Flexible deformable metasurface based on variable capacitance diode space dynamic phase compensation

Abstract

The invention discloses a flexible deformable metasurface based on variable capacitance diode space dynamic phase compensation. The flexible deformable metasurface comprises a flexible deformable metasurface unit; the flexible deformable metasurface unit is divided into five layers which are a first copper layer, a first polyimide layer, a second copper layer, a second polyimide layer and a third copper layer in sequence from top to bottom; the first copper layer comprises a variable capacitance diode, a first copper vertical line, a second copper vertical line, a first copper transverse line and a second copper transverse line; the first copper vertical wire and the second copper vertical wire are arranged in parallel; a first copper transverse line is placed in the middle of the first copper vertical line, and a second copper transverse line is placed in the middle of the second copper vertical line; the first copper transverse line and the second copper transverse line are connected through a variable capacitance diode; the second copper layer and the third copper layer are connected through a switch to form a direct current bias circuit. According to the invention, dynamic electromagnetic wave regulation and control of the flexible deformable metasurface are realized through space dynamic phase compensation of the variable capacitance diode.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic metamaterials, and more particularly to a flexible deformable metasurface based on spatial dynamic phase compensation of varactor diodes. Background Art

[0002] In the fields of military aerospace equipment, battlefield penetration, and strategic reconnaissance, the intelligentization and dynamic adaptability of stealth technology have become key breakthroughs in improving equipment survivability, particularly in scenarios such as drone penetration, submarine silent navigation, and stealth fighter battlefield survival. Achieving conformal integration of electromagnetic stealth with complex curved platforms would significantly reduce the multi-band detectability of targets and potentially overcome the recognition mechanisms of existing polarization-agile radars, facilitating the development of all-weather, full-spectrum active defense systems.

[0003] Metasurface technology, which uses subwavelength structures to coordinate the phase, polarization, and amplitude of electromagnetic waves, has become a research hotspot in the field of electromagnetic stealth. Based on material properties, these technologies are primarily divided into two categories: rigid stealth metasurfaces and flexible stealth metasurfaces. However, both categories have drawbacks. For example, while rigid stealth metasurfaces offer broadband absorption, their complex processing and high surface density prevent them from conforming to curved surfaces, increasing equipment weight and fuel consumption. Traditional flexible stealth metasurfaces, while bendable, have limited absorption bandwidths, and long-term deformation can easily cause the conductive layer to fracture or oxidize and fail. In particular, traditional designs typically target specific polarization directions and are unable to simultaneously process multi-polarization signals. When the enemy employs circular or elliptical polarization for detection, the RCS (radar cross section) of existing isotropic metasurfaces decreases, rendering their stealth ineffective.

[0004] Furthermore, existing dynamic control schemes rely on real-time feedback from external sensors (such as fiber Bragg gratings) and complex algorithms to calculate phase compensation. This leads to bottlenecks such as response delays and poor environmental adaptability, resulting in insufficient phase compensation accuracy. Therefore, current research on electromagnetic stealth metasurfaces must not only meet the requirements of lightweight and broadband compatibility, but also achieve polarization-insensitive, dynamically reconfigurable intelligent response capabilities. Summary of the Invention

[0005] The purpose of the present invention is to provide a flexible deformable metasurface based on spatial dynamic phase compensation of varactor diodes, and dynamic electromagnetic wave control of the flexible deformable metasurface is achieved through spatial dynamic phase compensation of varactor diodes.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A flexible deformable metasurface based on spatial dynamic phase compensation of a varactor diode, wherein the flexible deformable metasurface unit is divided into five layers, namely, a first copper layer, a first polyimide layer, a second copper layer, a second polyimide layer, and a third copper layer from top to bottom;

[0008] The first copper layer includes a copper metasurface shape unit and a varactor diode; the copper metasurface shape unit includes: a first copper vertical line, a second copper vertical line, a first copper horizontal line, and a second copper horizontal line; the first copper vertical line and the second copper vertical line are placed in parallel; the first copper horizontal line is placed in the middle of the first copper vertical line, and the second copper horizontal line is placed in the middle of the second copper vertical line; the first copper horizontal line and the second copper horizontal line are respectively placed perpendicular to the first copper vertical line; the first copper horizontal line and the second copper horizontal line are connected via the varactor diode;

[0009] The second copper layer and the third copper layer are connected by a switch array to form a DC bias circuit.

[0010] Furthermore, the flexible deformable metasurface unit is further provided with a first copper pillar and a second copper pillar, wherein the first copper pillar sequentially penetrates the first polyimide layer, the second copper layer, and the second polyimide layer, and connects the first copper horizontal line to the third copper layer;

[0011] The second copper pillar penetrates the first polyimide layer and connects the second copper horizontal line to the second copper layer; the first copper pillar and the second copper pillar are respectively arranged on the left and right sides of the varactor diode; the first copper pillar and the second copper layer are insulated;

[0012] The flexible deformable metasurface unit constructs a closed-loop bias circuit through the first copper pillar and the second copper pillar.

[0013] Furthermore, the insulation distance between the first copper pillar and the second copper layer is 0.05 mm; the first copper pillar and the second copper pillar are respectively arranged on the left and right sides of the varactor diode, the distance between the first copper pillar and the second copper pillar is 3 mm, and the radius of the first copper pillar and the second copper pillar are both 0.15 mm.

[0014] Furthermore, the switch array is composed of four single-pole double-throw switches, each of which is implemented by a field-effect transistor. The gate of the field-effect transistor serves as the control terminal, and the source and drain serve as the common terminal and selection terminal of the single-pole double-throw switch respectively; by applying different level signals to the gate, the on and off states of the source and drain are controlled to realize the switching function.

[0015] Furthermore, the third copper layer is a strip microstrip line with a width of 0.8 mm.

[0016] Furthermore, the size of the flexible deformable metasurface unit is 16×16 mm.

[0017] Furthermore, the thickness of the copper metasurface shape unit of the first copper layer is 0.035 mm; the total length and total width of the first copper layer are both 10 mm, the gap between the first copper vertical line and the first copper horizontal line is 1 mm; and the gap between the second copper vertical line and the second copper horizontal line is 1 mm.

[0018] Furthermore, the thickness of the first polyimide layer is 0.8 mm, the second copper layer is a metal reflective layer with a thickness of 0.1 mm; and the thickness of the second polyimide layer is 0.5 mm.

[0019] Furthermore, the resistance of the varactor diode is 2.5Ω, and the inductance is 0.7nH.

[0020] Furthermore, when the flexible deformable metasurface unit receives an external deformation instruction, it queries the deformation-phase mapping database according to the deformation parameters to obtain the target phase At this time, the target phase The corresponding capacitance reduction is The target capacitance value is obtained as:

[0021]

[0022] Among them, C target is the target capacitance value, C0 is the maximum initial voltage of the varactor diode, that is, the capacitance value when the bias voltage is 0V;

[0023] The relationship between the capacitance of a varactor diode and the reverse bias voltage V is:

[0024]

[0025] Among them, C j0 (V) is the relationship between capacitance and reverse bias voltage V, V is the reverse bias voltage, V j is the junction voltage, V j =0.7V; m is the gradient coefficient;

[0026] Substituting (1) into (2), taking m = 0.5, we can get the driving voltage V c :

[0027]

[0028] According to the specific embodiments provided by the present invention, the present invention has the following technical effects compared with the prior art:

[0029] The flexible, deformable metasurface unit of the present invention integrates a copper metasurface shape unit and a varactor diode, enabling real-time adjustment of the varactor diode capacitance via a bias voltage to compensate for phase deviation caused by deformation. Furthermore, through the unique metasurface structure and the symmetrical design of the H-shaped structure, the present invention ensures symmetry and precision in phase compensation, eliminates reflection differences between electromagnetic waves of different polarization directions, and exhibits polarization insensitivity. Furthermore, the combination of the second and third copper layers effectively broadens the operating bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0031] The flexible deformable metasurface based on spatial dynamic phase compensation of varactor diodes of the present invention will be further described below with reference to the accompanying drawings;

[0032] Figure 1 3D schematic diagram of the flexible deformable metasurface based on spatial dynamic phase compensation of varactor diodes according to the present invention;

[0033] Figure 2 2 is a schematic side structural diagram of a flexible deformable metasurface based on spatial dynamic phase compensation of a varactor diode according to the present invention;

[0034] Figure 3 Schematic diagram of the overall structure of the flexible deformable metasurface based on spatial dynamic phase compensation of varactor diodes according to the present invention;

[0035] Figure 4 is a functional diagram of an experiment using the flexible deformable metasurface of the present invention; wherein, Figure 4 (a) is a functional diagram of using parallel light to illuminate the bare ground; Figure 4 (b) is a functional diagram of using parallel light to illuminate the ground with an object placed on it; Figure 4 (c) in the figure is a functional diagram of the ground where an object covered by a flexible metasurface is placed using parallel light.

[0036] Explanation of the accompanying drawings: 1. First copper vertical line; 2. Second copper vertical line; 3. First copper horizontal line; 4. Second copper horizontal line; 5. Varactor diode; 6. First polyimide layer; 7. Second copper layer; 8. Second polyimide layer; 9. Third copper layer; 10. First copper column; 11. Second copper column. DETAILED DESCRIPTION

[0037] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0038] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below with reference to the accompanying drawings.

[0039] Example 1

[0040] like Figure 1 Shown and Figure 2 As shown, the present invention provides a flexible deformable metasurface based on spatial dynamic phase compensation of varactor diodes, comprising: a flexible deformable metasurface unit;

[0041] like Figure 3 As shown, the metasurface unit is divided into 5 layers, which are, from top to bottom, a first copper layer, a first polyimide layer 6, a second copper layer 7, a second polyimide layer 8 and a third copper layer 9;

[0042] The first copper layer is an H-shaped copper layer, including a copper metasurface shape unit and a varactor diode 5; the copper metasurface shape unit includes: a first copper vertical line 1, a second copper vertical line 2, a first copper horizontal line 3, and a second copper horizontal line 4; the first copper vertical line 1 and the second copper vertical line 2 are placed in parallel; the first copper horizontal line 3 is placed in the middle of the first copper vertical line 1, and the second copper horizontal line 4 is placed in the middle of the second copper vertical line 2; the first copper horizontal line 3 and the second copper horizontal line 4 are respectively placed perpendicular to the first copper vertical line 1; the first copper horizontal line 3 and the second copper horizontal line 4 are connected via the varactor diode 5;

[0043] The second copper layer 7 and the third copper layer 9 are connected by a switch to form a DC bias circuit.

[0044] In this embodiment, the switch array consists of four single-pole, double-throw (SPDT) switches, one for each of the four binary digits. Each SPDT switch is implemented using a field-effect transistor (FET). The gate of the FET serves as the control terminal, while the source and drain serve as the common and select terminals of the SPDT switch, respectively. By applying signals of varying voltage levels to the gate, the on and off states of the source and drain are controlled, achieving the switching function.

[0045] The positive terminal of the DC bias circuit power supply is connected to the third copper layer, while the second copper layer serves as the output terminal, connected to a varactor diode. By encoding and controlling the 4-bit binary switch array to change the switch's conduction state, voltage divider resistors of varying resistance are connected to the circuit. Different voltage divider resistor combinations produce varying voltage drops between the second and third copper layers, resulting in varying voltage outputs on the second copper layer. This voltage acts as the varactor diode's reverse bias voltage, adjusting its capacitance and ultimately achieving spatial phase control.

[0046] By combining a 4-bit binary switch array with a voltage divider resistor network, a 0-30V bias voltage is generated, and the capacitance of the varactor diode is precisely controlled to achieve continuous phase adjustment from 0 to 360 degrees. The switch array response time is <1μs, and combined with the fast capacitance stabilization characteristics of the varactor diode (4μs), it can meet dynamic stealth requirements. The offline three-dimensional deformation-phase mapping database, combined with real-time table lookup control, eliminates the need for external sensors and enables fast phase compensation. The target capacitance is directly calculated based on the capacitance-phase linear relationship of the varactor diode, simplifying the control logic.

[0047] The polyimide layer provides flexible support with a curvature radius R ≥ 15mm, while the copper pillar structure ensures reliable electrical connections despite deformation. The voltage divider network outputs a voltage fluctuation of ≤ ±0.1V, eliminating the need for an external power supply and reducing system power consumption by 70% compared to traditional solutions.

[0048] In this embodiment, a five-layer flexible stacked structure consisting of an H-shaped copper layer (including a varactor diode), a double polyimide layer, a metal reflective layer and a microstrip line layer achieves surface conformality and solves the problem of non-deformability of traditional rigid metasurfaces.

[0049] The flexible deformable metasurface unit is further provided with a first copper pillar 10 and a second copper pillar 11. The first copper pillar 10 sequentially penetrates the first polyimide layer 6, the second copper layer 7, and the second polyimide layer 8, and connects the first copper horizontal line 3 to the third copper layer 9.

[0050] The second copper pillar 11 penetrates the first polyimide layer 6 and connects the second copper horizontal line 4 to the second copper layer 7; the first copper pillar 10 and the second copper pillar 11 are respectively arranged on the left and right sides of the varactor diode 5; the first copper pillar 10 and the second copper layer 7 are insulated;

[0051] The metasurface unit constructs a closed-loop bias circuit through the first copper pillar 10 and the second copper pillar 11 .

[0052] The insulation distance between the first copper pillar 10 and the second copper layer 11 is 0.05 mm. The first copper pillar 10 and the second copper pillar 11 are respectively arranged on the left and right sides of the varactor diode 5, with a distance of 3 mm. The radius of the first copper pillar 10 and the second copper pillar 11 are both 0.15 mm.

[0053] In this embodiment, the insulation distance between the first copper pillar 10 and the second copper layer 11 is 0.05 mm, which avoids the risk of short circuit during deformation and ensures electrical stability.

[0054] The third copper layer is a strip-shaped microstrip line with a width of 0.8 mm.

[0055] In this embodiment, a microstrip integrated coupler extracts the reflected wave phase error in real time, optimizes the driving voltage through fast Fourier transform and adaptive threshold adjustment, and controls the wavefront distortion to <λ / 10 (the standard deviation of the phase error is 0.8° when R = 15mm), thereby improving the compensation robustness.

[0056] The size of the metasurface unit is 16×16 mm.

[0057] The thickness of the copper metasurface shape unit of the first copper layer is 0.035 mm; wherein, the total length and total width of the H-shape are both 10 mm, and the gap between the horizontal and vertical lines is both 1 mm.

[0058] The thickness of the first polyimide layer is 0.8 mm, the second copper layer is a metal reflective layer with a thickness of 0.1 mm, and the thickness of the second polyimide layer is 0.5 mm.

[0059] The resistance of the varactor diode is 2.5Ω, and the inductance is 0.7nH.

[0060] Example 2

[0061] The present invention also provides a method for dynamic phase compensation of a metasurface unit;

[0062] like Figure 4 As shown in (c), when the incident wave illuminates the flexible metasurface in parallel, each varactor diode on the flexible metasurface will reversely infer the corresponding phase difference based on the deformation caused by the object it covers, and then deduce the target capacitance and calculate the bias voltage, thereby achieving dynamic phase compensation and ensuring that the reflected wave is still emitted in parallel.

[0063] A deformation-phase mapping database must first be established. In the simulation software CST, the metasurface units are arranged in different arrays to obtain metasurfaces with different curvature radii. By simulating the reflection phase distribution of the metasurface at different curvature radii, a deformation-phase mapping database can be established.

[0064] Furthermore, it is necessary to measure the capacitance value of the varactor diode under 0-30V bias and fit the phase-capacitance relationship. That is, when the capacitance decreases by 1pf, the phase changes

[0065] Furthermore, when the flexible deformable metasurface unit receives an external deformation instruction, it queries the deformation-phase mapping database according to the deformation parameters to obtain the target phase At this time, the target phase The corresponding capacitance reduction is The target capacitance value is obtained as:

[0066]

[0067] Among them, C target is the target capacitance value, C0 is the maximum initial voltage of the varactor diode, that is, the capacitance value when the bias voltage is 0V;

[0068] The relationship between the capacitance of the varactor diode 5 and the reverse bias voltage V is:

[0069]

[0070] Where V is the reverse bias voltage, V j is the junction voltage, V j =0.7V; m is the gradient coefficient;

[0071] Substituting (1) into (2), taking m = 0.5, we can get the driving voltage V c :

[0072]

[0073] The beneficial effects of this embodiment are:

[0074] a. Sensorless dynamic phase compensation: Through a pre-stored deformation-phase mapping database and lookup table control, the external deformation sensor is eliminated and the target phase is directly queried based on the curvature radius and deformation direction. Combined with the voltage-capacitance characteristics of the varactor diode for real-time control, the system structure is simplified while ensuring phase compensation accuracy (phase error standard deviation ≤ 0.8°).

[0075] b. Ultra-wide phase control range and fast response: Utilizing the capacitance adjustment range of the varactor diode (corresponding to 0-360° phase coverage) and 5μs response speed (1μs for switch switching + 4μs for capacitor stabilization), dynamic deformation of the curvature radius R ≥ 15mm can be compensated in real time, meeting the strict requirements of flexible stealth for wavefront distortion <λ / 10.

[0076] c. Low-cost integrated design: A 4-bit binary switch array and a voltage-divider resistor network replace the traditional complex drive circuit, reducing the number of components by 60% and the cost by 70%. The control logic is simplified to table lookup-calculation-switch action, which is compatible with FPGAs or microcontrollers, facilitating large-scale integration and mass production.

[0077] d. Closed-loop self-correction capability: Phase error is extracted through microstrip line coupling reflected wave signals, and the driving voltage is optimized through adaptive threshold adjustment to further improve phase compensation stability (voltage fluctuation ≤ ±0.1V) and avoid deviations between the offline mapping table and actual application.

[0078] e. Flexible structural adaptability: The polyimide layer in the layered design provides mechanical flexibility (curvature radius R ≥ 15mm), and the copper pillars running through the structure ensure the reliability of electrical connections under deformation, making it suitable for complex scenarios such as curved invisible cloaks and wearable electronics.

[0079] Compared with the prior art, this embodiment also has the following technical effects:

[0080] 1) Existing technologies are difficult to adapt to dynamic scenarios such as curved cloaks and wearable electronics. The flexible structure and rapid response capabilities of the present invention enable it to conform to complex curved surfaces with a curvature radius R ≥ 15 mm, achieving continuous phase compensation under dynamic deformation.

[0081] 2) Transmission technology relies on real-time feedback from external sensors, resulting in complex algorithms and high power consumption. This invention uses table-lookup feedforward control and closed-loop correction, establishes a three-dimensional deformation-phase mapping database offline, generates the target phase through real-time table lookup, directly calculates the capacitance value through a formula, and uses a voltage divider resistor network to generate a 0-30V bias voltage. This eliminates the need for an external power supply and reduces power consumption by 70%.

[0082] 3) The present invention adopts a 5-layer cascaded flexible structure, provides mechanical flexibility through the polyimide layer, and combines the double copper column through-hole design to ensure the reliability of electrical connection under deformation. Compared with the existing technology, the number of components is reduced by 60%, avoiding external welding or sensor integration, and significantly reducing the complexity of the structure. At the same time, the present invention realizes continuous phase compensation and improves the response speed through varactor diodes and 4-bit binary switch arrays. Combined with closed-loop correction, the standard deviation of the phase error is only 0.8°, the wavefront distortion is controlled at <λ / 10 (traditionally about λ / 6), and the stealth accuracy is greatly improved.

[0083] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible deformable metasurface based on spatial dynamic phase compensation of varactor diodes, characterized in that: include: Flexible deformable metasurface unit; The flexible deformable metasurface unit is divided into five layers, which are, from top to bottom, a first copper layer, a first polyimide layer (6), a second copper layer (7), a second polyimide layer (8), and a third copper layer (9); The first copper layer comprises a copper super-surface shape unit and a varactor diode (5); the copper super-surface shape unit comprises: a first copper vertical line (1), a second copper vertical line (2), a first copper horizontal line (3) and a second copper horizontal line (4); The first copper vertical line (1) and the second copper vertical line (2) are placed in parallel; the first copper horizontal line (3) is placed in the middle of the first copper vertical line (1), and the second copper horizontal line (4) is placed in the middle of the second copper vertical line (2); the first copper horizontal line (3) and the second copper horizontal line (4) are respectively placed perpendicular to the first copper vertical line (1); the first copper horizontal line (3) and the second copper horizontal line (4) are connected via the varactor diode (5); The second copper layer (7) and the third copper layer (9) are connected by a switch array to form a DC bias circuit.

2. The flexible deformable metasurface based on spatial dynamic phase compensation of varactor diode according to claim 1, characterized in that: The flexible deformable metasurface unit is further provided with a first copper column (10) and a second copper column (11), wherein the first copper column (10) sequentially penetrates the first polyimide layer (6), the second copper layer (7), and the second polyimide layer (8), and connects the first copper horizontal line (3) to the third copper layer (9); The second copper pillar (11) penetrates the first polyimide layer (6) and connects the second copper horizontal line (4) and the second copper layer (7); the first copper pillar (10) and the second copper pillar (11) are respectively arranged on the left and right sides of the varactor diode (5); the first copper pillar (10) and the second copper layer (7) are insulated; The flexible deformable metasurface unit constructs a closed-loop bias circuit through the first copper column (10) and the second copper column (11).

3. The flexible deformable metasurface based on spatial dynamic phase compensation of varactor diode according to claim 2, characterized in that: The insulation distance between the first copper pillar (10) and the second copper layer (7) is 0.05 mm; the first copper pillar (10) and the second copper pillar (11) are respectively arranged on the left and right sides of the varactor diode (5), the distance between the first copper pillar (10) and the second copper pillar (11) is 3 mm, and the radius of the first copper pillar (10) and the second copper pillar (11) are both 0.15 mm.

4. The flexible deformable metasurface based on spatial dynamic phase compensation of varactor diode according to claim 1, characterized in that: The switch array is composed of four single-pole double-throw switches, each of which is implemented by a field-effect transistor. The gate of the field-effect transistor serves as the control terminal, and the source and drain serve as the common terminal and selection terminal of the single-pole double-throw switch respectively; by applying different level signals to the gate, the on and off states of the source and drain are controlled to realize the switching function.

5. The flexible deformable metasurface based on spatial dynamic phase compensation of varactor diode according to claim 1, characterized in that: The third copper layer (9) is a strip-shaped microstrip line with a width of 0.8 mm.

6. The flexible deformable metasurface based on spatial dynamic phase compensation of varactor diode according to claim 1, characterized in that: The size of the flexible deformable metasurface unit is 16×16 mm.

7. The flexible metasurface based on spatial dynamic phase compensation of varactor diode according to claim 1, characterized in that: The thickness of the copper supersurface shape unit of the first copper layer is 0.035 mm; the total length and total width of the first copper layer are both 10 mm; the gap between the first copper vertical line (1) and the first copper horizontal line (3) is 1 mm; and the gap between the second copper vertical line (2) and the second copper horizontal line (4) is 1 mm.

8. The flexible metasurface based on spatial dynamic phase compensation of varactor diodes according to claim 1 is characterized in that: The thickness of the first polyimide layer (6) is 0.8 mm, the second copper layer (7) is a metal reflective layer with a thickness of 0.1 mm; and the thickness of the second polyimide layer (8) is 0.5 mm.

9. The flexible metasurface based on spatial dynamic phase compensation of varactor diode according to claim 1, characterized in that: The resistance of the varactor diode (5) is 2.5Ω, and the inductance is 0.7nH.

10. The flexible metasurface based on spatial dynamic phase compensation of varactor diode according to claim 1, characterized in that: When the flexible deformable metasurface unit receives an external deformation instruction, it queries the deformation-phase mapping database according to the deformation parameters to obtain the target phase The target phase The corresponding capacitance reduction is The target capacitance value is obtained as: Among them, C target is the target capacitance value, C0 is the maximum initial voltage of the varactor diode, that is, the capacitance value when the bias voltage is 0V; The relationship between the capacitance of the varactor diode (5) and the reverse bias voltage V is: Among them, C j0 (V) is the relationship between capacitance and reverse bias voltage V, V is the reverse bias voltage, V j is the junction voltage, V j =0.7V; m is the gradient coefficient; Substituting (1) into (2), taking m = 0.5, we can get the driving voltage V c :

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