A reconfigurable planar microwave device based on vanadium dioxide phase change film

Abstract

This invention relates to a redefinable planar microwave device based on vanadium dioxide phase change thin film, belonging to the field of microwave device technology. It includes a phase change patch array, a dielectric substrate, and a metal ground plane connected in sequence. The phase change patch array comprises several uniformly arranged phase change thin film blocks, with conductive sponges between adjacent blocks. One end of the phase change patch array is connected to a transmission line and an input port, and the other end is connected to a reconfigurable transmission line and a reconfiguration port. The phase change thin film blocks, the transmission line, and the reconfigurable transmission line are all made of vanadium dioxide. When the transmission line, the reconfigurable transmission line, and the phase change thin film blocks are heated to 68–72°C in different combinations, the vanadium dioxide undergoes a phase transition, changing from a non-metallic state to a metallic state. At this time, the device surface structure is divided into a phase change region and a non-phase change region. The phase change region effectively replaces the microstrip metal, forming two types of A-shaped planar microstrip patch antennas, two types of microwave planar serpentine inductors, and a planar microstrip capacitor, respectively, thus creating redefinable planar microwave devices.

Description

Technical Field

[0001] This invention belongs to the field of microwave device technology and involves the conversion between various planar microwave functional circuits. Specifically, it is a technical method for realizing the multi-functional conversion and reconfiguration of devices such as antennas, serpentine inductors, and capacitors by utilizing the phase change characteristics of vanadium dioxide (VO2) material under effective temperature control conditions. Background Technology

[0002] With the rapid development of microwave integrated circuits, microstrip lines have been widely used in microwave transmission lines. Microstrip structures have unique characteristics; generally, a specific microstrip structure can only achieve one function. For example, mobile terminal devices have many antennas with different structures distributed on the side to achieve different frequency responses. The low multiplexing rate of this microwave structure makes it difficult to meet today's "miniaturization" integration requirements.

[0003] In recent years, reconfigurable microwave devices have been at the forefront of research. They integrate multiple functional devices into one device and use phase change materials to act as switches to achieve on / off switching or replace local circuit structures to achieve multiple functions, greatly expanding the application range of individual microwave devices. However, such reconfigurable devices have two main problems: (1) From the perspective of device design structure, vanadium dioxide is only used as a temperature control switch. For example, in microwave passive devices that integrate filters, antennas, power dividers and couplers on the same substrate, the connection is selected by vanadium dioxide switching. Such devices still have many device units in microsystems, the reuse rate of microwave devices is low, and there is no practical innovation value. (2) From the perspective of physical heating, the conductivity is changed by the phase change of vanadium dioxide controlled by temperature. The heat often diffuses outward in a ring shape from the heating point. Therefore, accurately heating a fixed area according to the microstrip structure is a technical problem. Summary of the Invention

[0004] In order to realize the conversion, reuse and reconfiguration of the functions of different microwave devices, that is, to realize the redefinability of microwave devices, this invention provides a redefinable microwave device based on phase change materials.

[0005] A redefined planar microwave device based on vanadium dioxide phase change thin film includes a phase change patch array, a dielectric substrate 1, and a metal ground plane 5 connected in sequence.

[0006] The phase change patch array includes nine or more phase change thin film blocks 2 arranged uniformly, and conductive sponge 6 is provided between adjacent phase change thin film blocks 2; the phase change patch array is located in the middle of the dielectric substrate 1, one end of the phase change patch array is connected to one end of the transmission line 3, and the other end of the corresponding phase change patch array is connected to one end of the reconfiguration transmission line 4. The materials of the phase change thin film block 2, the transmission line 3, and the reconstructed transmission line 4 are all vanadium dioxide. An input port 7 is provided on one side edge of the dielectric substrate 1 on one side of the phase change patch array, and the other end of the transmission line 3 is connected to the input port 7; a reconstruction port 8 is provided on the other side edge of the dielectric substrate 1, and the other end of the reconstruction transmission line 4 is connected to the reconstruction port 8. When the transmission line 3, the reconstructed transmission line 4, and several phase change thin film blocks 2 are heated to 68-72°C in different combinations, the vanadium dioxide material undergoes a phase change, transforming from a non-metallic state to a metallic state. At this time, the surface structure of the device is divided into a phase change region and a non-phase change region. The phase change region is equivalent to replacing the microstrip metal, forming two types of A-shaped planar microstrip patch antennas, two types of microstrip planar serpentine inductors, or planar microstrip capacitors that can be redefined as planar microwave devices.

[0007] The further defined technical solution is as follows: The phase change patch array includes twenty phase change thin film blocks 2, forming a rectangular array of four rows and five columns. The middle of the first column is connected to one end of the transmission line 3, and the middle of the fifth column is connected to one end of the reconfiguration transmission line 4.

[0008] The material of the dielectric substrate 1 is epoxy resin board (FR4).

[0009] The metal grounding plate 5 is made of copper.

[0010] The conductive sponge 6 is a conductive sponge strip with a surface resistance of less than or equal to 0.05 Ω / sp and a thermal conductivity of 0.034 W / m·°C, which serves to conduct electricity and insulate heat.

[0011] When the heating transmission line 3 and several phase change film blocks 2 are heated to 68–72°C, the vanadium dioxide material undergoes a phase transition, changing from a nonmetallic state to a metallic state. The transmission line 3 is equivalent to an impedance transformation line, and the several phase change film blocks 2 are equivalent to a radiation rectangle. When the input port 7, transmission line 3, and phase change thin film block 2 are connected in sequence, they form a T-shaped planar microstrip patch antenna with a resonant frequency of 3.3 GHz.

[0012] When the reconstructed transmission line 4 and several phase change thin film blocks 2 are heated to 68-72°C, the vanadium dioxide material undergoes a phase transition, changing from a non-metallic state to a metallic state. The reconstructed transmission line 4 is equivalent to an impedance transformation line, and the several phase change thin film blocks 2 are equivalent to a radiating rectangle. When the reconstructed port 8, the reconstructed transmission line 4, and the phase change thin film blocks 2 are connected in sequence, a T-shaped planar microstrip patch antenna with a resonant frequency of 3.8-3.9 GHz is formed.

[0013] When the heating transmission line 3, the reconstructed transmission line 4, and several phase change thin film blocks 2 are heated to 68–72°C, the vanadium dioxide material undergoes a phase change, transforming from a non-metallic state to a metallic state. The transmission line 3 and the reconstructed transmission line 4 are equivalent to impedance transformation lines, and the several phase change thin film blocks 2 are equivalent to serpentine microstrip lines. One end of the serpentine microstrip line is connected to the transmission line 3 and the input port 7 in sequence, and the other end of the serpentine microstrip line is connected to the reconstructed transmission line 4 and the reconstructed port 8 in sequence, forming a microwave planar serpentine inductor with an inductance value ranging from 12 to 30 nanohenries.

[0014] When the heating transmission line 3, the reconstructed transmission line 4, and the several phase change thin film blocks 2 are heated to 68-72°C, the vanadium dioxide material undergoes a phase change, transforming from a non-metallic state to a metallic state. The transmission line 3 and the reconstructed transmission line 4 are equivalent to impedance transformation lines, and the several phase change thin film blocks 2 are equivalent to serpentine microstrip lines with a different structure than the above. One end of the serpentine microstrip line is connected to the transmission line 3 and the input port 7 in sequence, and the other end of the serpentine microstrip line is connected to the reconstructed transmission line 4 and the reconstructed port 8 in sequence, forming a microwave planar serpentine inductor with an inductance value ranging from 13 to 23 nanohenries.

[0015] When the heating transmission line 3, the reconstruction transmission line 4, and several phase change thin film blocks 2 are heated to 68-72°C, the vanadium dioxide material undergoes a phase change, transforming from a non-metallic state to a metallic state. The transmission line 3 and the reconstruction transmission line 4 are equivalent to impedance transformation lines, and the several phase change thin film blocks 2 are equivalent to microstrip capacitors. One end of the microstrip capacitor is connected to the transmission line 3 and the input port 7 in sequence, and the other end is connected to the reconstruction transmission line 4 and the reconstruction port 8 in sequence, forming a planar microstrip capacitor.

[0016] The beneficial technical effects of this invention are reflected in the following aspects: 1. Existing microwave reconfigurable devices enable the reconfiguration of functions such as antennas, filters, and power dividers. The reconfigurable device proposed in this invention not only enables the frequency reconfiguration of antennas and the inductance value reconfiguration of planar serpentine inductors under the same device, but also adds the function of microwave planar capacitance in two-port networks.

[0017] 2. Existing technologies using phase change materials (PCCs) to reconfigure microwave circuits and devices treat PCCs as switches, pre-designing different functional modules on the same circuit board and using switches to select which modules function. This results in a large overall circuit area or volume, failing to achieve true miniaturization of microwave circuits. This invention, drawing inspiration from the "pixel" principle in image processing, proposes using an array of PCC thin-film units to heat specific areas and form specific microwave structures. This achieves high reusability of the same circuit structure; for example, some PCC thin-film units function in all three functional reconfigurations. Therefore, this design approach is fundamentally different from existing technologies, significantly reducing the overall circuit area and greatly improving device integration.

[0018] 3. Existing vanadium dioxide-based reconfigurable microwave devices suffer from difficulty in achieving precise point-to-point heating due to thermal radiation diffusion, making it impossible to achieve an equivalent ideal topology. This invention addresses this technical challenge by: firstly, relatively increasing the size of the phase change thin film unit, thus balancing the heatability of the unit's temperature with the designability of the microwave device's size; and secondly, using conductive sponges to separate the phase change thin film units, which not only conduct electricity but also isolate heat propagated from other thin film units. Compared to previous design approaches, this significantly improves the temperature controllability of microwave devices based on phase change materials. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the device structure of the present invention.

[0020] Figure 2 This is a top view of the device structure and a diagram showing the dimensions of the substrate of the present invention.

[0021] Figure 3 This is a side view of the device structure and a diagram showing the height dimensions of the device according to the present invention.

[0022] Figure 4 A diagram showing the internal dimensions of a redefined device.

[0023] Figure 5 This is a schematic diagram of a U-shaped planar microstrip patch antenna with a resonant frequency of 3.3 GHz.

[0024] Figure 6 This is the equivalent microstrip structure of a T-shaped planar microstrip patch antenna with a resonant frequency of 3.3 GHz.

[0025] Figure 7 This is a schematic diagram of a U-shaped planar microstrip patch antenna with a resonant frequency of 3.8–3.9 GHz.

[0026] Figure 8 This is the equivalent microstrip structure of a T-shaped planar microstrip patch antenna with a resonant frequency of 3.8–3.9 GHz.

[0027] Figure 9 This is a schematic diagram of a microwave planar serpentine inductor with an inductance value ranging from 12 to 30 nanohenries.

[0028] Figure 10 This is the equivalent microstrip structure of a microwave planar serpentine inductor with an inductance value ranging from 12 to 30 nanohenries.

[0029] Figure 11 This is a schematic diagram of a microwave planar serpentine inductor with an inductance value ranging from 13 to 23 nanohenries.

[0030] Figure 12This is the equivalent microstrip structure of a microwave planar serpentine inductor with an inductance value ranging from 13 to 23 nanohenries.

[0031] Figure 13 This is a schematic diagram of the structure for realizing a planar microstrip capacitor according to the present invention.

[0032] Figure 14 This invention provides an equivalent microstrip structure for realizing a planar microstrip capacitor.

[0033] Figure 15 The diagram shows the return loss of a U-shaped planar microstrip patch antenna with a resonant frequency of 3.3 GHz.

[0034] Figure 16 The diagram shows the return loss of a U-shaped planar microstrip patch antenna with a resonant frequency of 3.8–3.9 GHz.

[0035] Figure 17 The diagram shows the inductance values ​​of a microwave planar serpentine inductor with an inductance range of 12 to 30 nanohenries.

[0036] Figure 18 The diagram shows the inductance values ​​of a microwave planar serpentine inductor with an inductance range of 13 to 23 nanohenries.

[0037] Figure 19 This is a diagram showing the capacitance values ​​of the planar microstrip capacitor as described in this invention.

[0038] In the diagram above, the numbers are: 1. Dielectric substrate; 2. Phase change thin film block; 3. Transmission line; 4. Reconstruction transmission line; 5. Metal ground plane; 6. Conductive sponge; 7. Input port; 8. Reconstruction port. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example 1

[0040] See Figure 1 and Figure 2 A redefined planar microwave device based on vanadium dioxide (VO2) phase change thin film includes a phase change patch array, a dielectric substrate 1, and a metal ground plane 5 connected in sequence.

[0041] The phase change patch array consists of twenty phase change thin film blocks 2 arranged in a rectangle of four rows and five columns, with conductive sponges 6 installed between adjacent phase change thin film blocks 2. The phase change patch array is located in the middle of the dielectric substrate 1. One end of the transmission line 3 is connected to the middle of the outermost column on one side of the phase change patch array, and the other end of the transmission line 3 is connected to the input port 7. Correspondingly, one end of the reconstruction transmission line 4 is connected to the middle of the outermost column on the other side of the phase change patch array, and the other end of the reconstruction transmission line 4 is connected to the reconstruction port 8. The input port 7 is fixedly installed on one edge of the dielectric substrate 1, and the reconstruction port 8 is fixedly installed on the other edge of the dielectric substrate 1.

[0042] The phase change film block 2, transmission line 3, and reconstructed transmission line 4 are all made of vanadium dioxide. When the temperature rises to 68–72°C, vanadium dioxide changes from an insulator to a conductor. Phase change film blocks 2 with different conductivity properties constitute phase change and non-phase change regions. The phase change region effectively replaces the microstrip metal, and the non-phase change region effectively replaces air. Different microstrip structures achieve different microstrip functions. The changes in conductivity of transmission line 3 and reconstructed transmission line 4 affect the switching on and off of transmission. The dielectric substrate 1 is made of epoxy resin board (FR4), and the metal ground plane 5 is made of copper. The phase change film blocks 2 are separated by conductive sponge 6. The conductive sponge has a surface resistance of less than or equal to 0.05 Ω / sp and a thermal conductivity of 0.034 W / m·°C, serving to conduct electricity and insulate against heat.

[0043] For previous erasable planar microwave devices based on vanadium dioxide, the phase change film (PCT) film was very small, and the achievable device structure had already realized functional reconfiguration such as antenna-filter-power divider. However, due to thermal radiation diffusion, it was difficult to achieve precise point-to-point heating of the PCT film, and therefore it was impossible to achieve an ideal edge-smooth topology. To address this technical challenge, this invention makes the following improvements: First, it relatively increases the size of the PCT unit, so that the temperature within the unit can be heated and the designability of the microwave device size can be balanced; second, conductive sponges are used to separate the PCT units, which not only conduct electricity but also isolate the heat propagated from other PCT units. Compared with the previous design approach, this significantly improves the temperature controllability of microwave devices based on phase change materials.

[0044] See Figure 2 , Figure 3 and Figure 4 When the center frequency wavelength is λ, the length L of the dielectric substrate 1 b 0.5λ, width W b 0.37λ, thickness H b The phase change thin film block 2 and the conductive sponge 6 are 1 mm thick, with a thickness H. f1 The thickness is 0.01–0.1 mm. The length and width of the metal ground plane 5 are equal to the length and width of the dielectric substrate 1, and the thickness H is... f0 The length L of transmission line 3 is 0.01-0.03 mm. f1 It is 9.05mm long and has a width of W. f1 The length L of the reconstructed transmission line 4 is 0.8mm. f2 It is 9.05mm in diameter and has a width of W. f2 The width is 1.75mm; the width of input port 7 and reconfiguration port 8 is W. z0 It is 1.86mm.

[0045] This invention uses sapphire with a thickness of 0.5 mm as a substrate to deposit vanadium dioxide. Compared with conventional microstrip devices, the metal conductor layer is replaced with a vanadium dioxide (VO2) thin film layer with a thickness of 0.01 to 0.1 mm.

[0046] The core of device fabrication lies in preparing high-quality phase change thin films. The specific processing steps for phase change thin film block 2 are as follows: 1. Substrate polishing The sapphire dielectric substrate blank is subjected to coarse grinding and fine grinding to obtain a substrate whose thickness, surface uniformity and surface finish meet the requirements of vapor deposition, i.e., dielectric substrate; 2. Coating Under argon (Ar) sputtering conditions of 40 Sccm gas flow rate, 550℃ furnace temperature, and 0.40 kPa sputtering pressure, a vanadium dioxide (VO2) phase change film with a thickness of 0.005 mm was deposited on a sapphire dielectric substrate. After annealing in a nitrogen atmosphere, a phase change film block 2 with a thickness of 0.01–0.1 mm was obtained. The surface was observed under a microscope, and a region with uniform grain sputtering was selected and cut out. The vanadium dioxide (VO2) surface was attached to the dielectric substrate 1 (epoxy resin board) with conductive gel and arranged uniformly. The phase change film block 2 was separated by conductive sponge 6. The planar dimensions of the phase change film block 2 unit are 4 mm × 4 mm, and the planar dimensions of the conductive sponge 6 are 4 mm × 0.3 mm.

[0047] In previous studies on vanadium dioxide device fabrication, the process mainly involved depositing a vanadium dioxide thin film of the desired shape onto a substrate using a mask. However, due to uncontrollable factors in experimental conditions (inconsistencies in furnace pressure, temperature, target firing direction and distance, etc.), the deposited vanadium dioxide thin film was not uniform, generally exhibiting a thicker center and thinner edges, which affected the conductivity of vanadium dioxide and consequently the working performance of the device.

[0048] The innovation of this invention lies in the following: a vanadium dioxide thin film is deposited on the entire substrate, and then the film with uniform vanadium dioxide crystal orientation is observed under a microscope and cut into blocks. The film is then bonded to the dielectric substrate 1 with conductive gel. This method ensures the quality of the prepared vanadium dioxide and enables the device to achieve better performance in the microwave field.

[0049] The first device is a planar microwave patch antenna. See Figure 5 Heating transmission line 3 and Figure 5 When the phase change film block 2, shown in the shaded area, reaches 68℃~72℃, the vanadium dioxide material undergoes a phase transition, changing from a non-metallic state to a metallic state. Transmission line 3 is equivalent to an impedance transformation line. Figure 5 The phase change thin film block 2, shown in the shaded area, is equivalent to a radiating rectangle. See also... Figure 6The input port 7, transmission line 3, and radiating rectangle are connected in sequence to form a planar microstrip patch antenna with a resonant frequency of 3.3 GHz.

[0050] The equivalent microstrip dimensions were obtained through calculation and optimization: the length L0 of the radiating rectangle is 21.2 mm ± 0.3 mm, and the width W0 is 16.9 mm ± 0.3 mm; the length L of the impedance transformation line is... f1 It is 9.05mm ± 0.3mm, and the width is W. f1 The width of input port 7 is 0.8mm ± 0.3mm, and the diameter is W. z0 It is 1.86mm.

[0051] When the temperature of the phase change film changes from room temperature to 68℃~72℃, the conductivity of the phase change film changes by five orders of magnitude (the conductivity before the phase change is in the single digits, and the conductivity after the phase change is as high as 10). 6 The non-heated areas remain at room temperature.

[0052] See Figure 15 When the phase change film is heated to achieve the above-mentioned microstrip structure, it can be seen from the antenna return loss diagram that the antenna in this embodiment 1 operates at 3.3 GHz and achieves the basic functions of the antenna well. Example 2

[0053] The second device is a frequency-reconfigurable planar microwave patch antenna, and the material and basic dimensions of the second device are the same as those in Example 1.

[0054] See Figure 7 When the reconstructed transmission line 4 and the shaded phase change film block 2 are heated to 68℃~70℃, the vanadium dioxide material undergoes a phase transition, changing from a nonmetallic state to a metallic state. The reconstructed transmission line 4 is equivalent to an impedance transformation line, and the shaded phase change film block 2 is equivalent to a radiating rectangle; see also Figure 8 A planar microstrip patch antenna with a resonant frequency of 3.8 to 3.9 GHz is formed by sequentially connecting reconfiguration port 8, reconfiguration transmission line 4, and radiating rectangle.

[0055] The equivalent microstrip dimensions were obtained through calculation and optimization: the length L1 of the radiating rectangle is 17.2mm ± 0.3mm, and the width W1 is 16.9mm ± 0.3mm; the length L of the impedance transformation line is... f2 It is 9.05mm ± 0.3mm, and the width is W. f2 The width of the reconstructed port 8 is 1.75mm ± 0.3mm. z0 It is 1.86mm.

[0056] See Figure 16When the phase change film is heated to achieve the above-mentioned microstrip structure, it can be seen from the antenna return loss diagram that the antenna of this embodiment 2 operates at 3.8 to 3.9 GHz, and achieves the basic functions of the antenna and the frequency reconfigurable function well. Example 3

[0057] The third device is a microstrip serpentine inductor, and its material and basic dimensions are the same as those in Example 1.

[0058] See Figure 9 When the heating transmission line 3, the reconstruction transmission line 4, and the shaded phase change film block 2 are heated to 68°C–72°C, the vanadium dioxide material undergoes a phase transition, changing from a nonmetallic state to a metallic state. Transmission line 3 and the reconstruction transmission line 4 are equivalent to impedance transformation lines, and the shaded phase change film block 2 is equivalent to a serpentine microstrip line. (See [link to relevant documentation]). Figure 10 L2 is 12.6mm ± 0.3mm, and W2 is 4.3mm ± 0.3mm. The input port 7, transmission line 3, serpentine microstrip line, reconfiguration transmission line 4, and reconfiguration port 8 are connected in sequence to form a microwave planar serpentine inductor with an inductance range of 12 to 30 nanohenries.

[0059] See Figure 17 When the microstrip structure is achieved by heating the phase change thin film, an inductance value of 12 to 30 nanohenries can be achieved at 0.5 GHz using the inductance extraction formula, and the inductance curve is good. Example 4

[0060] The fourth device is a reconstructed microstrip serpentine inductor, and its material and basic dimensions are the same as those in Example 1.

[0061] See Figure 11 When the heating transmission line 3, the reconstruction transmission line 4, and the shaded phase change film block 2 are heated to 68°C–72°C, the vanadium dioxide material undergoes a phase transition, changing from a nonmetallic state to a metallic state. Transmission line 3 and the reconstruction transmission line 4 are equivalent to impedance transformation lines, and the shaded phase change film block 2 is equivalent to a serpentine microstrip line with a different structure. (See [link to relevant documentation]). Figure 12 L3 is 12.6mm ± 0.3mm, and W3 is 8.3mm ± 0.3mm. The input port 7, transmission line 3, serpentine microstrip line, reconfiguration transmission line 4, and reconfiguration port 8 are connected in sequence to form a microwave planar serpentine inductor with an inductance range of 13 to 23 nanohenries.

[0062] See Figure 18 When the microstrip structure is achieved by heating the phase change thin film, an inductance value of 13 to 23 nanohenries can be achieved at 0.55 GHz using the inductance extraction formula. This achieves reconfigurable inductance value and a good inductance curve. Example 5

[0063] The fifth device is a planar microstrip capacitor, and the material and basic dimensions of the fifth device are the same as those in Example 1.

[0064] See Figure 13 When the heating transmission line 3, the reconstruction transmission line 4, and the shaded phase change film block 2 are heated to 68℃~72℃, the vanadium dioxide material undergoes a phase transition, changing from a nonmetallic state to a metallic state. Transmission line 3 and the reconstruction transmission line 4 are equivalent to impedance transformation lines, and the shaded phase change film block 2 is equivalent to a planar microstrip capacitor. (See [link to relevant documentation]). Figure 14 L4 is 8.3mm ± 0.3mm, W4 is 16.9mm ± 0.3mm, and L5 is 4mm ± 0.3mm. The planar microstrip capacitor is formed by sequentially connecting input port 7, transmission line 3, microstrip capacitor, reconfiguration transmission line 4, and reconfiguration port 8.

[0065] See Figure 19 When the microstrip structure is achieved by heating the phase change thin film, a capacitance value of 10 to 200 picofarads is achieved at 0.8 GHz using the capacitance extraction formula, and the capacitance curve is good.

[0066] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A redefinable planar microwave device based on vanadium dioxide phase change thin film, comprising a phase change patch array, a dielectric substrate (1), and a metal ground plane (5) connected in sequence, characterized in that: The phase change patch array includes 20 uniformly arranged phase change thin film blocks (2) forming a rectangular array of four rows and five columns, with conductive sponges (6) between adjacent phase change thin film blocks (2); the phase change patch array is located in the middle of the dielectric substrate (1), one end of the phase change patch array is connected to one end of the transmission line (3), and the other end of the corresponding phase change patch array is connected to one end of the reconstructed transmission line (4); The materials of the phase change thin film block (2), the transmission line (3), and the reconstructed transmission line (4) are all vanadium dioxide; An input port (7) is provided on one side edge of the dielectric substrate (1) on one side of the phase change patch array, and the other end of the transmission line (3) is connected to the input port (7); a reconstruction port (8) is provided on the other side edge of the dielectric substrate (1), and the other end of the reconstruction transmission line (4) is connected to the reconstruction port (8). When the transmission line (3), the reconstructed transmission line (4), and 20 phase change thin film blocks (2) are heated to 68-72°C with different combinations, the vanadium dioxide material undergoes a phase change, transforming from a non-metallic state to a metallic state. At this time, the surface structure of the device is divided into a phase change region and a non-phase change region. The phase change region is equivalent to replacing the microstrip metal, forming two types of A-shaped planar microstrip patch antennas, two types of microstrip planar serpentine inductors, and planar microstrip capacitors, respectively, which are redefinable planar microwave devices.

2. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: In the rectangular array of four rows and five columns, the middle of the first column is connected to one end of the transmission line (3), and the middle of the fifth column is connected to one end of the reconstructed transmission line (4).

3. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: The dielectric substrate (1) is made of epoxy resin board (FR4).

4. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: The metal ground plane (5) is made of copper.

5. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: The conductive sponge (6) is a conductive sponge strip with a surface resistance of less than or equal to 0.05Ω / sp and a thermal conductivity of 0.034W / m·degree, which serves to conduct electricity and insulate heat.

6. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: The phase change region includes an impedance transformation line formed by the transmission line (3) and a radiating rectangle formed by connecting multiple phase change thin film blocks (2) on the side of the phase change patch array close to the transmission line (3). The multiple phase change thin film blocks (2) are connected to the input port (7) through the transmission line (3) to form a T-shaped planar microstrip patch antenna with a resonant frequency of 3.3 GHz.

7. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: The phase transition region includes an impedance transformation line formed by the reconstructed transmission line (4) and a radiating rectangle formed by connecting multiple phase transition thin film blocks (2) in the phase transition patch array near the reconstructed transmission line (4). The multiple phase transition thin film blocks (2) are connected to the reconstructed port (8) through the reconstructed transmission line (4) to form a T-shaped planar microstrip patch antenna with a resonant frequency of 3.8~3.9GHz.

8. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: The phase transition region includes a first impedance transformation line formed by the transmission line (3), a second impedance transformation line formed by the reconstructed transmission line (4), and a serpentine microstrip line formed by connecting multiple phase transition thin film blocks (2) located in the middle of the phase transition patch array. One end of the serpentine microstrip line is connected to the transmission line (3) and the input port (7) in sequence, and the other end is connected to the reconstructed transmission line (4) and the reconstructed port (8) in sequence, forming a microwave planar serpentine inductor with an inductance value range of 12~30 nanohenries.

9. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: The phase transition region includes a first impedance transformation line formed by the transmission line (3), a second impedance transformation line formed by the reconstructed transmission line (4), and a serpentine microstrip line formed by connecting multiple phase transition thin film blocks (2) located in the middle of the phase transition patch array. One end of the serpentine microstrip line is connected to the transmission line (3) and the input port (7) in sequence, and the other end is connected to the reconstructed transmission line (4) and the reconstructed port (8) in sequence, forming a microwave planar serpentine inductor with an inductance value range of 13 to 23 nanohenries.

10. The redefinable planar microwave device based on vanadium dioxide phase change thin film according to claim 1, characterized in that: The phase transition region includes a first impedance transformation line formed by the transmission line (3), a second impedance transformation line formed by the reconstructed transmission line (4), and a microstrip capacitor formed by connecting multiple phase transition thin film blocks (2) located in the middle of the phase transition patch array. One end of the microstrip capacitor is connected to the transmission line (3) and the input port (7) in sequence, and the other end is connected to the reconstructed transmission line (4) and the reconstructed port (8) in sequence, thus forming a planar microstrip capacitor.

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