 2020-03-10 | 东友精细化工有限公司 | Film transmission line, antenna and image display device |
| CN109777446A (en) * | 2019-03-04 | 2019-05-21 | 合肥工业大学 | A kind of liquid crystalline monomeric material of the dielectric anisotropy of terahertz wave band increase business liquid crystal |
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| CN114373580B (en) | 2024-07-26 |
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