LCD antenna

Abstract

This application provides a liquid crystal antenna, relating to the field of antenna technology. It includes multiple antenna elements, each comprising: a first substrate; a second substrate; a liquid crystal layer located between the first and second substrates; a first electrode located between the first substrate and the liquid crystal layer; a second electrode located between the second substrate and the liquid crystal layer; a switching module electrically connected to the first electrode; a first polarizer located on the side of the first substrate away from the liquid crystal layer; and a second polarizer located on the side of the second substrate away from the liquid crystal layer. The orthographic projection shapes of the first and second electrodes on the first substrate are both annular, and the areas defined by the inner contours of the orthographic projections of the first and second electrodes on the first substrate overlap. This liquid crystal antenna possesses beam scanning capability and simultaneously has radiation and shielding functions. It has a simple structure and low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antennas, and in particular to a liquid crystal antenna. BACKGROUND

[0002] Holographic technology refers to a technology of recording an interference field formed by interference of a reference wave and a target wave by using a photosensitive material, and then obtaining the target wave by inversely deducing the target wave by using the reference wave to irradiate the interference surface. In the field of microwave applications, different sizes of metal structures are used to form surface impedance to correspond to different interference intensities, and then the reference wave is used to pass through the surface to inversely deduce the target wave.

[0003] A holographic antenna is a typical planar array antenna designed by using holographic technology. The holographic antenna can obtain a beam with a specific direction by design, and has a simple structure and low cost. However, the holographic antenna in the related art does not have a beam scanning capability.

[0004] At present, there is an urgent need to design a new liquid crystal antenna to solve the above problems. SUMMARY

[0005] Embodiments of the present application provide a liquid crystal antenna, which has a beam scanning capability and has a radiation and shielding function at the same time. The liquid crystal antenna has a simple structure and low cost.

[0006] Embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, embodiments of the present application provide a liquid crystal antenna, comprising: a plurality of antenna units arranged in an array, the antenna unit comprising:

[0008] a first substrate;

[0009] a second substrate arranged opposite to the first substrate;

[0010] a liquid crystal layer located between the first substrate and the second substrate;

[0011] a first electrode located between the first substrate and the liquid crystal layer;

[0012] a second electrode located between the second substrate and the liquid crystal layer;

[0013] a switch module electrically connected to the first electrode;

[0014] a first polarizer located on a side of the first substrate away from the liquid crystal layer;

[0015] a second polarizer located on a side of the second substrate away from the liquid crystal layer;

[0016] The first electrode and the second electrode are both annular in shape in the first substrate, and the first electrode and the second electrode overlap in the first substrate.

[0017] In some embodiments of the present application, the antenna unit further comprises a third substrate and a lens structure; the lens structure is located between the first polarizer and the third substrate.

[0018] The lens structure is at least partially overlapped with the overlapping area in the first substrate, and the third substrate is the incident side substrate of the electromagnetic wave.

[0019] In some embodiments of the present application, the focal point of the lens structure, the geometric center of the area enclosed by the inner contour of the first electrode, and the geometric center of the area enclosed by the inner contour of the second electrode are located on the same straight line.

[0020] In some embodiments of the present application, the inner contour of the first electrode and the inner contour of the second electrode overlap in the first substrate.

[0021] In some embodiments of the present application, the liquid crystal antenna further comprises a shielding layer and a plurality of connection traces, and the shielding layer and the connection traces are arranged in the same layer.

[0022] The first electrode is electrically connected to the switch module through the connection traces.

[0023] The connection traces are overlapped with the first area of the first substrate in the first substrate, the outer contour of the first electrode encloses the second area of the first substrate in the first substrate, the shielding layer is not overlapped with the first area in the first substrate, and the shielding layer is not overlapped with the second area in the first substrate.

[0024] In some embodiments of the present application, the shielding layer is overlapped with at least part of the area of the first substrate other than the first area and the second area in the first substrate.

[0025] In some embodiments of the present application, the shielding layer and the first electrode are arranged in the same layer.

[0026] In some embodiments of the present application, the second electrodes of the antenna units are electrically connected together.

[0027] In some embodiments of the present application, the liquid crystal antenna further comprises a plurality of cavity structures, and the third substrate, the first polarizer and the area between every two adjacent lens structures constitute the cavity structures.

[0028] In some embodiments of the present application, the switch module comprises an FPGA sub-module or a transistor control circuit.

[0029] In some embodiments of the present application, when the switch module comprises an FPGA sub-module, each FPGA sub-module to which a plurality of antenna units are electrically connected constitutes an FPGA circuit; and the liquid crystal antenna further comprises a driving chip, and the FPGA circuit is integrated on the driving chip.

[0030] In some embodiments of the present application, when the switch module comprises a transistor control circuit, the antenna unit further comprises a thin film transistor, and a first electrode of the thin film transistor is electrically connected to the first electrode.

[0031] The thin film transistor is located between the first substrate and the liquid crystal layer, and the orthographic projection of the thin film transistor on the first substrate and the orthographic projection of the second electrode on the first substrate do not overlap each other.

[0032] In some embodiments of the present application, the thin film transistor comprises:

[0033] a gate electrode located on the first substrate;

[0034] a gate insulating layer covering at least the gate electrode;

[0035] an active layer located on the side of the gate insulating layer away from the first substrate;

[0036] the first electrode and the second electrode, the first electrode and the second electrode being in direct contact with two ends of the active layer respectively, and exposing a middle region of the active layer;

[0037] a passivation layer covering at least the first electrode, the second electrode and the middle region of the active layer.

[0038] In some embodiments of the present application, the middle region of the active layer comprises a semiconductor region and a conductor region located on both sides of the semiconductor region.

[0039] The orthographic projection of the semiconductor region on the first substrate and the orthographic projection of the gate electrode on the first substrate overlap; and the orthographic projection of the conductor region on the first substrate is located in a region outside the outer contour of the orthographic projection of the gate electrode on the first substrate.

[0040] The embodiment of the present application provides a liquid crystal antenna, comprising: a plurality of antenna units arranged in an array, the antenna unit comprising: a first substrate; a second substrate arranged opposite to the first substrate; a liquid crystal layer located between the first substrate and the second substrate; a first electrode located between the first substrate and the liquid crystal layer; a second electrode located between the second substrate and the liquid crystal layer; a switch module electrically connected with the first electrode; a first polarizer located on a side of the first substrate away from the liquid crystal layer; a second polarizer located on a side of the second substrate away from the liquid crystal layer; wherein the first electrode is annular in shape in orthographic projection on the first substrate, and the second electrode is annular in shape in orthographic projection on the first substrate, and an area circumscribed by an inner contour of the orthographic projection of the first electrode on the first substrate and an area circumscribed by an inner contour of the orthographic projection of the second electrode on the first substrate overlap.

[0041] In the embodiment of the present application, liquid crystal material is used, the dielectric constant of the liquid crystal layer is changed by applying a voltage between the annular first electrode and the second electrode, so that the radiation characteristics of each antenna unit in the liquid crystal antenna are adjusted, and scanning in two dimensions of azimuth angle and elevation angle can be realized; in addition, the combined adjustment of the first polarizer, the second polarizer, the first electrode and the second electrode on the liquid crystal layer can realize the radiation and shielding functions of the liquid crystal antenna at the same time; and the liquid crystal antenna also has the advantages of simple structure and low preparation cost.

[0042] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, the content of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed in the embodiment or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0044] Figure 1 And Figure 4 Structure schematic diagrams of two liquid crystal antennas provided by the embodiments of the present application;

[0045] Figure 2 Structure schematic diagram of a second electrode provided by the embodiments of the present application;

[0046] Figure 3 And Figure 5Two structural diagrams of the first electrode provided for the embodiments of the present application. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0048] In the drawings, the thicknesses of regions and layers can be exaggerated for clarity. Like reference numerals in the drawings denote like or similar elements, and thus their detailed descriptions will be omitted. In addition, the drawings are merely schematic illustrations of the present application and are not necessarily drawn to scale.

[0049] Unless otherwise required by context, the term "comprises" in the specification and claims is to be construed as an open, inclusive meaning, i.e., "comprises, but is not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" are intended to mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present application. The illustrative representations of the above terms do not necessarily indicate a reference to the same embodiment or example. In addition, the specific features, structures, materials, or characteristics described can be included in any suitable way in any one or more embodiments or examples.

[0050] In the embodiments of the present application, the same items or similar items with substantially the same functions and effects are partially referred to as "first", "second", etc. only for the purpose of clearly describing the technical solutions of the embodiments of the present application, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features.

[0051] The embodiments of the present application provide a liquid crystal antenna, comprising: a plurality of antenna units arranged in an array, wherein each antenna unit comprises: Figure 1 and Figure 4 As shown in the figure, the antenna unit comprises:

[0052] a first substrate 1;

[0053] a second substrate 2 arranged opposite to the first substrate 1;

[0054] a liquid crystal layer 4 located between the first substrate 1 and the second substrate 2;

[0055] a first electrode 5 located between the first substrate 1 and the liquid crystal layer 4;

[0056] a second electrode 6 between the second substrate 2 and the liquid crystal layer 4;

[0057] a switch module electrically connected with the first electrode 5;

[0058] a first polarizer 7 on a side of the first substrate 1 away from the liquid crystal layer 4;

[0059] a second polarizer 8 on a side of the second substrate 2 away from the liquid crystal layer 4;

[0060] wherein the first electrode 5 and the second electrode 6 are both in the shape of a ring when projected onto the first substrate 1, and the area enclosed by the inner contour of the projection of the first electrode 5 onto the first substrate 1 overlaps with the area enclosed by the inner contour of the projection of the second electrode 6 onto the first substrate 1.

[0061] Here, the materials of the first substrate 1 and the second substrate 2 are not limited. For example, the first substrate 1 and the second substrate 2 are both glass substrates.

[0062] Here, the liquid crystal material in the liquid crystal layer 4 is not limited. For example, the liquid crystal material in the liquid crystal layer 4 can be similar to the liquid crystal material in a liquid crystal display.

[0063] In an exemplary embodiment, the material of the first electrode 5 can be a metal material. For example, at least one of copper (Cu), aluminum (Al) and molybdenum (Mo).

[0064] In an exemplary embodiment, the material of the second electrode 6 can be a metal oxide, for example, indium tin oxide (ITO).

[0065] Here, the specific structure of the switch module is not limited. For example, the switch module can include a plurality of thin film transistors, each thin film transistor controlling one antenna unit; or the switch module includes a plurality of FPGA (Field-Programmable Gate Array) sub-modules, each FPGA sub-module controlling one antenna unit, and the FPGA sub-modules constitute an FPGA circuit.

[0066] Here, the specific position of the switch module is not limited. For example, for a control circuit composed of a plurality of thin film transistors, it can be arranged between the liquid crystal layer 4 and the first substrate 1; for an FPGA circuit, it can be arranged on an external circuit board electrically connected with the liquid crystal antenna.

[0067] In an exemplary embodiment, the polarization directions of the first polarizer 7 and the second polarizer 8 are perpendicular.

[0068] The first electrode 5 and the second electrode 6 are both annular in shape.

[0069] For example, the annular shape can be a polygonal ring, such as a square ring as shown in FIGS. 1B and 1C, or an arcuate ring, such as a circular ring or an elliptical ring. Figure 2 Figure 3 For example, the annular shape can be a polygonal ring, such as a square ring as shown in FIGS. 1B and 1C, or an arcuate ring, such as a circular ring or an elliptical ring.

[0070] The first electrode 5 and the second electrode 6 are both annular in shape.

[0071] The antenna provided by the embodiments of the present application uses liquid crystal material, and the dielectric constant of the liquid crystal layer is changed by applying a voltage between the annular first electrode and the second electrode, so as to adjust the radiation characteristics of each antenna unit in the liquid crystal antenna, and the scanning in two dimensions of the azimuth angle and the elevation angle can be realized. In addition, the combined adjustment of the liquid crystal layer by the first polarizer, the second polarizer, the first electrode and the second electrode can realize the radiation and shielding functions of the liquid crystal antenna at the same time. Moreover, the liquid crystal antenna has the advantages of simple structure and low manufacturing cost.

[0072] In actual application, when the electromagnetic wave enters the liquid crystal antenna from the first polarizer 7, the first polarizer 7 produces polarization effect on the electromagnetic wave, and the part of the electromagnetic wave with the same polarization direction (also called the polarization direction of the electromagnetic wave) as the first polarizer 7 is transmitted. This part of the electromagnetic wave passes through the middle of the annular first electrode 5 and enters the liquid crystal layer 4. The liquid crystal layer 4 can further change the propagation direction of the electromagnetic wave, and the electromagnetic wave emitted from the liquid crystal layer 4 passes through the annular second electrode 6 and then is emitted from the liquid crystal antenna, so as to change the direction of the electromagnetic wave initially emitted into the liquid crystal antenna. Through the different effects of the multiple liquid crystal units in the liquid crystal antenna, the radiation characteristics of each antenna unit in the liquid crystal antenna can be adjusted, so as to realize the scanning in two dimensions of the azimuth angle and the elevation angle. In addition, by controlling the voltage between the first electrode 5 and the second electrode 6, the electromagnetic wave transmittance of the liquid crystal layer 4 is reduced, and the electromagnetic wave entering the liquid crystal antenna cannot be emitted from the annular electrode, so as to realize the shielding effect on the electromagnetic wave.

[0073] It should be noted that the electromagnetic wave mentioned in the embodiments of the present application can be a microwave.

[0074] ​In some embodiments of the present application, the antenna unit further comprises a third substrate 3 and a lens structure 9; the lens structure 9 is located between the first polarizer 7 and the third substrate 3; wherein the orthographic projection of the lens structure 9 on the first substrate 1 at least overlaps the above-mentioned overlapping area, and the third substrate 3 is the incident side substrate of the electromagnetic wave.

[0075] In exemplary embodiments, the lens structure 9 can play a role in converging electromagnetic waves, thereby increasing the collection capability of electromagnetic waves.

[0076] The meaning that the orthographic projection of the lens structure 9 on the first substrate 1 at least overlaps the above-mentioned overlapping area is that: the orthographic projection of the lens structure 9 on the first substrate 1 only overlaps the overlapping area; or, the orthographic projection of the lens structure 9 on the first substrate 1 not only overlaps the overlapping area, but also overlaps the orthographic projection of the first electrode 5 outside the overlapping area; or, the orthographic projection of the lens structure 9 on the first substrate 1 not only overlaps the overlapping area, but also overlaps the orthographic projection of the second electrode 6 outside the overlapping area; or, the orthographic projection of the lens structure 9 on the first substrate 1 not only overlaps the overlapping area, but also overlaps the orthographic projection of the first electrode 5 outside the overlapping area, and also overlaps the orthographic projection of the second electrode 6 outside the overlapping area.

[0077] Wherein, the above-mentioned overlapping area refers to the overlapping area existing between the area circumscribed by the inner contour of the orthographic projection of the first electrode 5 on the first substrate 1 and the area circumscribed by the inner contour of the orthographic projection of the second electrode 6 on the first substrate 1.

[0078] In some embodiments of the present application, the focal point of the lens structure 9, the geometric center of the area circumscribed by the inner contour of the first electrode 5, and the geometric center of the area circumscribed by the inner contour of the second electrode 6 are located on the same straight line.

[0079] In actual application, since the electromagnetic waves converging near the focal point of the lens structure 9 are the strongest, by setting the geometric center of the area circumscribed by the inner contour of the first electrode 5, the geometric center of the area circumscribed by the inner contour of the second electrode 6, and the focal point of the lens structure 9 on the same straight line, the collected electromagnetic waves can be largely propagated from the inner contours of the first electrode 5 and the second electrode 6, thereby improving the radiation intensity of the antenna.

[0080] In exemplary embodiments, the lens structure needs to satisfy the following size conditions:

[0081] Formula (1)

[0082] Formula (2)

[0083] Substituting formula (2) into formula (1), we can get:

[0084] Formula (3)

[0085] wherein k is the wave vector size, d is the thickness of the lens structure in the direction perpendicular to the first substrate, l is the length of the lateral axis of the lens structure, f is the focal length of the lens structure, and λ is the wavelength of the electromagnetic wave.

[0086] In some embodiments of the present application, the inner contour of the orthographic projection of the first electrode 5 on the first substrate 1 and the inner contour of the orthographic projection of the second electrode 6 on the first substrate 1 overlap.

[0087] In the present application, by setting the inner contour of the orthographic projection of the first electrode 5 on the first substrate 1 and the inner contour of the orthographic projection of the second electrode 6 on the first substrate 1 to overlap, the electromagnetic wave passing through the first electrode 5 can pass through the second electrode 6 without considering the liquid crystal layer 4, thereby reducing the loss of the electromagnetic wave inside the liquid crystal antenna and improving the radiation intensity.

[0088] In some embodiments of the present application, referring to Figure 3 or Figure 5 As shown, the liquid crystal antenna further comprises a shielding layer 51 and a plurality of connection wires 52, and the shielding layer 51 and the connection wires 52 are arranged in the same layer.

[0089] In an exemplary embodiment, the shielding layer 51 and the first electrode 5 are arranged in the same layer.

[0090] The meaning of the above-mentioned arrangement in the same layer is that they are made in one patterning process and are located in the same layer.

[0091] The one patterning process refers to being made by an exposure, development and etching process under the same mask.

[0092] Wherein the first electrode 5 is electrically connected with a switch module (not drawn) through the connection wire 52;

[0093] In an exemplary embodiment, when the switch module is arranged on an externally connected chip, the structure of the first electrode 5, the shielding layer 51 and the connection wire 52 can be as shown in Figure 4 or Figure 5 Each first electrode 5 is electrically connected with the externally connected switch module through one connection wire 52. Of course, the first electrode 5 and the connection wire 52 can also be arranged in other ways, which are not limited here.

[0094] In an exemplary embodiment, when the switch module comprises a plurality of transistors TFT as shown in Figure 1 and are all arranged in the liquid crystal antenna, the orthographic projection of the transistor TFT on the first substrate 1 and the orthographic projection of the first electrode 5 on the first substrate 1 do not overlap, and it should be noted that Figure 3The structure of the transistor is not embodied in the shown structure. At this time, the orthogonal projection of the shielding layer 51 on the first substrate 1 and the orthogonal projection of the transistor TFT on the substrate do not overlap each other.

[0095] In an exemplary embodiment, the orthogonal projection of the connecting wire 52 on the first substrate 1 covers the first region of the first substrate 1, the outer contour of the orthogonal projection of the first electrode 5 on the first substrate 1 circumscribes the second region of the first substrate 1, the orthogonal projection of the shielding layer 51 on the first substrate 1 does not overlap the first region, and the orthogonal projection of the shielding layer 51 on the first substrate 1 does not overlap the second region.

[0096] In some embodiments of the present application, the orthogonal projection of the shielding layer 51 on the first substrate 1 covers at least part of the region of the first substrate 1 other than the first region and the second region.

[0097] The meaning that the orthogonal projection of the shielding layer 51 on the first substrate 1 covers at least part of the region of the first substrate 1 other than the first region and the second region is that the orthogonal projection of the shielding layer 51 on the first substrate 1 covers part of the region of the first substrate 1 other than the first region and the second region, or the orthogonal projection of the shielding layer 51 on the first substrate 1 covers all the regions of the first substrate 1 other than the first region and the second region, which are not provided with the conductive film layer.

[0098] In some embodiments of the present application, the shielding layer 51 and the first electrode 5 are provided in the same layer.

[0099] In some embodiments of the present application, referring to Figure 2 As shown, the second electrodes 6 of each antenna unit are electrically connected together. It should be noted that in Figure 2 , only the second electrodes 6 of the same row are electrically connected together through the wire 61, and in actual application, a plurality of wires 61 are also electrically connected together.

[0100] In some embodiments of the present application, referring to Figure 1 As shown, the liquid crystal antenna further comprises a plurality of cavity structures, and the regions between the third substrate 3, the first polarizer 7 and each adjacent two lens structures 9 constitute the cavity structures.

[0101] In an exemplary embodiment, the liquid crystal antenna can further comprise the first alignment film 15 and the second alignment film 16 located on both sides of the liquid crystal layer 4 as shown in Figure 1 The alignment film can play an alignment role, so that the liquid crystal molecules in the liquid crystal layer 4 have a certain pre-tilt angle.

[0102] Here, the specific angle of the pre-tilt angle is not limited; for example, the pre-tilt angle can be 15°.

[0103] The liquid crystal antenna also includes a frame adhesive, which surrounds the liquid crystal layer 4 and fixes the first substrate 1 and the second substrate 2 together. The specific structure and placement of the frame adhesive can be found in related technologies regarding the placement of frame adhesives in liquid crystal display panels, and will not be elaborated upon here.

[0104] In some embodiments of this application, the switching module includes an FPGA submodule or a transistor control circuit.

[0105] In some embodiments of this application, reference is made to Figure 4 As shown, when the switching module includes an FPGA submodule, the FPGA submodules electrically connected to the multiple antenna units constitute the FPGA circuit; the liquid crystal antenna also includes a driver chip, and the FPGA circuit is integrated into the driver chip ( Figure 4 (Not shown in the diagram). Each first electrode 5 is electrically connected to its corresponding FPGA submodule via a connecting trace 52 to control the opening or closing of each antenna unit.

[0106] In some embodiments of this application, reference is made to Figure 1 As shown, when the switching module includes a transistor control circuit, the antenna unit also includes a thin-film transistor (TFT), and the first electrode and the first electrode of the thin-film transistor are electrically connected; wherein, the thin-film transistor is located between the first substrate 1 and the liquid crystal layer 4, and the orthographic projection of the thin-film transistor TFT on the first substrate 1 and the orthographic projection of the second electrode 6 on the first substrate 1 do not overlap.

[0107] In some embodiments of this application, the thin-film transistor includes: a gate 10 located on a first substrate 1; a gate insulating layer 11 covering at least the gate 10; an active layer 12 located on the side of the gate insulating layer 11 away from the first substrate 1; a first electrode 13 and a second electrode 17, the first electrode 13 and the second electrode 17 respectively covering both ends of the active layer 12 and directly contacting both ends of the active layer 12, the first electrode 13 and the second electrode 17 exposing the middle region of the active layer 12; and a passivation layer 14 covering at least the first electrode 13, the second electrode 17 and the middle region of the active layer 12.

[0108] In an exemplary embodiment, the material of the gate 10 includes metals, such as molybdenum (Mo), aluminum (Al), or copper (Cu).

[0109] The gate insulating layer 11 is made of an inorganic material, such as at least one or a combination of silicon oxide, silicon nitride, and silicon oxynitride.

[0110] In an exemplary embodiment, the first electrode 13 can be the source and the second electrode 17 can be the drain; or, the first electrode 13 can be the drain and the second electrode 17 can be the source. The specific choice can be determined according to the actual situation, and is not limited here.

[0111] In the exemplary embodiment, the material of the active layer 12 can be a semiconductor carbon nanotube film. In practical applications, a carbon nanotube solution with a concentration of 50ug / ml can be configured first, and then diluted and dispersed using toluene or xylene to make the concentration of the semiconductor carbon nanotube less than 80%. After solution film formation, the active layer film is obtained, and then the ICP (Inductively Coupled Plasma) technology is used for etching to obtain the active layer 12.

[0112] In some embodiments of the present application, the middle region of the active layer 12 includes a semiconductor region and a conductor region located on both sides of the semiconductor region; the orthographic projection of the semiconductor region on the first substrate 1 and the orthographic projection of the gate 10 on the first substrate 1 overlap; the orthographic projection of the conductor region on the first substrate 1 is located in a region outside the outer contour of the orthographic projection of the gate 10 on the first substrate 1.

[0113] In the embodiments of the present application, by providing a conductor region in the middle region of the active layer 12 exposed by the first electrode 13 and the second electrode 17, the active layer 12 located in the conductor region can play a role of assisting the thin film transistor in voltage division, thereby improving the high voltage resistance of the thin film transistor, so that the thin film transistor can be applied to a high voltage circuit.

[0114] In the exemplary embodiment, the material of the first electrode and the second electrode can include at least one or a combination of multiple of copper (Cu), titanium (Ti) or palladium (Pd).

[0115] For example, the first electrode and the second electrode can both be a titanium / palladium (Ti / Pd) stack, and the thickness thereof can be 5nm / 1.5μm.

[0116] Here, the specific material of the passivation layer 14 is not limited, and for example, the passivation layer 14 can be a yttrium oxide / aluminum oxide stack, and the thickness of the yttrium oxide / aluminum oxide stack can be 5nm / 50nm.

[0117] The working process of the liquid crystal antenna will be introduced below in combination with the structure of the liquid crystal antenna shown in Figure 1 and Figure 4 The working process of the liquid crystal antenna will be introduced below in combination with the structure of the liquid crystal antenna shown in

[0118] For a one-dimensional antenna, the reference wave equation is:

[0119] Equation (4)

[0120] The target wave equation is:

[0121] Equation (5)

[0122] The interference wave equation is:

[0123] Equation (6)

[0124] wherein k m represents the propagation constant of the reference wave, k0 is the free space wave number, θ0 is the angle between the target wave and the normal of the antenna plane, x n is the x coordinate at the nth unit.

[0125] Since the liquid crystal antenna provided by the embodiments of the present application is a two-dimensional antenna, the y direction coordinate is added, and x and y are converted into polar coordinates;

[0126] Equation (7)

[0127] Equation (8)

[0128] wherein the azimuth angle , and r is the radial distance, then the interference wave equation is:

[0129] Equation (9)

[0130] Equation (10)

[0131] is the target wave pointing azimuth angle, is the initial wave azimuth angle, and and are substituted into , and the following can be obtained:

[0132] Equation (11)

[0133] wherein is the reference wave amplitude, is the target wave amplitude.

[0134] In actual application, the value is further subjected to binary discretization processing, and the state of the switch module of each antenna unit can be determined by the required target wave number. If the polarization state of the incident wave after passing through the first polarizer is perpendicular to the polarization state of the second polarizer, the corresponding antenna unit state is off, at this time, the energy coupled out of the second polarizer is minimum, and the liquid crystal antenna is in the state of shielding electromagnetic waves. If the polarization state of the incident wave after passing through the first polarizer is the same as the polarization state of the second polarizer, it represents that the corresponding antenna unit state is on, at this time, the energy coupled out of the second polarizer is maximum, the size of the antenna unit radiation energy is adjusted by adjusting the bias voltage of the liquid crystal (the voltage between the first electrode and the second electrode), and in addition, the bias voltage in each antenna unit is controlled by the switch module in the liquid crystal antenna to realize beam scanning.

[0135] In addition, the liquid crystal antenna of the embodiment of the present application can realize the radiation and shielding of microwaves (electromagnetic waves) by the combination of the upper and lower polarizers (the first polarizer and the second polarizer) and the modulation of the liquid crystal by the voltage, and has the advantages of simple structure, easy compatibility with the existing panel technology, and low cost.

[0136] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A liquid crystal antenna, characterized by, The liquid crystal antenna comprises: a plurality of antenna units arranged in an array, the antenna units comprising: a first substrate; a second substrate arranged opposite to the first substrate; a liquid crystal layer between the first substrate and the second substrate; a first electrode between the first substrate and the liquid crystal layer; a second electrode between the second substrate and the liquid crystal layer; a switch module electrically connected to the first electrode; a first polarizer on a side of the first substrate away from the liquid crystal layer; a second polarizer on a side of the second substrate away from the liquid crystal layer; wherein the first electrode has a ring-shaped orthographic projection on the first substrate, and the second electrode has a ring-shaped orthographic projection on the first substrate, and the first electrode orthographic projection on the first substrate and the second electrode orthographic projection on the first substrate have an overlapping area; the polarization directions of the first polarizer and the second polarizer are perpendicular; the inner contour of the first electrode orthographic projection on the first substrate and the inner contour of the second electrode orthographic projection on the first substrate overlap.

2. The liquid crystal antenna according to claim 1, wherein The antenna unit further comprises a third substrate and a lens structure; the lens structure is between the first polarizer and the third substrate; wherein the lens structure orthographic projection on the first substrate at least overlaps with the overlapping area, and the third substrate is the incident side substrate of electromagnetic waves.

3. The liquid crystal antenna of claim 2, wherein, The focal point of the lens structure, the geometric center of the area circumscribed by the inner contour of the first electrode, and the geometric center of the area circumscribed by the inner contour of the second electrode are located on the same straight line.

4. The liquid crystal antenna of claim 1, wherein, The liquid crystal antenna further comprises a shielding layer and a plurality of connection traces, and the shielding layer and the connection traces are arranged in the same layer; the first electrode is electrically connected to the switch module through the connection traces; the connection traces orthographic projection on the first substrate covers a first area of the first substrate, the outer contour of the first electrode orthographic projection on the first substrate circumscribes a second area of the first substrate, the shielding layer orthographic projection on the first substrate does not overlap with the first area, and the shielding layer orthographic projection on the first substrate does not overlap with the second area.

5. The liquid crystal antenna of claim 4, wherein, The shielding layer orthographic projection on the first substrate covers at least part of the area of the first substrate other than the first area and the second area.

6. The liquid crystal antenna of claim 4, wherein, The shielding layer and the first electrode are arranged in the same layer.

7. The liquid crystal antenna of claim 1, wherein, The second electrodes of the antenna units are electrically connected together.

8. The liquid crystal antenna of claim 2, wherein, The liquid crystal antenna further comprises a plurality of cavity structures, and the area between the third substrate, the first polarizer, and every two adjacent lens structures constitutes a cavity structure.

9. The liquid crystal antenna according to any one of claims 1 to 8, wherein, The switch module comprises an FPGA submodule or a transistor control circuit.

10. The liquid crystal antenna of claim 9, wherein, In the case where the switch module comprises an FPGA submodule, the FPGA submodules of the plurality of antenna units electrically connected together constitute an FPGA circuit; the liquid crystal antenna further comprises a driving chip, and the FPGA circuit is integrated on the driving chip.

11. The liquid crystal antenna of claim 9, wherein, In the case that the switch module comprises a transistor control circuit, the antenna unit further comprises a thin film transistor, a first electrode of the thin film transistor is electrically connected with the first electrode; The thin film transistor is located between the first substrate and the liquid crystal layer, and a normal projection of the thin film transistor on the first substrate does not overlap with a normal projection of the second electrode on the first substrate.

12. The liquid crystal antenna of claim 11, wherein, The thin film transistor comprises: a gate electrode located on the first substrate; a gate insulating layer covering at least the gate electrode; an active layer located on a side of the gate insulating layer away from the first substrate; the first electrode and the second electrode, the first electrode and the second electrode are in direct contact with two ends of the active layer respectively, and an intermediate region of the active layer is exposed; a passivation layer covering at least the first electrode, the second electrode and the intermediate region of the active layer.

13. The liquid crystal antenna of claim 12, wherein, The intermediate region of the active layer comprises a semiconductor region and conductor regions located on two sides of the semiconductor region; A normal projection of the semiconductor region on the first substrate overlaps with a normal projection of the gate electrode on the first substrate; A normal projection of the conductor region on the first substrate is located in a region outside an outer contour of the normal projection of the gate electrode on the first substrate.

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