High-linearity microwave plane angular displacement sensor based on dual-mode gradient ring resonator

Abstract

The invention belongs to the technical field of microwave sensor manufacturing, and particularly relates to a high-linearity microwave plane angular displacement sensor based on a dual-mode gradient ring resonator. The high-linearity microwave plane angular displacement sensor based on the dual-mode gradient ring resonator comprises a stator and a rotor arranged on the stator. The upper surface of the stator is provided with a metal gradient annular resonant structure and a T-shaped metal feed microstrip line; the outer end of the T-shaped metal feed microstrip line is connected with an input / output port; the lower surface of the stator is provided with a metal ground plane; a metal wire is arranged on the lower surface of the rotor; the lower surface of the rotor is attached to the upper surface of the stator to form electric contact. The method has the characteristics that the response linearity of the sensor can be remarkably improved, and relatively high sensitivity and relatively high measurement range are realized at the same time.

Description

Technical Field

[0001] This invention belongs to the field of microwave sensor manufacturing technology, specifically relating to a high linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator. Background Technology

[0002] Compared to sensors operating at lower frequencies or based on other principles, microwave resonant sensors offer advantages such as relatively lower cost, smaller size, higher sensitivity, and higher integration. Therefore, microwave sensors are finding increasingly widespread applications in materials characterization, biomedical sensing, chemical detection, and displacement sensing.

[0003] Precise angular displacement measurement is crucial for controlling various machines, including attitude control or torque measurement in spacecraft reaction wheels and robot-assisted surgery. Microwave resonant angular displacement sensors typically consist of a stator fixed to a test platform and a rotor rotating on it; the resonator response (such as resonant frequency and amplitude) changes with the rotation angle. For angular displacement sensors, key performance indicators include measurement range, sensitivity, and linearity. Measurement range determines the sensor's applicable scenarios and fields, sensitivity determines the sensor's detection of minute angular changes, and linearity determines the complexity of the sensor signal processing circuitry and the accuracy of detecting continuous angular changes. However, among the many angular displacement sensors, while the measurement range can be adjusted and selected according to the working environment, sensitivity and linearity often cannot simultaneously achieve satisfactory levels; often, improving one performance indicator leads to a decrease in the other. In existing microwave angular displacement sensors, high-sensitivity sensors tend to have lower response linearity, often exhibiting poor linearity or quadratic linearity, while high-linearity sensors often sacrifice sensitivity to achieve improved linearity.

[0004] Therefore, it is essential to design a high-linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator that can significantly improve the linearity of the sensor response while achieving high sensitivity and measurement range. Summary of the Invention

[0005] The present invention aims to overcome the problem of poor linearity in existing microwave angular displacement sensors by providing a high-linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator, which can significantly improve the linearity of the sensor response while achieving high sensitivity and measurement range.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] A high-linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator includes a stator and a rotor mounted on the stator. The upper surface of the stator is provided with a metal gradient ring resonator structure and a T-shaped metal-fed microstrip line. The outer end of the T-shaped metal-fed microstrip line is connected to an input / output port. The lower surface of the stator is provided with a metal ground plane. The lower surface of the rotor is provided with a metal wire. The lower surface of the rotor is in contact with the upper surface of the stator to form an electrical contact.

[0008] Preferably, both the stator and rotor are made of dielectric material.

[0009] Preferably, the main body of the stator is in the shape of a square thin plate; the center of the stator is provided with a through hole for connecting and fixing the rotor and the stator.

[0010] Preferably, the metal gradient ring resonant structure is obtained by performing a Boolean subtraction operation on two non-concentric circles whose centers are located on the vertical axis, cutting them into two parts according to the axis, and then performing a vertical flipping operation on the right half; wherein, the outer circle of the non-concentric circle used for Boolean subtraction shares the same center with the through hole on the stator center.

[0011] Preferably, the main body of the rotor is a thin plate composed of an outer fan shape and an inner annular shape; the inner annular thin plate of the rotor has a through hole at its center for connecting and fixing the rotor and the stator; the through hole at the center of the inner annular thin plate of the rotor corresponds to the through hole at the center of the stator.

[0012] Preferably, the metal wires on the lower surface of the rotor extend from the outer fan-shaped edge to the inner annular portion.

[0013] Preferably, the initial 0° position is set at the junction of the narrow and wide segments of the metal gradient ring resonant structure on the upper surface of the stator away from the T-type feed microstrip line, with the vertical line as the dividing line, and the final position is 120° counterclockwise. During the rotation of the rotor, the upper surface of the stator and the lower surface of the rotor are in close contact, and the metal line on the lower surface of the rotor is used as the pointing line to rotate from the initial 0° position to the final position.

[0014] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention can significantly improve the linearity of the sensor response, while achieving higher sensitivity and measurement range. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural schematic diagram of a high linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator according to the present invention.

[0016] Figure 2 This is a schematic diagram of one structure of the stator in this invention;

[0017] Figure 3This is a schematic diagram of one structure of the rotor in this invention;

[0018] Figure 4 This is a schematic diagram of the simulation results of a high linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator according to the present invention.

[0019] Figure 5 This is a schematic diagram illustrating the change of resonant frequency difference as an angle in the high linearity microwave planar angular displacement sensor based on a dual-mode gradually changing ring resonator according to the present invention.

[0020] Figure 6 This is a schematic diagram of a linear fitting result for the resonant frequency difference of a high-linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator, according to the present invention.

[0021] In the figure: Stator 1, Stator through-hole structure 1-1, Metal gradient ring resonant structure 1-2, T-type metal-fed microstrip line 1-3, Metal ground plane 1-4, Rotor 2, Rotor through-hole structure 2-1, Metal wire 2-2. Detailed Implementation

[0022] To more clearly illustrate the embodiments of the present invention, specific implementation methods will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0023] Example:

[0024] like Figure 1 As shown, the present invention provides a high linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator, including a stator 1 and a rotor 2 disposed on the stator; the upper surface of the stator is provided with a metal gradient ring resonator structure 1-2 and a T-shaped metal-fed microstrip line 1-3; the outer end of the T-shaped metal-fed microstrip line is connected to an input / output port; the lower surface of the stator is provided with a metal ground plane; the lower surface of the rotor is provided with a metal line 2-2; the lower surface of the rotor is attached to the upper surface of the stator to form an electrical contact.

[0025] The present invention is a high linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator. It is a single-port device with the characteristics of high linearity and high sensitivity.

[0026] Furthermore, both the stator and rotor are made of dielectric materials. Specifically, the stator's dielectric substrate is made of Rogers 4350 with a thickness of 0.762 mm; the rotor's dielectric substrate is also made of Rogers 4350 with a thickness of 1.524 mm.

[0027] like Figure 2As shown, the main body of the stator is a square thin plate made of dielectric material. The square thin plate has a stator through hole structure 1-1 in the center, which is used to fix the rotor and the stator.

[0028] The gradient ring resonant structure on the upper surface of the stator is obtained by performing a Boolean subtraction operation on two non-concentric circles with their centers on the vertical axis, then cutting it into two parts according to the axis, and finally performing a vertical flipping operation on the right half. The outer circle of the non-concentric circle used for the Boolean subtraction shares a common center with the through hole. For example... Figure 2 As shown, the stator parameters are (all in millimeters): w b =34, l b =34, w0=1.5, w1=1.5, l0=9.25, R i =5,R o =6,R f =7.75, R h =1.5, d c =0.8, α1=90°.

[0029] like Figure 3 As shown, the rotor's main body is a thin plate made of dielectric material, consisting of an outer fan-shaped section and an inner annular section. A rotor through-hole structure 2-1 is opened at the center of the inner annular plate to secure the rotor and stator. The rotor through-hole structure corresponds in position to the stator through-hole structure. Metal wires on the lower surface of the rotor extend from the edge of the outer fan-shaped section to the inner annular section. For example... Figure 3 As shown, the rotor's parameters are (all in millimeters): R t =3, w t =0.5, l t =4, R o =6,R h =1.5, α2 = 30°.

[0030] As the rotor rotates, the equivalent electrical dimensions of the metal gradient ring resonant structure change, causing a linear change in the resonant frequency, achieving good linearity and high sensitivity within the range of 0°–120°. The initial 0° position is defined by the boundary between the narrow and wide segments of the metal gradient ring resonant structure on the stator's upper surface, away from the metal T-shaped feed microstrip line, using a vertical line as a dividing line. The final position is 120° counterclockwise. During rotation, the upper surface of the stator and the lower surface of the rotor are in close contact, with the metal wire on the lower surface of the rotor serving as a guiding line, rotating from the aforementioned initial position to the final position.

[0031] The specific method for measuring the angle position in this embodiment is as follows:

[0032] like Figure 1As shown, the upper surface of the stator and the lower surface of the rotor are tightly fitted together to form a stable electrical connection, ensuring that the outer edge of the rotor's sector coincides with the outer edge of the metal graded ring resonant structure. In implementation, the stator's port input wave signal excites the metal graded ring resonant structure through a metal T-type fed microstrip line, causing it to resonate at two specific frequencies. The return loss S is determined according to the parameter. 11 The specific resonant frequency can be obtained from the dB value. During the rotor rotation, the equivalent electrical dimensions of the resonant unit (metal graded ring resonant structure) change, which in turn causes changes in the two resonant frequency points.

[0033] like Figure 4 As shown, the return loss S of the sensor under different rotation angles is obtained from simulations in the 3D electromagnetic simulation software Ansys HFSS. 11 The graph shows the variation in dB. Within the range of 0°–30°, the rotor metal wire causes significant disturbance to the narrow segment of the resonant ring where the electric field converges, and the two resonant frequency points are close to each other. Within this measurement range, the sensor sensitivity is high. Within the range of 30°–120°, the influence of the rotor metal wire on the narrow and wide ends of the resonant ring where the electric field converges is relatively average. Furthermore, the changes in the width of the resonant ring caused by the rotation angle and the changes in the disturbance of the open-circuit stub work together on the change in the resonant frequency point, thereby improving the linearity of the sensor response. At the same time, the two resonant frequency points are further apart, which compensates for the decrease in sensitivity caused by the improvement in linearity.

[0034] like Figure 5 The figure shows the variation of the resonant frequency difference of the microwave angular displacement sensor with angle, obtained from simulation in the three-dimensional electromagnetic simulation software Ansys HFSS. According to the simulation results, the resonant frequency points of the angular displacement sensor proposed in this invention are closer to each other in the range of 0°–30° and farther apart in the range of 30°–120°, achieving a high sensitivity of 12.58MHz / ° in the range of 0–120°.

[0035] like Figure 6 The figure shows the linear fitting result of the resonant frequency difference of the simulated microwave angular displacement sensor. Using the least squares method, a linear fit was performed on the resonant frequency difference of the sensor response. The resonant frequency difference and the rotation angle within the range of 30°–120° satisfy a linear relationship:

[0036] Δf = 0.01068 * θ + 0.825284

[0037] Where Δf is the difference between the two resonant frequencies, θ is the angle of rotation, and R represents this linear relationship. 2 The mean square error (MSE) is 0.9764, and the mean square error (MSE) is 0.0022 GHz, which demonstrates the high linearity of the sensor response designed in this invention.

[0038] The high linearity microwave planar angular displacement sensor design based on a dual-mode gradient ring resonator proposed in this invention can significantly improve the linearity of the sensor response, while achieving high sensitivity and measurement range.

[0039] The above description is merely a detailed explanation of preferred embodiments and principles of the present invention. For those skilled in the art, there may be changes in specific implementation methods based on the ideas provided by the present invention, and these changes should also be considered within the scope of protection of the present invention.

Claims

1. A high-linearity microwave planar angular displacement sensor based on a dual-mode graded ring resonator, characterized in that, It includes a stator and a rotor mounted on the stator; the upper surface of the stator is provided with a metal gradient ring resonant structure and a T-shaped metal-fed microstrip line; the outer end of the T-shaped metal-fed microstrip line is connected to the input and output ports; the lower surface of the stator is provided with a metal ground plane; the lower surface of the rotor is provided with a metal wire; the lower surface of the rotor is in contact with the upper surface of the stator to form an electrical contact.

2. The high linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator according to claim 1, characterized in that, Both the stator and rotor are made of dielectric material.

3. The high linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator according to claim 2, characterized in that, The main body of the stator is in the shape of a square thin plate; the center of the stator is provided with a through hole for connecting and fixing the rotor and the stator.

4. The high linearity microwave planar angular displacement sensor based on a dual-mode graded ring resonator according to claim 3, characterized in that, The metal gradient ring resonant structure is obtained by performing a Boolean subtraction operation on two non-concentric circles whose centers are located on the vertical axis, cutting them into two parts according to the axis, and then performing a vertical flipping operation on the right half; wherein, the outer circle of the non-concentric circle used for Boolean subtraction shares the same center with the through hole on the center of the stator.

5. The high linearity microwave planar angular displacement sensor based on a dual-mode graded ring resonator according to claim 4, characterized in that, The main body of the rotor is a thin plate composed of an outer fan shape and an inner ring shape; the inner ring plate of the rotor has a through hole at its center for connecting and fixing the rotor and the stator; the through hole at the center of the inner ring plate of the rotor corresponds to the through hole at the center of the stator.

6. The high linearity microwave planar angular displacement sensor based on a dual-mode graded ring resonator according to claim 5, characterized in that, The metal wires on the lower surface of the rotor extend from the outer fan-shaped edge to the inner annular portion.

7. The high linearity microwave planar angular displacement sensor based on a dual-mode gradient ring resonator according to claim 1, characterized in that, The initial 0° position is defined by the vertical line as the dividing line, and the junction of the narrow and wide segments of the metal gradient ring resonant structure on the upper surface of the stator away from the T-type feed microstrip line is defined as the initial 0° position, and the final position is 120° counterclockwise. During the rotation of the rotor, the upper surface of the stator and the lower surface of the rotor are in close contact, and the metal line on the lower surface of the rotor is used as the pointing line to rotate from the initial 0° position to the final position.

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