Improved structure of electric field sensor and method for ensuring accuracy of electric field signal

Abstract

The invention provides an improved structure of an electric field sensor and a method for ensuring the accuracy of an electric field signal, and the structure is characterized in that an electric field sensitive chip is fixed in a packaging housing, and is connected with a control circuit; the electric field sensitive chip comprises at least one electrode assembly, the electrode assembly is composed of at least one dynamic electrode and at least one static electrode, the dynamic electrode is driven by an initial driving signal to vibrate in a reciprocating mode, and when the dynamic electrode and the static electrode are located in different planes, the static electrode is driven to vibrate. The static electrode generates and outputs a current sensing signal for determining the vibration state of the dynamic electrode; and the control circuit receives and analyzes the input current sensing signal to obtain a next driving signal for ensuring that the dynamic electrode can stably vibrate. By additionally arranging the static electrode, the current induction signal corresponding to the vibration state of the dynamic electrode can be obtained, and after the current induction signal is analyzed, it can be ensured that the dynamic electrode can output an accurate electric field signal.

Description

Technical Field

[0001] This invention relates to the field of electric field sensors, and in particular to an improved structure of an electric field sensor and a method for ensuring the accuracy of electric field signals. Background Technology

[0002] In existing MEMS piezoelectric field sensors, the state of an elastic beam is typically detected using an amplitude detection control structure. This structure comprises two parallel piezoelectric layers deposited on the elastic beam: a first piezoelectric layer and a second piezoelectric layer. The first piezoelectric layer utilizes the inverse piezoelectric effect to convert the driving electrical signal into deformation, driving the elastic beam to vibrate. The second piezoelectric layer utilizes the direct piezoelectric effect to convert the deformation signal of the elastic beam into an electrical signal output, thereby detecting the state of the elastic beam in real time and determining the motion state of the sensing electrode based on the obtained elastic beam state. However, this amplitude detection control structure has the following problems: 1. The parallel deposition design of the first and second piezoelectric layers creates a capacitor structure between them, which is equivalent to adding a feedthrough capacitor to the sensor's equivalent circuit, inevitably affecting the accuracy of the sensor's output signal. 2. The piezoelectric material may undergo performance changes when exposed to external environmental influences. This phenomenon can occur simultaneously in both the driving and detection piezoelectric layers, preventing the detection piezoelectric layer from correctly detecting changes in the elastic beam.

[0003] Based on the above, how to ensure that the dynamic electrode can output an accurate electric field signal without using an amplitude detection and control structure is a problem that urgently needs to be solved. Summary of the Invention

[0004] To address the shortcomings mentioned above, this invention provides an improved structure for an electric field sensor that can obtain a current sensing signal corresponding to the vibration state of a dynamic electrode without employing an amplitude detection and control structure, and can ensure that the dynamic electrode can output an accurate electric field signal after analyzing the current sensing signal, as well as a method for ensuring the accuracy of the electric field signal.

[0005] To achieve the above objectives, in a first aspect, the present invention provides an improved structure for an electric field sensor, comprising a package housing, an electric field sensing chip, and a control circuit, wherein the electric field sensing chip is fixed inside the package housing and connected to the control circuit; The electric field sensitive chip includes at least one electrode assembly, which consists of at least one dynamic electrode and at least one static electrode. The dynamic electrode reciprocates under the drive of an initial driving signal. When the dynamic electrode and the static electrode are in different planes, the static electrode generates and outputs a current sensing signal to determine the vibration state of the dynamic electrode. The control circuit receives and analyzes the input current sensing signal to derive the next driving signal that ensures the dynamic electrode can vibrate stably, so that the dynamic electrode outputs an accurate electric field signal under the action of the next driving signal.

[0006] In one embodiment, the control circuit is located outside the package housing and includes a phase difference detection module, a comparison module, a loop filter, and an NCO voltage-controlled oscillator, wherein: The phase difference detection module is connected to the static electrode and is used to receive the current sensing signal input by the static electrode and to obtain the current phase difference based on the current sensing signal and the preset sensing signal. The comparison module is used to compare whether the current phase difference is the same as the set phase difference; The loop filter is used to set the P value and I value according to the current phase difference in order to output a tuning voltage; The NCO voltage-controlled oscillator is connected to the dynamic electrode. The NCO voltage-controlled oscillator inputs the next drive signal derived from the tuning voltage into the dynamic electrode to ensure that the dynamic electrode outputs an accurate electric field signal under the action of the next drive signal.

[0007] In one embodiment, the electric field-sensitive chip further includes a substrate, wherein: The substrate provides a carrier for the dynamic electrode and the static electrode, and includes a solid region and a recessed region. The dynamic electrode includes a non-vibrating portion attached to the solid region and a vibrating portion attached above the recessed region. The vibrating portion generates an electrical signal when it reciprocates. The static electrode includes a first portion attached to the solid region and a second portion attached above the recessed region, wherein the second portion is adjacent to at least a portion of the vibrating portion, and when the second portion and the vibrating portion are on different planes, the current sensing signal is generated for determining the vibration state of the dynamic electrode.

[0008] In one embodiment, the static electrode includes an elastic beam a, a detection electrode, and a feedback electrode, wherein: The elastic beam a includes a first part a attached to the solid region and a second part a attached above the recessed region; The detection electrode is attached to at least a portion of the top end face of the second part a; The feedback electrode is attached to the top end face of the first part a and connected to the detection electrode, receiving and outputting the sensing signal obtained by the detection electrode.

[0009] In one embodiment, the dynamic electrode includes an elastic beam b, a piezoelectric electrode, a sensing electrode, and a lead-out electrode, wherein: The elastic beam b includes a first part b attached to the solid region and a second part b attached above the recessed region; The sensing electrode is attached to the top end face of the second part a and adjacent to at least a portion of the detection electrode, wherein the sensing electrode generates an electrical signal during reciprocating vibration; A portion of the piezoelectric electrode is attached to the top end face of the second part a and is located behind the sensing electrode. Another portion of the piezoelectric electrode is attached to the top end face of the second part b. The piezoelectric electrode deforms under the drive of an initial driving signal or a next driving signal. The lead-out electrode is attached to the top end face of the second part b, wherein the lead-out electrode is used to receive the electrical signal input by the sensing electrode and to input the initial drive signal or the next drive signal to the piezoelectric electrode.

[0010] In one embodiment, the static electrode includes a first static electrode and a second static electrode. The first static electrode includes a first elastic beam, a first detection electrode, and a first feedback electrode. The second static electrode includes a second elastic beam, a second detection electrode, and a second feedback electrode. The first detection electrode and the second detection electrode are both adjacent to the sensing electrode. When the sensing electrode is on a different plane from the first detection electrode and the second detection electrode, a first sensing signal and a second sensing signal are generated to determine the vibration state of the sensing electrode.

[0011] In one embodiment, the position of the first detection electrode corresponds to the position of the second detection electrode, or the position of the first detection electrode is adjacent to the position of the second detection electrode.

[0012] In one embodiment, the package housing includes a package cover plate and a package tube shell, wherein the package cover plate is fixed to the top end face of the package tube shell by Kovar solder rings to form the package structure of the electric field sensitive chip; An adhesive area for fixing the electric field sensitive chip is formed on the inner end face of the package shell, and the package shell is also provided with a plurality of solder points that are respectively connected to the electric field sensitive chip and the control circuit.

[0013] In one embodiment, a downwardly extending region is formed on the end face of the encapsulation cover facing the encapsulation housing.

[0014] Secondly, the present invention also provides a method for ensuring the accuracy of the electric field output signal, applied to the improved structure of the above-mentioned electric field sensor, comprising the following steps: The static electrode senses the vibration state of the dynamic electrode to output a current sensing signal corresponding to the vibration state; Determine whether the current phase difference between the current sensing signal and the preset sensing signal is the same as the set phase difference. If yes, receive the next sensing signal input by the static electrode. If no, set the P value and I value according to the current phase difference to output the tuning voltage. The next driving signal, based on the tuning voltage output, enables the dynamic electrode to vibrate stably, thereby ensuring that the dynamic electrode outputs an accurate electric field signal under the action of the next driving signal.

[0015] Compared with the prior art, the present invention has one of the following advantages: By adding a static electrode, the current induced signal corresponding to the vibration state of the dynamic electrode can be obtained without using an amplitude detection and control structure. After analyzing the current induced signal, it can be ensured that the dynamic electrode can output an accurate electric field signal. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the first embodiment of the electric field sensor in this invention; Figure 2 This is a cross-sectional view of the second embodiment of the electric field sensor in this invention; Figure 3 for Figure 1 or Figure 2 Block diagram of the electric field sensor; Figure 4 for Figure 3 Top view of the first embodiment of the electric field sensitive chip; Figure 5 for Figure 3 Top view of a second embodiment of a medium electric field sensitive chip; Figure 6 for Figure 5 A three-dimensional image; Figure 7 for Figure 3 A top view of the third embodiment of the electric field sensitive chip; Figure 8 for Figure 3 A top view of the fourth embodiment of the electric field sensitive chip; Figure 9 for Figure 8 A three-dimensional image; Figure 10 This is a flowchart of the method for ensuring accurate electric field output signal in this invention.

[0017] The main reference numerals are as follows: 1-Substrate; 100-Solid region; 101-Recessed region; 2-Static electrode; 200-Elastic beam a; 2000-First part a; 2001-Second part a; 201-Detection electrode; 202-Feedback electrode; 3-Dynamic electrode; 300-Elastic beam b; 3000-First part b; 3001-Second part b; 301-Induction electrode; 3010-Comb structure; 302-Piezoelectric electrode; 3020-Piezoelectric layer; 3021-Lower piezoelectric electrode; 3022-Upper piezoelectric electrode; 303-Lead electrode; 4-First static electrode; 400-First elastic beam; 401-First detection electrode; 4010-First comb structure; 402-First feedback electrode; 5-Second static electrode; 500-Second elastic beam; 501-Second detection electrode; 5010-Second comb structure; 502-Second feedback electrode; 6-Control circuit; 601-Phase difference detection module; 602-Comparison module; 603-Loop filter; 604-NCO voltage-controlled oscillator; 7-Package cover; 701-Lower extension area; 8-Package housing; 9-Electric field sensitive chip; 10-Adhesive area; 11-Solder joint; 12-Kovar solder ring. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0019] In the description of this invention, it should be understood that the terms "upper," "lower," "top surface," "bottom surface," and "inner," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention 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 the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Example

[0020] like Figure 1As shown, this embodiment provides an improved structure for an electric field sensor, including a package housing, an electric field sensing chip 9, and a control circuit 6. The electric field sensing chip 9 is fixed inside the package housing and connected to the control circuit 6.

[0021] Specifically, the package housing includes a package cover plate 7 and a package tube shell 8. The electric field sensitive chip 9 includes a substrate and an electrode assembly. The electrode assembly consists of a dynamic electrode and a static electrode. A portion of the dynamic electrode and a portion of the static electrode are fixed on the substrate, and a portion of the static electrode is adjacent to a portion of the dynamic electrode. The dynamic electrode reciprocates under the drive signal. When the dynamic electrode and the static electrode are on different planes, the static electrode generates a current sensing signal. The package cover plate 7 is fixed to the top end face of the package tube shell 8 by Kovar solder rings 12, so that the package cover plate 7 and the package tube shell 8 form the package structure of the electric field sensitive chip 9, providing space for fixing the electric field sensitive chip 9. Among them, an adhesive area 10 for fixing the electric field sensitive chip 9 is formed on the inner end face of the bottom end of the package tube shell 8, and multiple solder points 11 are also provided on the bottom end of the package tube shell 8, which are respectively connected to the electric field sensitive chip 9 and the control circuit 6. The control circuit 6 is fixed on the bottom end face of the package 8 and connected to the electric field sensitive chip 9 through a designated solder point 11 to receive the electric field signal input from the electric field sensitive chip 9, the current sensing signal generated by the static electrode, or input the drive signal to the electric field sensitive chip 9 to drive the dynamic electrode to vibrate.

[0022] The control circuit 6 receives and analyzes the input current sensing signal to derive the next driving signal that ensures the dynamic electrode can vibrate stably, so that the dynamic electrode outputs an accurate electric field signal under the action of the next driving signal.

[0023] Furthermore, after the bottom end face of the substrate is fixed on the adhesive area 10, the dynamic electrode and the static electrode are positioned facing the encapsulation cover plate 7.

[0024] Furthermore, a lower extension region 701 is formed on the end face of the encapsulation cover 7 facing the encapsulation housing. By providing the lower extension region 701, it is easier to position the encapsulation cover 7 and the encapsulation housing 8 during assembly, thereby improving assembly efficiency. Example

[0025] like Figure 2 As shown, this embodiment provides an improved structure for an electric field sensor. The difference between this embodiment and Embodiment 1 is that: A groove is formed on the bottom end face of the package 8. After the control circuit 6 is embedded inside the groove, it is connected to the electric field sensitive chip 9 through the designated solder point 11.

[0026] The control circuit 6 is placed inside the groove, which can protect the control circuit 6 and prevent it from being damaged. Example

[0027] like Figure 3 As shown, in this embodiment, the dynamic electrode includes a sensing electrode 301, a piezoelectric electrode 302, and a lead-out electrode 303, while the static electrode includes a detection electrode 201 and a feedback plate 202. The detection electrode 201 is located adjacent to the sensing electrode. When the sensing electrode 301 vibrates, the sensing electrode 301 and the detection electrode 201 are on different planes. The detection electrode 201 generates a current sensing signal and outputs it through the feedback electrode 202 to determine the vibration state of the sensing electrode 301.

[0028] Specifically, the control circuit 6 receives and analyzes the current sensing signal input by the feedback electrode 202 to obtain the next driving signal that ensures the sensing electrode 301 can vibrate stably, so that the sensing electrode 301 outputs an accurate electric field signal under the action of the next driving signal.

[0029] Furthermore, the control circuit 6 includes a phase difference detection module 601, a comparison module 602, a loop filter 603, and an NCO voltage-controlled oscillator 604, wherein: The phase difference detection module 601 is connected to the feedback electrode 202 and is used to receive the current sensing signal input by the feedback electrode 202 and to obtain the current phase difference based on the current sensing signal and the preset sensing signal. The comparison module 602 is used to compare whether the current phase difference is the same as the set phase difference; The loop filter 603 is used to set the P and I values ​​according to the current phase difference to output a tuned voltage; The NCO voltage-controlled oscillator 604 is connected to the lead-out electrode 303. The NCO voltage-controlled oscillator 604 inputs the next drive signal obtained from the tuning voltage to the lead-out electrode 303 to ensure that the sensing electrode outputs an accurate electric field signal under the action of the next drive signal.

[0030] Example 4 like Figure 4As shown, this embodiment can be used in any of the electric field sensors described in Embodiments 1 to 3 above, including a substrate 1, a dynamic electrode 3, and a static electrode 2. The substrate 1 provides a carrier for the dynamic electrode 3 and the static electrode 2, and includes a solid region 100 and a recessed region 101. The static electrode 2 includes a first portion attached to the solid region 100 and a second portion attached above the recessed region 101, wherein the second portion is adjacent to the vibrating portion. When the second portion and the vibrating portion are on different planes, a sensing signal is generated to determine the vibration state of the dynamic electrode 3. The dynamic electrode 3 includes a non-vibrating portion attached to the solid region 100 and a vibrating portion attached above the recessed region 101. The vibrating portion generates an electrical signal when it reciprocates.

[0031] In this embodiment, the static electrode 2 and the dynamic electrode 3 are arranged in parallel, wherein the first part of the static electrode 2 and the non-vibration part of the dynamic electrode 3 are attached to the same side of the solid region 100.

[0032] Specifically, in the substrate 1, the recessed region 101 is formed by recessing a local area of ​​the top end face of the substrate 1 toward the bottom end face, and the solid region 100 surrounds the outside of the recessed region 101 to form a frame structure.

[0033] Preferably, the shape of the substrate 1, the shape of the recessed region 101, and the shape of the solid region 100 are all square structures.

[0034] Furthermore, the physical region 100 is composed of an insulating layer and a substrate layer stacked on top of each other. The insulating layer is used to isolate signals, and the material of the insulating layer is not limited to silicon dioxide, silicon nitride, or composite materials made of silicon dioxide and silicon nitride. The substrate layer can be made of silicon-based materials, glass, ceramics, organic materials, or metals and metal alloys.

[0035] Specifically, the static electrode 2 includes an elastic beam a200, a detection electrode 201, and a feedback electrode 202, wherein: The elastic beam a200 includes a first part a2000 attached to the solid region 100 and a second part a2001 located above the recessed region 101. The detection electrode 201 is attached to at least a portion of the top end face of the second part a2001. The feedback electrode 202 is attached to the top end face of the first part a2000 and connected to the detection electrode 201, receiving and outputting the sensing signal obtained by the detection electrode 201.

[0036] Furthermore, the second part a2001 includes a first region away from the physical region 100 and a second region adjacent to the physical region 100, wherein the width of the first region is greater than the width of the second region. The detection electrode 201 is attached to the entire area of ​​the first region, which can increase the sensitivity when sensing signals.

[0037] Optionally, the detection electrode 201 is connected to the feedback electrode 202 via a transmission line attached to the top end face of the elastic beam a200, or via a transmission line embedded inside the elastic beam a200, or the elastic beam a200 is made of a conductive material, and the detection electrode 201 is connected to the feedback electrode 202 via the conductive elastic beam a200.

[0038] Preferably, the detection electrode 201 is connected to the feedback electrode 202 through a transmission line embedded inside the elastic beam a200. This design can avoid damage to the transmission line and ensure that the signal can be transmitted effectively.

[0039] In this embodiment, preferably, the shape of the detection electrode 201 and the shape of the first region are both square structures.

[0040] Specifically, the dynamic electrode 3 includes an elastic beam b300, a piezoelectric electrode 302, a sensing electrode 301, and an output electrode 303.

[0041] The elastic beam b300 includes a first part b3000 attached to the solid region 100 and a second part b3001 located above the recessed region 101. The sensing electrode 301 generates an electrical signal when it reciprocates, wherein the sensing electrode 301 is attached to the top end face of the second part b3001 and adjacent to the detection electrode 201. The piezoelectric electrode 302 deforms under the influence of an initial drive signal or a next drive signal, wherein a portion of the piezoelectric electrode 302 is attached to the top end face of the second part b2001 and located behind the sensing electrode 301, and another portion of the piezoelectric electrode 302 is attached to the top end face of the second part b3001. The lead-out electrode 303 is used to receive the electrical signal input from the sensing electrode 301 and to input the initial drive signal or the next drive signal to the piezoelectric electrode 302, wherein the lead-out electrode 303 is attached to the top end face of the second part b3001.

[0042] Furthermore, the second part b3001 includes a first region away from the physical region 100 and a second region adjacent to the physical region 100, wherein the width of the first region is greater than the width of the second region. The sensing electrode 301 is attached to the entire area of ​​the first region, which can increase the sensitivity when sensing electric field signals.

[0043] Furthermore, the piezoelectric electrode 302 includes a piezoelectric layer 3020, an upper piezoelectric electrode 3022, and a lower piezoelectric electrode 3021. A first portion of the piezoelectric layer 3020 is attached to the second region, and a second portion of the piezoelectric layer 3020 is attached to the solid region 100. Both the upper piezoelectric electrode 3022 and the lower piezoelectric electrode 3021 are attached to the second portion.

[0044] Furthermore, a recessed position is formed in the second part of the piezoelectric layer 3020, and the piezoelectric lower electrode 3021 is attached to the recessed position, such that the position of the piezoelectric lower electrode 3021 and the position of the piezoelectric upper electrode 3022 are on different planes.

[0045] Optionally, the sensing electrode 301 and the piezoelectric electrode 302 are connected to the lead electrode 303 via a transmission line attached to the top end face of the elastic beam b300, or via a transmission line embedded inside the elastic beam b300, or the elastic beam b300 is made of a conductive material, and the detection electrode 201 is connected to the lead electrode 303 via the conductive elastic beam b300.

[0046] Preferably, the sensing electrode 301 and the piezoelectric electrode 302 are connected to the lead electrode 303 through a transmission line embedded inside the elastic beam b300. This design can avoid damage to the transmission line and ensure that the signal can be transmitted effectively.

[0047] Optionally, the sensing electrode 301 reciprocates under the drive of the piezoelectric electrode 302 to generate an electrical signal.

[0048] The lead-out electrode 303 inputs an initial driving signal or a next driving signal to the piezoelectric electrode 302. Under the drive of the initial driving signal or the next driving signal, the piezoelectric layer 3020 deforms, causing the elastic beam b300 to swing vertically, thereby driving the sensing electrode 301 to reciprocate vertically in the recessed region 101. When the sensing electrode 301 reciprocates vertically, it generates an electrical signal corresponding to the reciprocating vibration, which is then input to the lead-out electrode 303.

[0049] In this embodiment, preferably, the shape of the sensing electrode 301 is the same as that of the detection electrode 201, both being square structures, and the edge of the sensing electrode 301 adjacent to the detection electrode 201 is the same as the edge of the detection electrode 201 adjacent to the sensing electrode 301 (i.e., the shape, thickness, and length of the edge).

[0050] In this embodiment, since the detection electrode 201 is located near the sensing electrode 301, the detection electrode 201 and the sensing electrode 301 form a capacitor structure. When the sensing electrode 301 reciprocates in the up-down direction, the detection electrode 201 monitors its relative position to the sensing electrode 301 in real time. When the sensing electrode 301 and the detection electrode 201 are on different planes, the capacitance changes, and the detection electrode 201 generates a sensing signal corresponding to the capacitance change, which is then input to the feedback electrode 202. Since the feedback electrode 202 is connected to the control circuit, after the sensing signal is input to the control circuit, the control circuit can determine whether the vibration of the dynamic electrode 3 is in a stable state by analyzing the sensing signal. Example

[0051] like Figure 5 and Figure 6 As shown, this embodiment can be used for any of the electric field sensors described in Embodiments 1 to 3 above. The difference between this embodiment and Embodiment 4 above is that the static electrode 2 and the dynamic electrode 3 are arranged opposite to each other. The first part of the static electrode 2 is attached to the first side of the solid region 100, and the non-moving part of the dynamic electrode 3 is attached to the second side of the solid region 100.

[0052] In this embodiment, the sensing electrode 301 has a square shape, and the detection electrode 201 has a frame shape, surrounding the three edges of the sensing electrode 301. This design improves the sensitivity of real-time monitoring of the relative position between the sensing electrode 301 and the detection electrode 201, allowing the detection electrode 201 to generate a more accurate sensing signal, thereby more accurately determining whether the motion state of the dynamic electrode 3 is stable when sensing the charge signal. Example

[0053] like Figure 7 As shown, this embodiment can be used for any of the electric field sensors described in Embodiments 1 to 3 above. The difference between this embodiment and Embodiment 4 above is that the static electrode 2 includes a first static electrode 4 and a second static electrode 5. The first static electrode 4 includes a first elastic beam 400, a first detection electrode 401 and a first feedback electrode 402. The second static electrode 5 includes a second elastic beam 500, a second detection electrode 501 and a second feedback electrode 502. The first detection electrode 401 and the second detection electrode 501 are both adjacent to the sensing electrode 301. When the sensing electrode 301 and the first detection electrode 401 and the second detection electrode 501 are on different planes, a first sensing signal and a second sensing signal are generated to determine the motion state of the sensing electrode 301.

[0054] Optionally, the position of the first detection electrode 401 corresponds to the position of the second detection electrode 501, or the position of the first detection electrode 401 is adjacent to the position of the second detection electrode 501.

[0055] In this embodiment, preferably, the position of the first detection electrode 401 corresponds to the position of the second detection electrode 501. The first detection electrode 401 is located to the right of the sensing electrode 301 and adjacent to the right edge of the sensing electrode 301. The second detection electrode 501 is located to the left of the sensing electrode 301 and adjacent to the left edge of the sensing electrode 301. The structures of the first elastic beam 400 and the second elastic beam 500 are the same as those of the elastic beam a described above. The structures of the first detection electrode 401 and the second detection electrode 501 are the same as those of the detection electrode 201. The structures of the first feedback electrode 402 and the second feedback electrode 502 are the same as those of the feedback electrode 202.

[0056] After the first and second induction signals are input into the control circuit, by analyzing the first and second induction signals, it can be further determined whether the motion state of the dynamic electrode 3 is stable when the induction charge signal is received. Example

[0057] like Figure 8 and Figure 9 As shown, this embodiment can be used for any of the electric field sensors described in Embodiments 1 to 3 above. The difference between this embodiment and Embodiment 4 above is that the sensing electrode 301 includes a comb structure 3010, the first detection electrode 401 includes a first comb structure 4010, and the second detection electrode 501 includes a second comb structure 5010. The first comb structure 4010 and the second comb structure 5010 are both in cooperation with the comb structure 3010.

[0058] The contact area between the first detection electrode 401 and the second detection electrode 501 and the sensing electrode 301 can be increased by the comb structure 3010, the first comb structure 4010 and the second comb structure 5010.

[0059] In embodiments two through five above, regarding material selection, the substrate layer can be selected from dielectric materials such as silicon-based materials, glass, ceramics, or organic materials, as well as metals and metal alloys. The insulating layer can be selected from silicon dioxide, silicon nitride, or silicon dioxide / silicon nitride composite materials. The piezoelectric layer can be selected from lead zirconate titanate, aluminum nitride, zinc oxide, lead titanate, barium titanate, modified lead titanate, etc. The elastic beam structure can be selected from one or a combination of at least two of the following: straight beam, folded beam, U-shaped beam, serpentine beam, and crab-shaped beam.

[0060] Example 8 like Figure 10 As shown, this embodiment provides a method to ensure the accuracy of the electric field output signal, which can be applied to any of the electric field sensors described in Embodiments 1 to 3 above, and includes the following steps: S100: The static electrode senses the vibration state of the dynamic electrode to output a current sensing signal corresponding to the vibration state. S200: Determine whether the current phase difference between the current sensing signal and the preset sensing signal is the same as the set phase difference. If yes, receive the next sensing signal input by the static electrode. If no, set the P value and I value according to the current phase difference to output the tuning voltage. S300: Based on the tuning voltage output, the next driving signal enables the dynamic electrode to vibrate stably, so as to ensure that the dynamic electrode outputs an accurate electric field signal under the action of the next driving signal.

[0061] In this embodiment, in step S100, the static electrode includes an elastic beam a, a detection electrode, and a feedback electrode, while the dynamic electrode includes an elastic beam b, a piezoelectric electrode, a sensing electrode, and a lead-out electrode. The detection electrode is positioned adjacent to the sensing electrode, forming a capacitor structure. When the sensing electrode reciprocates in the up-down direction, the detection electrode monitors its relative position to the sensing electrode in real time. When the sensing electrode and the detection electrode are on different planes, the capacitance changes, and the detection electrode generates a sensing signal corresponding to this capacitance change. This sensing signal is input to the control circuit through the feedback electrode.

[0062] For example, in step S100, when the number of static electrodes is one, the feedback electrode outputs a sensing signal.

[0063] In addition, when the static electrode is divided into a first static electrode and a second static electrode, the first feedback electrode outputs a first sensing signal and the second feedback electrode outputs a second sensing signal.

[0064] In step S200, both the current sensing signal and the preset sensing signal are capacitor signals. The preset sensing signal can be the next drive signal output by the NCO voltage-controlled oscillator.

[0065] In the phase difference detection module, after the current sensing signal is input into the phase difference detection module, the current phase difference between the current sensing signal and the preset sensing signal is calculated by the phase difference detection module.

[0066] In the comparison module, the current phase difference is compared with the set phase difference. If the current phase difference is the same as the set phase difference, or the current phase difference is close to the set phase difference, the next sensing signal from the static electrode input is received. If the current phase difference is not close to the set phase difference, the current phase difference is input to the loop filter.

[0067] The current phase difference between the current sensed signal and the preset sensed signal is a constant value. If the frequency of the current sensed signal changes, the phase will also change. After the current phase difference is detected and calculated, the current phase difference between the two signals changes, and this change information (i.e., the current phase difference) is input to the loop filter.

[0068] In a loop filter, after the current phase difference is input into the loop filter, the loop filter outputs a tuning voltage based on the P (proportional control) value and I (integral control) value set according to the current phase difference.

[0069] The P (proportional control) value determines the loop filter's response to errors; a larger P value results in a faster system response, but an excessively large P value may cause oscillations. The I (integral control) value accumulates the error of the capacitor signal over a period of time, ensuring that the adjusted capacitor signal error is closer to zero. Since both values ​​are primarily set based on the magnitude of the error, excessively large or small values ​​will affect the normal operation of the control circuit. Therefore, they need to be set according to the actual situation of the electric field sensor.

[0070] In step S300, the NCO voltage-controlled oscillator outputs the next driving signal based on the tuning voltage to drive the sensing electrode to perform stable vibration.

[0071] In this embodiment, steps S100 to S300 can be repeated until the current phase difference is the same as or close to the set phase value.

[0072] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. An improved structure for an electric field sensor, characterized in that, It includes a package housing, an electric field sensitive chip, and a control circuit. The electric field sensitive chip is fixed inside the package housing and connected to the control circuit. The electric field sensitive chip includes at least one electrode assembly, which consists of at least one dynamic electrode and at least one static electrode. The dynamic electrode reciprocates under the drive of an initial driving signal. When the dynamic electrode and the static electrode are in different planes, the static electrode generates and outputs a current sensing signal to determine the vibration state of the dynamic electrode. The control circuit receives and analyzes the input current sensing signal to derive the next driving signal that ensures the dynamic electrode can vibrate stably, so that the dynamic electrode outputs an accurate electric field signal under the action of the next driving signal.

2. The improved structure of the electric field sensor according to claim 1, characterized in that, The control circuit is located outside the package housing and includes a phase difference detection module, a comparison module, a loop filter, and an NCO voltage-controlled oscillator, wherein: The phase difference detection module is connected to the static electrode and is used to receive the current sensing signal input by the static electrode and to obtain the current phase difference based on the current sensing signal and the preset sensing signal. The comparison module is used to compare whether the current phase difference is the same as the set phase difference; The loop filter is used to set the P value and I value according to the current phase difference in order to output a tuning voltage; The NCO voltage-controlled oscillator is connected to the dynamic electrode. The NCO voltage-controlled oscillator inputs the next drive signal derived from the tuning voltage into the dynamic electrode to ensure that the dynamic electrode outputs an accurate electric field signal under the action of the next drive signal.

3. The improved structure of the electric field sensor according to claim 2, characterized in that, The electric field sensitive chip also includes a substrate, wherein: The substrate provides a carrier for the dynamic electrode and the static electrode, and includes a solid region and a recessed region. The dynamic electrode includes a non-vibrating portion attached to the solid region and a vibrating portion attached above the recessed region. The vibrating portion generates an electrical signal when it reciprocates. The static electrode includes a first portion attached to the solid region and a second portion attached above the recessed region, wherein the second portion is adjacent to at least a portion of the vibrating portion, and when the second portion and the vibrating portion are on different planes, the current sensing signal is generated for determining the vibration state of the dynamic electrode.

4. The improved structure of the electric field sensor according to claim 3, characterized in that, The static electrode includes an elastic beam a, a detection electrode, and a feedback electrode, wherein: The elastic beam a includes a first part a attached to the solid region and a second part a attached above the recessed region; The detection electrode is attached to at least a portion of the top end face of the second part a; The feedback electrode is attached to the top end face of the first part a and connected to the detection electrode, receiving and outputting the sensing signal obtained by the detection electrode.

5. The improved structure of the electric field sensor according to claim 4, characterized in that, The dynamic electrode includes an elastic beam b, a piezoelectric electrode, a sensing electrode, and a lead-out electrode, wherein: The elastic beam b includes a first part b attached to the solid region and a second part b attached above the recessed region; The sensing electrode is attached to the top end face of the second part a and adjacent to at least a portion of the detection electrode, wherein the sensing electrode generates an electrical signal during reciprocating vibration; A portion of the piezoelectric electrode is attached to the top end face of the second part a and is located behind the sensing electrode. Another portion of the piezoelectric electrode is attached to the top end face of the second part b. The piezoelectric electrode deforms under the drive of an initial driving signal or a next driving signal. The lead-out electrode is attached to the top end face of the second part b, wherein the lead-out electrode is used to receive the electrical signal input by the sensing electrode and to input the initial drive signal or the next drive signal to the piezoelectric electrode.

6. The improved structure of the electric field sensor according to claim 5, characterized in that, The static electrode includes a first static electrode and a second static electrode. The first static electrode includes a first elastic beam, a first detection electrode, and a first feedback electrode. The second static electrode includes a second elastic beam, a second detection electrode, and a second feedback electrode. The first detection electrode and the second detection electrode are adjacent to the sensing electrode. When the sensing electrode is on a different plane from the first detection electrode and the second detection electrode, a first sensing signal and a second sensing signal are generated to determine the vibration state of the sensing electrode.

7. The improved structure of the electric field sensor according to claim 6, characterized in that, The position of the first detection electrode corresponds to the position of the second detection electrode, or the position of the first detection electrode is adjacent to the position of the second detection electrode.

8. The improved structure of the electric field sensor according to any one of claims 1-7, characterized in that, The packaging housing includes a packaging cover plate and a packaging tube shell, wherein the packaging cover plate is fixed to the top end face of the packaging tube shell by Kovar solder rings to form the packaging structure of the electric field sensitive chip; An adhesive area for fixing the electric field sensitive chip is formed on the inner end face of the package shell, and the package shell is also provided with a plurality of solder points that are respectively connected to the electric field sensitive chip and the control circuit.

9. The improved structure of the electric field sensor according to claim 8, characterized in that, A downwardly extending region is formed on the end face of the encapsulation cover plate facing the encapsulation housing.

10. A method for ensuring accurate electric field output signal, characterized in that, An improved structure applied to the electric field sensor according to any one of claims 1-9 includes the following steps: The static electrode senses the vibration state of the dynamic electrode to output a current sensing signal corresponding to the vibration state; Determine whether the current phase difference between the current sensing signal and the preset sensing signal is the same as the set phase difference. If yes, receive the next sensing signal input by the static electrode. If no, set the P value and I value according to the current phase difference to output the tuning voltage. The next driving signal, based on the tuning voltage output, enables the dynamic electrode to vibrate stably, thereby ensuring that the dynamic electrode outputs an accurate electric field signal under the action of the next driving signal.

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