阅读说明：本技术 液晶移相器及天线 (Liquid crystal phase shifter and antenna ) 是由 武杰 丁天伦 王瑛 李亮 贾皓程 唐粹伟 ***强 于 2019-10-17 设计创作，主要内容包括：本发明提供一种液晶移相器及天线,属于通信技术领域。本发明的液晶移相器,包括：相对设置的第一基底和第二基底,位于所述第一基底和所述第二基底之间的液晶层、第一电极、第二电极,设置在第一基底背离液晶层一侧的第一屏蔽电极,及设置在第二基底背离液晶层一侧的第二屏蔽电极；其中,所述第一电极和所述第二电极在被施加电压而产生电场时,改变液晶层的介电常数,以调整微波信号的移相度；所述第一屏蔽电极和所述第二屏蔽电极,用于对所述第一电极和所述第二电极在被施加电压时产生的辐射进行屏蔽。(The invention provides a liquid crystal phase shifter and an antenna, and belongs to the technical field of communication. The liquid crystal phase shifter of the present invention comprises: the liquid crystal display panel comprises a first substrate, a second substrate, a liquid crystal layer, a first electrode, a second electrode, a first shielding electrode and a second shielding electrode, wherein the first substrate and the second substrate are oppositely arranged, the liquid crystal layer, the first electrode and the second electrode are positioned between the first substrate and the second substrate, the first shielding electrode is arranged on one side, away from the liquid crystal layer, of the first substrate, and the second shielding electrode is arranged on one side, away from the liquid crystal layer, of; when the first electrode and the second electrode are applied with voltage to generate an electric field, the dielectric constant of the liquid crystal layer is changed to adjust the phase shift degree of the microwave signal; the first shielding electrode and the second shielding electrode are used for shielding radiation generated by the first electrode and the second electrode when voltage is applied.)

1. A liquid crystal phase shifter, comprising: the liquid crystal display panel comprises a first substrate, a second substrate, a liquid crystal layer, a first electrode, a second electrode, a first shielding electrode and a second shielding electrode, wherein the first substrate and the second substrate are oppositely arranged, the liquid crystal layer, the first electrode and the second electrode are positioned between the first substrate and the second substrate, the first shielding electrode is arranged on one side, away from the liquid crystal layer, of the first substrate, and the second shielding electrode is arranged on one side, away from the liquid crystal layer, of; wherein the content of the first and second substances,

when the first electrode and the second electrode are applied with voltage to generate an electric field, the dielectric constant of the liquid crystal layer is changed to adjust the phase shift degree of the microwave signal;

the first shielding electrode and the second shielding electrode are used for shielding radiation generated by the first electrode and the second electrode when voltage is applied.

2. The liquid crystal phase shifter of claim 1, wherein the first electrode and the second electrode each comprise a strip transmission line.

3. The liquid crystal phase shifter of claim 2, wherein the first electrode is disposed on a first substrate, the second electrode is disposed on a second substrate, and orthographic projections of the first electrode and the second electrode on the first substrate at least partially overlap.

4. The liquid crystal phase shifter of claim 2, wherein the first electrode is disposed on a first substrate, the second electrode is disposed on a second substrate, and orthographic projections of the first electrode and the second electrode on the first substrate are non-overlapping.

5. The liquid crystal phase shifter of claim 2, wherein the first electrode and the second electrode are disposed on the first substrate or the second substrate at a distance.

6. The liquid crystal phase shifter according to claim 4 or 5, wherein a pitch of the first electrode and the second electrode in a horizontal direction is less than 2 times a width of the first electrode.

7. The liquid crystal phase shifter according to claim 1, wherein the first substrate and the liquid crystal layer satisfy the following condition:

wherein epsilon₁Is the dielectric constant of the first substrate; epsilon_LCIs the dielectric constant of the liquid crystal layer;

H_glassis the thickness of the first substrate; h_LCIs the thickness of the liquid crystal layer.

8. The liquid crystal phase shifter of claim 1, wherein a spacer is further disposed between the first substrate and the second substrate to maintain a cell thickness of the liquid crystal layer.

9. The liquid crystal phase shifter of claim 8, wherein the spacers are uniformly distributed between the first substrate and the second substrate.

10. The liquid crystal phase shifter of claim 1, wherein the first shield electrode and the second shield electrode each comprise a ground electrode.

11. The liquid crystal phase shifter of claim 1, wherein the material of the first shielding electrode, the second shielding electrode, the first electrode, and the second electrode comprises a metal.

12. The liquid crystal phase shifter of claim 1, wherein the liquid crystal layer has a thickness of 5-10 μm.

13. An antenna comprising the liquid crystal phase shifter of any one of claims 1-12.

Technical Field

The invention belongs to the technical field of communication, and particularly relates to a liquid crystal phase shifter and an antenna.

Background

The phase shifter is a device capable of adjusting the phase of microwaves, is widely applied to electronic communication systems, and is a core component in phased array radars, synthetic aperture radars, radar electronic countermeasure, satellite communication and transceiver. High performance phase shifters therefore play a crucial role in these systems.

The inventor researches and discovers that the existing phase shifter has the defects of high loss, long response time, large volume and the like, and cannot meet the requirement of the development of an electronic communication system in a new and advanced way.

Disclosure of Invention

The present invention is directed to at least one of the technical problems of the prior art, and provides a liquid crystal phase shifter and an antenna.

In a first aspect, an embodiment of the present invention provides a liquid crystal phase shifter, including: the liquid crystal display panel comprises a first substrate, a second substrate, a liquid crystal layer, a first electrode, a second electrode, a first shielding electrode and a second shielding electrode, wherein the first substrate and the second substrate are oppositely arranged, the liquid crystal layer, the first electrode and the second electrode are positioned between the first substrate and the second substrate, the first shielding electrode is arranged on one side, away from the liquid crystal layer, of the first substrate, and the second shielding electrode is arranged on one side, away from the liquid crystal layer, of; wherein the content of the first and second substances,

when the first electrode and the second electrode are applied with voltage to generate an electric field, the dielectric constant of the liquid crystal layer is changed to adjust the phase shift degree of the microwave signal;

the first shielding electrode and the second shielding electrode are used for shielding radiation generated by the first electrode and the second electrode when voltage is applied.

Optionally, the first electrode and the second electrode each comprise a strip transmission line.

Optionally, the first electrode is disposed on a first substrate, the second electrode is disposed on a second substrate, and orthographic projections of the first electrode and the second electrode on the first substrate at least partially overlap.

Optionally, the first electrode is disposed on a first substrate, the second electrode is disposed on a second substrate, and orthographic projections of the first electrode and the second electrode on the first substrate are non-overlapping.

Optionally, the first electrode and the second electrode are both disposed on the first substrate or the second substrate, and are disposed at an interval.

Optionally, the first electrode and the second electrode are spaced apart in the horizontal direction by less than 2 times the width of the first electrode.

Optionally, the first substrate and the liquid crystal layer satisfy the following condition:

wherein epsilon₁Is the dielectric constant of the first substrate; epsilon_LCIs the dielectric constant of the liquid crystal layer;

H_glassis the thickness of the first substrate; h_LCIs the thickness of the liquid crystal layer.

Optionally, a spacer is further disposed between the first substrate and the second substrate to maintain a cell thickness of the liquid crystal layer.

Optionally, the spacers are evenly distributed between the first substrate and the second substrate.

Optionally, the first shield electrode and the second shield electrode each comprise a ground electrode.

Optionally, the material of the first shielding electrode, the second shielding electrode, the first electrode and the second electrode comprises a metal.

Optionally, the thickness of the liquid crystal layer is 5-10 μm.

In a second aspect, an embodiment of the present invention provides an antenna, which includes the above-mentioned liquid crystal phase shifter.

Drawings

FIG. 1 is a top view of a liquid crystal phase shifter according to an embodiment of the present invention;

FIG. 2 is a top view of a first substrate of the liquid crystal phase shifter of FIG. 1, adjacent to a liquid crystal layer;

FIG. 3 is a cross-sectional view A-A' of FIG. 1;

FIG. 4 is a cross-sectional view of B-B' of FIG. 1;

FIG. 5 is a top view of spacers on a first passivation layer of the liquid crystal phase shifter of FIG. 1;

FIG. 6 is an equivalent circuit diagram of the liquid crystal phase shifter of FIG. 1;

FIG. 7 is a cross-sectional view of a liquid crystal phase shifter;

FIG. 8 is a cross-sectional view of another liquid crystal phase shifter;

fig. 9 is a cross-sectional view of still another liquid crystal phase shifter.

Wherein the reference numerals are: 10. a first substrate; 11. a first electrode; 12. a first shield electrode; 20. a second substrate; 21. a second electrode; 22 a second shielding electrode; 30. a liquid crystal layer; 41. a first passivation layer; 42. a second passivation layer; 50. a spacer.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. Also, the use of the terms "a," "an," or "the" and similar referents do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

The vast majority of phase shifters currently on the market are ferrite phase shifters and PIN diode phase shifters. The ferrite phase shifter has the defects of large volume and low response speed, and is not suitable for high-speed beam scanning; the diode phase shifter has large power consumption and is not favorable for being used as a portable low-power phased array system.

Specifically, in the embodiment of the present invention, the liquid crystal phase shifter is mainly taken as an example of a strip line liquid crystal phase shifter, that is, the liquid crystal phase shifter includes: the liquid crystal display panel comprises a first substrate, a second substrate, a first electrode, a second electrode and a liquid crystal layer, wherein the first substrate and the second substrate are oppositely arranged, and the first electrode, the second electrode and the liquid crystal layer are positioned between the first substrate and the second substrate; the first electrode and the second electrode are strip transmission lines, when different voltages are applied to the first electrode and the second electrode, an electric field is formed between the first electrode and the second electrode, the deflection angle of liquid crystal molecules of the liquid crystal layer is changed, and different phase shifting degrees of microwave signals are realized by the dielectric constant of the liquid crystal layer. It should be understood that, after the microwave signal is input to the first electrode and the second electrode by the feeding structure, a differential signal is transmitted to ensure that the microwave signal can be shifted in phase between the first electrode and the second electrode.

In a first aspect, as shown in fig. 1 to 9, an embodiment of the present invention provides a liquid crystal phase shifter, including: a first substrate 10 and a second substrate 20 which are oppositely arranged, and a first electrode 11, a second electrode 21 and a liquid crystal layer 30 which are positioned between the first substrate 10 and the second substrate 20; in particular, a first shielding electrode 12 is arranged on the side of the first substrate 10 facing away from the liquid crystal layer 30, and a second shielding electrode 22 is arranged on the side of the second substrate 20 facing away from the liquid crystal layer 30. Wherein, when the first electrode 11 and the second electrode 21 are applied with voltage to generate electric field, the dielectric constant of the liquid crystal layer 30 is changed to adjust the phase shift degree of the microwave signal; in this process, since the first shielding electrode 12 and the second shielding electrode 22 are respectively disposed on the sides of the first substrate 10 and the second substrate 20 facing away from the liquid crystal layer 30, radiation generated by the first electrode 11 and the second electrode 21 is confined between the first shielding electrode 12 and the second shielding electrode 22, so as to prevent the antenna to which the phase shifter of the present embodiment is applied from being interfered by the radiation.

Therein, in some embodiments of the present invention, the first shielding electrode 12 and the second shielding electrode 22 may be embodied as ground electrodes to confine the radiation generated by the first electrode 11 and the second electrode 21 between the first shielding electrode 12 and the second shielding electrode 22.

In some embodiments of the present invention, as shown in fig. 1-5, the first electrode 11 is disposed on the first substrate 10 on the side close to the liquid crystal layer 30, and the second electrode 21 is disposed on the second substrate 20 on the side close to the liquid crystal layer 30; and the orthographic projections of the first electrode 11 and the second electrode 21 on the first substrate 10 are completely overlapped. At this time, different voltages are applied to the first electrode 11 and the second electrode 21, and a vertical electric field is generated between the two electrodes, so that liquid crystal molecules of the liquid crystal layer 30 are deflected to change the dielectric constant of the liquid crystal layer 30, thereby changing the phase shift degree of the microwave signal.

It should be understood that, in order to protect the signal lines on the first and second substrates 10 and 20, that is, the first passivation layer 41 is disposed on the side of the first electrode 11 close to the liquid crystal layer 30, and the second passivation layer 42 is disposed on the side of the second electrode 21 close to the liquid crystal layer 30.

In some embodiments of the present invention, as shown in fig. 4, in order to maintain the cell thickness of the liquid crystal layer, spacers 50 should be further disposed between the first substrate 10 and the second substrate 20, and preferably, the spacers 50 are uniformly arranged, and it should be understood that an orthographic projection of the spacers 50 on the first substrate 10 does not cover the first electrode 11, and an orthographic projection of the spacers 50 on the second substrate 20 does not cover the second electrode 21.

In some embodiments of the present invention, the thickness and material of the first substrate 10 and the second substrate 20 may be the same. While the following condition should be satisfied for the first substrate 10 (second substrate 20) and the liquid crystal layer 30 to secure a design value of the degree of phase shift of the liquid crystal phase shifter in the present embodiment. The specific conditions are as follows:

wherein epsilon₁Is the dielectric constant of the first substrate 10; epsilon_LCThe dielectric constant of the liquid crystal layer 30; h_glassIs the thickness of the first substrate; h_LCIs the thickness of the liquid crystal layer. Specifically, as shown in fig. 6, fig. 6 is an equivalent circuit diagram of the liquid crystal phase shifter of fig. 3; an equivalent circuit between one of the first electrode 11 and the second electrode 21 and the ground electrode (the first shielding electrode 12 or the second shielding electrode 22) may be equivalent to L0 and C0 per unit length, a coupling capacitance generated between the first electrode 11 and the second electrode 21 may be equivalent to C12, the size of C12 is affected by the filling medium of the first electrode 11 and the second electrode 21, and when the voltages applied to the first electrode 11 and the second electrode 21 are different, the dielectric constant of the liquid crystal layer 30 between the two is different, so that C12 is different; phase velocity Vp of the transmission line microwave signal;

it can be seen from the above formula that under the same transmission line length, different C12 generate phase difference, thereby realizing the phase shift of the microwave signal.

In some embodiments of the present invention, as shown in fig. 7, the liquid crystal phase shifter structure is similar to the liquid crystal phase shifter structure of the previous embodiments, except that the first electrode 11 is disposed on the first substrate 10 side close to the liquid crystal layer 30, and the second electrode 21 is disposed on the second substrate 20 side close to the liquid crystal layer 30; and the orthographic projections of the first electrode 11 and the second electrode 21 on the first substrate 10 partially overlap. The phase shifter of this structure operates in the same manner as the phase shifter described above and will not be described in detail here.

The overlapping area of the orthographic projections of the first electrode 11 and the second electrode 21 on the first substrate 10 can be specifically set according to the phase shifting degree requirement of a specific phase shifter.

In some embodiments of the present invention, as shown in fig. 8, the liquid crystal phase shifter structure is similar to the liquid crystal phase shifter structure of the previous embodiments, except that the first electrode 11 is disposed on the first substrate 10 side close to the liquid crystal layer 30, and the second electrode 21 is disposed on the second substrate 20 side close to the liquid crystal layer 30; and the first electrode 11 and the second electrode 21 are not overlapped on the first substrate 10, when different voltages are applied to the first electrode 11 and the second electrode 21, the first electrode 11 and the second electrode 21 form a fringe electric field to deflect liquid crystal molecules in the liquid crystal layer 30 to change a dielectric constant of the liquid crystal layer 30 to change a phase shift degree of a microwave signal.

In some embodiments of the present invention, if the first electrode 11 is disposed on the first substrate 10 and the second electrode 21 is disposed on the second substrate 20, the distance between the first electrode 11 and the second electrode 21 in the horizontal direction includes, but is not limited to, less than 2 times the width of the first electrode 11, so as to ensure that the first electrode 11 and the second electrode 21 can form a capacitor when different voltages are applied thereto. It should be noted that, in the embodiment of the present invention, the widths of the first electrode 11 and the second electrode 21 are considered to be the same, but the widths of the first electrode 11 and the second electrode 21 may be different. In some embodiments of the present invention, as shown in fig. 9, the structure of the liquid crystal phase shifter is similar to that of the liquid crystal phase shifter in the above-mentioned embodiments, except that the first electrode 11 and the second electrode 21 of the liquid crystal phase shifter can be disposed on the same substrate, that is, the first electrode 11 and the second electrode 21 are disposed on the first substrate 10 or the second substrate 20, and when different voltages are applied to the first electrode 11 and the second electrode 21, they will generate a horizontal electric field to deflect the liquid crystal molecules in the liquid crystal layer 30, so as to change the dielectric constant of the liquid crystal layer 30, and change the phase shifting degree of the microwave signal.

In the phase shifter with such a structure, the distance between the first electrode 11 and the second electrode 21 in the horizontal direction includes, but is not limited to, less than 2 times the width of the first electrode 11, so as to ensure that the first electrode 11 and the second electrode 21 can form a capacitor when different voltages are applied. It should be noted that, in the embodiment of the present invention, the widths of the first electrode 11 and the second electrode 21 are considered to be the same, but the widths of the first electrode 11 and the second electrode 21 may be different. In some embodiments of the present invention, the first substrate 10 and the second substrate 20 may be glass substrates with a thickness of 100-1000 μm, sapphire substrates, polyethylene terephthalate substrates with a thickness of 10-500 μm, triallyl cyanurate substrates, and polyimide transparent flexible substrates.

Specifically, the first substrate 10 and the second substrate 20 may use high-purity quartz glass having extremely low dielectric loss. Compared with a common glass substrate, the first substrate 10 and the second substrate 20 are made of quartz glass, so that the loss of microwaves can be effectively reduced, and the phase shifter has low power consumption and high signal-to-noise ratio.

In some embodiments of the present invention, the material of the first electrode 11 may include metal, and specifically, may be made of metal such as aluminum, silver, gold, chromium, molybdenum, nickel, or iron.

In some embodiments of the present invention, the material of the second electrode 21 may include metal, and specifically, may be made of metal such as aluminum, silver, gold, chromium, molybdenum, nickel, or iron.

In some embodiments of the present invention, the material of the first shielding electrode 12 may include metal, and specifically, may be made of metal such as aluminum, silver, gold, chromium, molybdenum, nickel, or iron.

In some embodiments of the present invention, the material of the second shielding electrode 22 may include metal, and specifically, may be made of metal such as aluminum, silver, gold, chromium, molybdenum, nickel, or iron.

In some embodiments of the present invention, the liquid crystal molecules of the liquid crystal layer 30 are positive liquid crystal molecules or negative liquid crystal molecules, and it should be noted that, when the liquid crystal molecules are positive liquid crystal molecules, an included angle between a long axis direction of the liquid crystal molecules and the second electrode 21 in the embodiments of the present invention is greater than 0 ° and less than or equal to 45 °. When the liquid crystal molecules are negative liquid crystal molecules, the included angle between the long axis direction of the liquid crystal molecules and the second electrode 21 in the embodiment of the invention is larger than 45 degrees and smaller than 90 degrees, so that the microwave propagation constant can be better adjusted after the liquid crystal molecules are deflected, and the phase shifting purpose is achieved.

In some embodiments of the present invention, in order to adjust the microwave transmission constant after the liquid crystal molecules are deflected, the dielectric constant of the long axis direction of the liquid crystal molecules is greater than the dielectric constants of the first substrate 10 and the second substrate 20, wherein the specific choice of the liquid crystal molecule material is selected according to the actual production requirement and the cost of the material.

In some embodiments of the present invention, the thickness of the liquid crystal layer 30 is no greater than 10 μ, and specific liquid crystal layer 30 thicknesses include, but are not limited to, 5-10 μm to ensure that the response time of the liquid crystal layer 30 is sufficiently fast.

In a second aspect, an embodiment of the present invention provides an antenna, which includes any one of the above-mentioned liquid crystal phase shifters. In practical applications, the antenna may further include a carrier unit, such as a carrier plate, and the phase shifter may be disposed on the carrier plate.

It should be noted that the number of the liquid crystal phase shifters included in the antenna is determined according to actual requirements, and the embodiment of the present invention is not particularly limited.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.