A frequency and pattern reconfigurable antenna with parasitic elements of liquid crystal material

Abstract

The application discloses a frequency and directional diagram reconfigurable antenna of liquid crystal material with a parasitic element, comprising a first dielectric substrate, a first orientation layer, a second dielectric substrate, a second orientation layer and a conductive substrate which are arranged in layers; the upper surface of the first dielectric substrate is provided with a metal microstrip transmission line; the lower surface of the first dielectric substrate is provided with a spindle-shaped metal patch, a trapezoidal gradient microstrip transmission line and a rectangular parasitic dipole; the rectangular parasitic dipole is symmetrically arranged on both sides of the spindle-shaped metal patch; the middle part of the second dielectric substrate is hollowed out to form a liquid crystal groove, and the liquid crystal groove is filled with liquid crystal material; the orthographic projection of the spindle-shaped metal patch is located in the liquid crystal groove; and the conductive substrate comprises a complete conductive metal layer which serves as a ground plane. The antenna breaks through the limitation of traditional reconfigurable antennas which can only realize single-index reconfiguration, and realizes the simultaneous reconfiguration of the frequency and the radiation directional diagram of the 5G millimeter wave frequency band.

Description

Technical Field

[0001] This application belongs to the field of antenna technology, specifically referring to a frequency and pattern reconfigurable antenna made of liquid crystal material with parasitic units. Background Technology

[0002] With the rapid development of wireless mobile communication technology, users have placed higher demands on communication equipment, and millimeter-wave antennas, as important components in millimeter-wave band communication systems, have gradually become a research hotspot. Traditional antenna designs are often limited to fixed-frequency band operation modes, making it difficult to flexibly switch communication bands according to actual application scenarios. This limitation significantly restricts the application of antennas in complex communication environments. Simultaneously, there is a growing demand for reconfigurable antennas that can dynamically adjust their radiation characteristics according to system requirements and user needs, thereby improving spectrum utilization. To address these issues, frequency and pattern reconfigurable antennas have emerged, enabling dynamic control of operating frequency and radiation beamwidth based on changing environments and complex communication systems. This helps improve the communication capacity of wireless communication networks and further optimizes communication system performance.

[0003] Currently, antennas mainly utilize four types: electrical control, mechanical control, optical control, and reconfigurable antennas based on tunable materials. However, PIN diodes, varactor diodes, and RF-MEMS switches are unsuitable for high-frequency applications due to excessive insertion loss in the millimeter-wave band. Mechanically controlled reconfigurable antennas suffer from slow response speed, large size, and high power consumption, which limits their widespread application in specific situations. Integrating the laser source for photoconductive switches is challenging, potentially increasing system size and complexity. In contrast, among numerous reconfigurable technologies based on electronic devices, mechanical control, and tunable materials, liquid crystals, as materials with tunable dielectric constants, offer advantages such as high-frequency suitability, low loss, and low cost, making liquid crystal-based reconfigurable millimeter-wave antennas a promising area for research and application.

[0004] However, research on existing liquid crystal-based reconfigurable antennas reveals that liquid crystal-based antenna arrays typically require complex feed networks and suffer from drawbacks such as high profile and high transmission loss. Leaky wave antennas based on liquid crystal materials exhibit limitations in beam reconfigurability and antenna size. Furthermore, most traditional reconfigurable antennas can only achieve reconfiguration for a single metric. Given the current state of liquid crystal material technology and manufacturing processes, liquid crystal antennas still face drawbacks and technical challenges, including narrow impedance bandwidth and the limitation to reconfiguration for only a single metric. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this application provides a frequency and radiation pattern reconfigurable antenna with a liquid crystal material containing parasitic units. This breaks through the limitation of traditional reconfigurable antennas that can only achieve single-index reconfiguration, and achieves simultaneous reconfiguration of frequency and radiation pattern in the 5G millimeter wave band.

[0006] The present invention provides a frequency and pattern reconfigurable antenna for a liquid crystal material with parasitic units, comprising a first dielectric substrate, a first alignment layer, a second dielectric substrate, a second alignment layer, and a conductive substrate stacked together.

[0007] The upper surface of the first dielectric substrate is provided with a metal microstrip transmission line; the lower surface of the first dielectric substrate is provided with a spindle-shaped metal patch, a trapezoidal gradient microstrip transmission line and a rectangular parasitic dipole; the spindle-shaped metal patch is formed by two symmetrical rectangular grooves on both sides of a rectangular metal patch; the rectangular parasitic dipole is symmetrically arranged on both sides of the spindle-shaped metal patch.

[0008] The middle part of the second dielectric substrate is hollowed out to form a liquid crystal cell, which is filled with liquid crystal material; the orthographic projection of the spindle-shaped metal patch is located in the liquid crystal cell;

[0009] The conductive substrate includes a complete conductive metal layer, which serves as a ground plane.

[0010] Furthermore, a metallized via is provided on the first dielectric substrate, and the metal microstrip transmission line located on the upper surface of the first dielectric substrate and the trapezoidal gradient microstrip transmission line located on the lower surface of the first dielectric substrate are connected through the metallized via.

[0011] Furthermore, the trapezoidal gradient microstrip transmission line extends from the midpoint of one long side of the spindle-shaped metal patch to the edge of the first dielectric substrate.

[0012] Furthermore, the rectangular parasitic dipole also includes two PIN diodes, which are respectively disposed between the two arms of the rectangular parasitic dipole.

[0013] Furthermore, both the first dielectric substrate and the second dielectric substrate are high-frequency substrates made of PTFE composite material.

[0014] Furthermore, both the first orientation layer and the second orientation layer are polyimide layers, and the thickness of the first orientation layer and the second orientation layer is 0.01 mm to 0.1 mm.

[0015] Furthermore, liquid crystal injection holes are provided on the first dielectric substrate and the first alignment layer, and the liquid crystal injection holes are located above the liquid crystal tank.

[0016] Furthermore, the thickness of the liquid crystal cell is the same as the thickness of the second dielectric substrate.

[0017] Furthermore, the conductive substrate is an aluminum plate.

[0018] Furthermore, mounting holes are provided on both sides of the first dielectric substrate, the first alignment layer, the second dielectric substrate, the second alignment layer, and the conductive substrate, through which the fixing device is pressed and fixed to secure the antenna.

[0019] The beneficial effects of this invention are as follows: The frequency and radiation pattern reconfigurable antenna of liquid crystal material with parasitic units provided in this application, by combining liquid crystal material and parasitic unit reconfigurable technology, independently controls the dielectric constant and surface current path of the microstrip antenna with external voltage, realizing independent adjustment of the antenna impedance and radiation characteristics. This breaks through the limitation of traditional reconfigurable antennas that can only achieve single-indicator reconfiguration, and achieves simultaneous reconfiguration of frequency and radiation pattern in the 5G millimeter-wave band. The antenna provided in this application has broad application prospects in wireless communication, radar, and remote sensing, and has reference value for theoretical research and engineering applications of liquid crystal material tunable antennas in design, implementation, and testing. Attached Figure Description

[0020] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0021] Figure 1 This is a unfolded diagram of the frequency and radiation pattern reconfigurable antenna structure of the liquid crystal material with parasitic units provided in this embodiment.

[0022] Figure 2 This is a side view of the frequency and pattern reconfigurable antenna of the liquid crystal material with parasitic units provided in this embodiment.

[0023] Figure 3 This is a schematic diagram of the upper surface structure of the first dielectric substrate provided in this embodiment.

[0024] Figure 4 This is a schematic diagram of the lower surface structure of the first dielectric substrate provided in this embodiment.

[0025] Figure 5 This is a schematic diagram of the structure of the second dielectric substrate provided in this embodiment.

[0026] Figure 6 This is a graph showing the measurement data of antenna return loss as a function of voltage provided in this embodiment.

[0027] Figure 7 This is a graph showing the change of the antenna resonant frequency with the applied voltage provided in this embodiment.

[0028] Figure 8 This is the radiation pattern of the XOZ plane of the antenna provided in this embodiment.

[0029] Figure 9 This is the radiation pattern of the antenna's YOZ plane provided in this embodiment.

[0030] Figure 10 This is a data graph showing how the antenna radiation pattern in the XOZ plane changes with the state of the PIN diode, as provided in this embodiment.

[0031] The components in the figure are labeled as follows: 1. First dielectric substrate; 2. First alignment layer; 3. Second dielectric substrate; 4. Second alignment layer; 5. Conductive substrate; 6. Liquid crystal cell; 7. Metal microstrip transmission line; 8. Spindle-shaped metal patch; 9. Rectangular parasitic dipole; 10. Metallized through hole; 11. Liquid crystal injection hole; and 12. Mounting hole. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0033] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0035] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0036] like Figure 1 As shown, this embodiment provides a frequency and pattern reconfigurable antenna for liquid crystal material with parasitic units, including a first dielectric substrate 1, a first alignment layer 2, a second dielectric substrate 3, a second alignment layer 4, and a conductive substrate 5 stacked together; as well as a liquid crystal cell 6, a metal microstrip transmission line 7, a spindle-shaped metal patch 8, a rectangular parasitic dipole 9, a metallized through-hole 10, a liquid crystal injection hole 11, and a mounting hole 12, etc.

[0037] Taking the illustrated viewpoint as an example, the first dielectric substrate 1, the first alignment layer 2, the second dielectric substrate 3, the second alignment layer 4, and the conductive substrate 5 are sequentially stacked. Mounting holes 12 are provided on both sides of each of the first dielectric substrate 1, the first alignment layer 2, the second dielectric substrate 3, the second alignment layer 4, and the conductive substrate 5. The antenna is fixed by holding the fixing device through the mounting holes 12. This allows the first dielectric substrate 1, the first alignment layer 2, the second dielectric substrate 3, the second alignment layer 4, and the conductive substrate 5 to be bonded together layer by layer to form a whole.

[0038] like Figure 3 , Figure 4As shown, a metal microstrip transmission line 7 is disposed on the upper surface of the first dielectric substrate 1. The width of the metal microstrip transmission line 7 can be set to between 2 mm and 2.5 mm (including the endpoint value), and the length can be set to between 4 mm and 7 mm (including the endpoint value). A metallized via 10 is disposed on the metal microstrip transmission line 7, and the diameter of the metallized via 10 can be set to between 1 mm and 2 mm (including the endpoint value). A spindle-shaped metal patch 8, a trapezoidal gradient microstrip transmission line, and a rectangular parasitic dipole 9 are disposed on the lower surface of the first dielectric substrate 1. The spindle-shaped metal patch 8 is formed by two symmetrical rectangular grooves on both sides of a rectangular metal patch. The width of the spindle-shaped metal patch 8 can be set to between 4 mm and 6 mm (inclusive), and the length can be set to between 6.2 mm and 8 mm (inclusive). The width of the rectangular parasitic dipole 9 can be set to between 4 mm and 6 mm (inclusive), and the length can be set to between 3 mm and 5.5 mm (inclusive). The width of the rectangular groove on the top of the spindle-shaped metal patch 8 can be set to between 0.2 mm and 1 mm (inclusive), and the length can be set to between 1 mm and 3 mm (inclusive). One end of the trapezoidal gradient microstrip transmission line is connected to one end of the spindle-shaped metal patch 8, and the trapezoidal gradient microstrip transmission line extends from the midpoint of one long side of the spindle-shaped metal patch 8 to the edge of the first dielectric substrate 1.

[0039] The rectangular parasitic dipole 9 is symmetrically arranged on both sides of the spindle-shaped metal patch 8. The rectangular parasitic dipole 9 also includes two PIN diodes, which are respectively disposed between the two arms of the rectangular parasitic dipole 9. The disconnection and connection of the metal patch between the two arms of the rectangular parasitic dipole 9 can replace the two states of the PIN diodes being on and off.

[0040] The metal microstrip transmission line 7 on the upper surface of the first dielectric substrate 1 and the trapezoidal gradient microstrip transmission line on the lower surface of the first dielectric substrate 1 are both microstrip transmission lines etched with copper. The metal microstrip transmission line 7 on the upper surface of the first dielectric substrate 1 and the trapezoidal gradient microstrip transmission line on the lower surface of the first dielectric substrate 1 are connected through the metallized via 10.

[0041] like Figure 5As shown, a liquid crystal groove 6 is formed by hollowing out the center of the second dielectric substrate 3. The liquid crystal groove 6 serves as a liquid crystal cavity and is filled with liquid crystal material. The width of the liquid crystal groove 6 can be set to between 4 mm and 6 mm (inclusive), and the length can be set to between 11 mm and 14 mm (inclusive). Furthermore, the thickness of the liquid crystal groove 6 is the same as the thickness of the second dielectric substrate 3. The orthographic projection of the spindle-shaped metal patch 8 is located within the liquid crystal groove 6. Liquid crystal injection holes 11 are provided on the first dielectric substrate 1 and the first alignment layer 2. The liquid crystal injection holes 11 are located above the liquid crystal groove 6, allowing liquid crystal material to be directly injected into the liquid crystal groove 6 through the liquid crystal injection holes 11.

[0042] In this embodiment, both the first dielectric substrate 1 and the second dielectric substrate 3 are high-frequency dielectric substrates made of PTFE composite material. Furthermore, the thickness of the first dielectric substrate 1 and the second dielectric substrate 3 is between 0.281 mm and 0.481 mm.

[0043] The first alignment layer 2 is attached below the first dielectric substrate 1, and the second alignment layer 4 is attached above the conductive substrate 5. In this embodiment, both the first alignment layer 2 and the second alignment layer 4 are polyimide layers. Both the first alignment layer 2 and the second alignment layer 4 are formed from a polyimide solution through processes such as spin coating, curing, and friction. The thickness of the first alignment layer 2 and the second alignment layer 4 is 0.01 mm to 0.1 mm.

[0044] The conductive substrate 5 includes a complete conductive metal layer, which serves as a ground plane. The conductive substrate 5 is an aluminum plate or a copper plate. The thickness of the conductive substrate 5 is 3 mm to 9 mm.

[0045] The following provides a preferred structural parameter for this embodiment, including: the thicknesses of the first dielectric substrate 1, the first alignment layer 2, the second dielectric substrate 3, the second alignment layer 4, and the conductive substrate 5 are 0.381 mm, 0.03 mm, 0.381 mm, 0.03 mm, and 7 mm, respectively. Both the first dielectric substrate 1 and the second dielectric substrate 3 are high-frequency dielectric substrates made of Rogers 5880 or other PTFE (polytetrafluoroethylene) composite materials. Both materials have the same dielectric constant and loss tangent, which are 2.2 and 0.0009, respectively. In this embodiment, the first dielectric substrate 1 and the second dielectric substrate 3 have the same substrate thickness. Substrates of different thicknesses can also be selected according to actual needs. Suitable types of substrates can be selected for the first dielectric substrate 1 and the second dielectric substrate 3 based on their different thicknesses.

[0046] Both the first alignment layer 2 and the second alignment layer 4 are formed from polyimide solution through processes such as spin coating, curing, and friction. The dielectric constant and loss tangent of both materials are the same, at 4.3 and 0.004, respectively. The conductive substrate 5 is an aluminum plate, therefore its dielectric constant is 1.

[0047] The liquid crystal injection hole 11 penetrates vertically through the first dielectric substrate 1 and the first alignment layer 2, and can serve to inject liquid crystal and expel air.

[0048] like Figure 3 , Figure 4 As shown, the metal microstrip transmission line 7, the spindle-shaped metal patch 8, the trapezoidal gradient microstrip transmission line, and the rectangular parasitic dipole 9 located on the first dielectric substrate 1 are all formed by etching copper metal onto the upper and lower surfaces of the first dielectric substrate 1 using a PCB etching process, and each has a thickness of 0.035 mm. In this embodiment, the structural dimensions on the first dielectric substrate 1 and the structural dimensions on the second dielectric substrate 3 are related to the resonant frequency of the liquid crystal material. Therefore, in this embodiment, a preferred specific structure parameter is given, wherein the structural dimensions on the first dielectric substrate 1 and the structural dimensions on the second dielectric substrate 3 are set as follows:

[0049] The width of the liquid crystal cell 6 is 5.5 mm and the length is 13 mm;

[0050] The metal microstrip transmission line 7 has a width of 2.2 mm and a length of 5.5 mm;

[0051] The spindle-shaped metal patch 8 has a width of 5.2 mm and a length of 7 mm;

[0052] The rectangular groove above the spindle-shaped metal patch 8 has a width of 0.5 mm and a length of 2.1 mm;

[0053] The rectangular parasitic dipole 9 has a width of 3.9 mm and a length of 3.6 mm;

[0054] The diameter of the metallized through-hole 10 is 1 mm.

[0055] The processed boards are arranged according to Figure 1 The components were assembled and tested using a vector network analyzer and related devices. The resulting graphs show the changes in return loss versus voltage and the changes in resonant frequency versus applied voltage, as shown below. Figure 6 and Figure 7As shown, with the increase of the external control voltage, the center frequency of the antenna shifts towards lower frequencies, continuously shifting from 28.92 GHz to 24.85 GHz, achieving a 14% (4.07 GHz) shift. Throughout the tuning process, the antenna's impedance bandwidth remains essentially constant. Experimental results demonstrate that the antenna with rectangular parasitic elements possesses stable frequency reconfigurability and can provide continuous switching functionality for certain 5G millimeter-wave frequency bands in multiple countries and regions.

[0056] Figure 8 and Figure 9 The images show the radiation patterns of the antenna provided in this embodiment in the XOZ and YOZ planes. It can be seen that the antenna provided in this embodiment has strong directivity, and its radiation pattern remains essentially consistent with changes in the dielectric constant, demonstrating stable radiation performance.

[0057] Figure 10 The radiation pattern of the antenna in the XOZ plane provided in this embodiment was measured. When the liquid crystal is in a free state (i.e., without applied bias voltage) and the diode is in the off state, the -3dB beamwidth of the antenna is 34°; when the diode is in the on state, the -3dB beamwidth of the antenna is 64°. Therefore, the reconfigurable beamwidth range of this antenna is 88%.

[0058] In summary, the broadband frequency and pattern reconfigurable antenna based on liquid crystal material with parasitic dipoles of the present invention not only has a wide impedance bandwidth but also possesses the characteristic of simultaneous frequency and pattern reconfigurability. This invention enables continuous switching of certain 5G millimeter-wave frequency bands in different countries and regions and can also change the radiation beamwidth to help balance information flow between different areas, thereby improving capacity efficiency.

[0059] This application presents a frequency and radiation pattern reconfigurable antenna using liquid crystal material with parasitic units. By combining liquid crystal material and parasitic unit reconfiguration technology, the dielectric constant and surface current path of the microstrip antenna are independently controlled by an external voltage. This achieves independent adjustment of the antenna's impedance and radiation characteristics, breaking through the limitation of traditional reconfigurable antennas that can only achieve single-indicator reconfiguration. It enables simultaneous reconfiguration of both frequency and radiation pattern in the 5G millimeter-wave band. The antenna provided in this application has broad application prospects in wireless communication, radar, and remote sensing, and provides valuable reference for theoretical research and engineering applications in the design, implementation, and testing of tunable antennas using liquid crystal materials.

[0060] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the present invention. Finally, it should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0061] The frequency and pattern reconfigurable antenna of liquid crystal material with parasitic units provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A frequency and pattern reconfigurable antenna for a liquid crystal material with parasitic units, characterized in that, It includes a first dielectric substrate, a first alignment layer, a second dielectric substrate, a second alignment layer, and a conductive substrate stacked together; The upper surface of the first dielectric substrate is provided with a metal microstrip transmission line; the lower surface of the first dielectric substrate is provided with a spindle-shaped metal patch, a trapezoidal gradient microstrip transmission line and a rectangular parasitic dipole; the spindle-shaped metal patch is formed by two symmetrical rectangular grooves on both sides of a rectangular metal patch; the rectangular parasitic dipole is symmetrically arranged on both sides of the spindle-shaped metal patch. The first dielectric substrate has metallized vias, and the metal microstrip transmission line located on the upper surface of the first dielectric substrate and the trapezoidal gradient microstrip transmission line located on the lower surface of the first dielectric substrate are connected through the metallized vias; the trapezoidal gradient microstrip transmission line extends from the midpoint of one long side of the spindle-shaped metal patch to the edge of the first dielectric substrate. The middle part of the second dielectric substrate is hollowed out to form a liquid crystal cell, which is filled with liquid crystal material; the orthographic projection of the spindle-shaped metal patch is located in the liquid crystal cell; The conductive substrate includes a complete conductive metal layer, which serves as a ground plane.

2. The frequency and pattern reconfigurable antenna of liquid crystal material with parasitic units according to claim 1, characterized in that, The rectangular parasitic dipole also includes two PIN diodes, which are respectively disposed between the two arms of the rectangular parasitic dipole.

3. The frequency and pattern reconfigurable antenna of liquid crystal material with parasitic units according to claim 1, characterized in that, Both the first dielectric substrate and the second dielectric substrate are high-frequency substrates made of PTFE composite material.

4. The frequency and pattern reconfigurable antenna of liquid crystal material with parasitic units according to claim 1, characterized in that, Both the first orientation layer and the second orientation layer are polyimide layers, and the thickness of the first orientation layer and the second orientation layer is 0.01 mm to 0.1 mm.

5. The frequency and pattern reconfigurable antenna of liquid crystal material with parasitic units according to claim 1, characterized in that, The first dielectric substrate and the first alignment layer are provided with liquid crystal injection holes, which are located above the liquid crystal cell.

6. The frequency and pattern reconfigurable antenna of liquid crystal material with parasitic units according to claim 5, characterized in that, The thickness of the liquid crystal cell is the same as the thickness of the second dielectric substrate.

7. The frequency and pattern reconfigurable antenna of liquid crystal material with parasitic units according to claim 1, characterized in that, The conductive substrate is an aluminum plate.

8. The frequency and pattern reconfigurable antenna of liquid crystal material with parasitic units according to claim 1, characterized in that, Mounting holes are provided on both sides of the first dielectric substrate, the first alignment layer, the second dielectric substrate, the second alignment layer, and the conductive substrate, and the antenna is fixed by pressing the fixing device through the mounting holes.

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