55 results about "Interdigital capacitor" patented technology

The invention provides an implantable wireless passive blood pressure monitoring device, which relates to the technical field of blood pressure detection and comprises a blood pressure sensor and an in-vitro reading device, the blood pressure sensor comprises an outer inductance coil and an internal interdigital capacitor; the inductance coil is connected with the interdigital capacitor through a cross-layer line to form a capacitance-inductance LC loop; the inductance coil and the interdigital capacitor are packaged in the soft base material silicon rubber; the blood pressure sensor is used for being attached to the outer wall of an artery blood vessel, and the resonant frequency of the blood pressure sensor can change along with compression tensile deformation of the blood vessel; the in-vitro reading device is used for reading the resonant frequency of the blood pressure sensor; wherein the resonant frequency read by the in-vitro reading device is used for calculating a blood pressure value. The implantable wireless passive blood pressure monitoring device provided by the invention is used for providing a blood pressure monitoring mode with high measurement precision and small trauma so as to improve the accuracy and comfort of blood pressure monitoring.

The present invention discloses a terahertz dynamic inductive thermal radiometer, comprising a superconducting thin film layer, a terahertz antenna, a cutoff layer, and a Si substrate. The superconducting thin film layer and the terahertz antenna are respectively deposited on the cutoff layer, which is deposited on the Si substrate. The superconducting thin film layer includes a superconducting feeder, an interdigital capacitor, and an inductor coil. The interdigital capacitor and the inductor coil are connected in parallel to form an oscillating circuit. The terahertz antenna is adjacent to the inductor coil and is used to convert received terahertz signals into heat, causing the inductor coil to produce an inductance change. This inductance change causes the resonant frequency within the interdigital capacitor to change. The superconducting feeder receives the changed resonant frequency, and the changed resonant frequency can be used to obtain the light intensity of the terahertz signal, thereby completing terahertz signal detection. The terahertz dynamic inductive thermal radiometer can accurately detect terahertz signals and is less affected by temperature. The present invention also provides a method for preparing the terahertz dynamic inductive thermal radiometer and a terahertz detection system.

The invention discloses a surface acoustic wave resonator and a filter. The resonator comprises an interdigital transducer arranged on a piezoelectric substrate, reflecting gratings located on the two sides of the interdigital transducer and at least one laminated protection structure arranged in the outer side area of the reflecting gratings. The laminated protection structure comprises an interdigital capacitor arranged on the surface of the piezoelectric substrate and an organic material layer covering the interdigital capacitor; two bus bars of the interdigital capacitor are electrically connected with two signal ports of the resonator respectively, and the interdigital capacitor is connected with the interdigital transducer in parallel. According to the invention, the anti-ESD capability of the resonator can be effectively improved under the condition of not increasing additional process steps and not changing the electrode structure of the normal working area of the resonator.

The invention relates to the technical field of flexible electronic sensors, in particular to a flexible large strain sensor for crack detection and a preparation method thereof.The flexible large strain sensor comprises a skeleton-shaped packaging layer, the packaging layer comprises two rigid fixing ends, and the two rigid fixing ends are integrally connected through a sensitive unit section; a rigid reinforcing structure is embedded in each rigid fixing end, mechanical fixing holes are formed in each rigid fixing end and the corresponding rigid reinforcing structure in a penetrating mode, interdigital capacitor electrodes are embedded in the sensitive unit sections, and the interdigital capacitor electrodes are made of flexible conductive materials through laser ablation. The end part of the interdigital capacitor electrode is connected with a flexible extension wire, the tail end of the flexible extension wire is connected with an external lead, and the external lead is embedded between the packaging layer and the upper surface of the rigid fixed end; the problems that an existing flexible sensor is unstable in installation, contradictory in measuring range and precision and poor in environmental adaptability in structural crack detection are solved.

This invention discloses a wireless, passive, and visualized cerebrospinal fluid drainage tube flow monitoring sensor, system, and fabrication method, belonging to the field of biomedical sensing and microelectromechanical systems (MEMS) technology. It includes a flexible substrate, an interdigital capacitor-open resonant ring structure disposed on the substrate surface, and a microchannel pressure conversion structure bonded to it; the microchannel corresponds vertically to the position of the interdigital capacitor. The pressure generated by the cerebrospinal fluid flow drives the displacement of the liquid metal, modulating the equivalent dielectric constant of the interdigital capacitor and causing a resonant frequency shift. The frequency drift is wirelessly read by an external device, and the flow rate is calculated using an algorithm, achieving passive wireless continuous monitoring. This invention, employing the aforementioned sensor, system, and fabrication method, solves the problems of high infection risk, low accuracy, and inability to continuously monitor existing drainage monitoring methods that rely on manual observation or wired sensors. It has the advantages of high sensitivity, flexible integration, and good safety.

This application belongs to the field of microwave engineering, specifically relating to a dual-polarization, reconfigurable, stealthy, and transparent integrated frequency selective surface and radome. The frequency selective surface consists of a three-layer structure: an adjustable FSS layer, an adjustable impedance layer, and a non-adjustable impedance layer. A PIN diode is loaded in the adjustable layer, while a resistor is loaded in the impedance layer. A spiral resonator and an interdigital capacitor resonator are used in the non-adjustable and adjustable impedance layers, respectively. Metal structures arranged in the x and y directions are placed on both sides of the adjustable impedance layer to achieve dual polarization. The adjustable FSS layer forms a transmission window and has reconfigurable functionality. Utilizing the PIN diode and multi-layer structure design, the switching between transmission and absorption functions in the X-band is achieved, realizing a stealthy and transparent integrated design. Transmission and absorption modes can be switched in the X-band, achieving integrated stealth functionality. The radome, through this frequency selective surface, possesses both transmission and absorption capabilities and reconfigurable characteristics.

The invention discloses an interdigital capacitor and an analog-to-digital conversion circuit, and the interdigital capacitor comprises at least one first metal layer, and each first metal layer is provided with a first electrode, at least one piece of first interdigital metal connected with the first electrode, a second electrode, and a plurality of pieces of second interdigital metal connected with the second electrode. And at least one third interdigital metal connected with the second electrode. Wherein the at least one piece of first interdigital metal and the plurality of pieces of second interdigital metal are alternately arranged to form a capacitor, and the at least one piece of third interdigital metal is dummy interdigital metal.

The invention discloses a terahertz detection unit based on a dielectric couple two-level system and an array detector. The array detector comprises an array composed of resonance detection units. The resonance detection unit comprises a broken line inductor, an interdigital capacitor and a coupling feeder line which are connected, and a dielectric layer and an absorber are stacked on the interdigital capacitor. Wherein the absorber is located above the dielectric layer, so that the dielectric layer isolates the interdigital capacitor from the absorber; and the broken line inductor, the interdigital capacitor, the coupled feeder line and line bodies connected among the components are all made of superconducting materials. The absorber is a grid body made of a non-superconducting metal material. After the absorber is used for receiving terahertz radiation, energy is transmitted to the dielectric medium, a dipole two-energy-level system in the dielectric medium is changed, the dielectric constant of the dielectric medium is changed, then the resonant frequency of the resonance detection unit is changed, and terahertz wave detection and imaging are achieved by analyzing the change of the resonant frequency of the resonance detection unit.

The invention is suitable for the technical field of cable life evaluation, and provides a cable life evaluation device and method based on interdigital sensing, and the method comprises the following steps: coupling an interdigital capacitor plate to a to-be-measured cable, and measuring values and capacitance values at a plurality of frequencies through an LCR digital bridge; processing the capacitance value by using a KNN algorithm, and judging the damage state of the cable; carrying out linear compensation correction on a measured value by combining prior knowledge of the cable; inputting the compensated and corrected value into a pre-trained DT regression model to obtain an aging degree evaluation result of the cable; and fusing the judgment result of the damage state and the evaluation result of the aging degree, and outputting the residual life pre-evaluation of the cable. According to the method, rapid, lossless and accurate detection of the waste cable is realized, and a reliable basis is provided for recycling and screening of the cable.

The invention discloses an analog-to-digital conversion circuit based on small value priority and a double-end differential capacitor. The analog-to-digital conversion circuit comprises a quantization mode control circuit, a digital-to-analog converter, a main comparator, a successive approximation type logic circuit, an asynchronous clock generation circuit and a quantization code register, wherein the quantization mode control circuit outputs a quantization mode according to the magnitude of input voltage; each of two double-end differential capacitor arrays in the digital-to-analog converter comprises N capacitor assemblies with capacitance values in binary distribution, each capacitor assembly comprises two interdigital capacitors which share an upper polar plate and are independent in lower polar plate, and the digital-to-analog converter outputs differential voltage; the main comparator outputs a comparison result of the differential voltage; the successive approximation type logic circuit controls the voltage connected with the lower polar plate of the capacitor assembly and the number of the capacitor assemblies contributing the weight in the digital-to-analog converter according to the comparison result and the quantization mode; the quantized code register generates a quantized code according to the comparison result. According to the invention, the power consumption, hardware overhead and circuit complexity of the analog-to-digital converter are effectively reduced.

This invention discloses a microwave non-contact fed strain detection sensor for metal devices, comprising a vector network analyzer and a waveguide antenna connected thereto; a metamaterial array is arranged at a relative position to the waveguide antenna, and a feeding network is arranged on the side of the metamaterial array away from the waveguide antenna; the feeding network receives signals from the metamaterial array and outputs the signals to an interdigital strain sensing probe; the metal device under test is arranged on the side of the interdigital strain sensing probe away from the feeding network; the metamaterial array includes a dielectric substrate and radiating elements arranged in a periodic array on the surface of the dielectric substrate; the radiating elements are circular ring structures with a single opening, and the opening directions of the radiating elements are consistent; this invention has a simple structure, high electromagnetic signal capture efficiency, and an output shaft with an open structure, which can improve the output efficiency by 9.8% compared with traditional feeding networks; the interdigital capacitors provided have a more compact structure, lower profile, and stronger resonance characteristics.

The invention relates to the technical field of intelligent beekeeping, and discloses a mature honey standardized production control system based on strong group multiple box bodies, which comprises a dielectric spectrum sensing array integrated on a comb foundation, a data acquisition module, a central processing module and a user interface module. According to the system, the micro interdigital capacitor unit is used for independently detecting electromagnetic characteristics of substances in cells, the central processing module obtains complex impedance spectroscopy and temperature data, a content classification model and a polynomial regression model containing temperature cross terms are operated in parallel, the types of the contents in the cells are recognized, and the water content of honey is accurately calculated. The system establishes data mapping between a super production area and a hive breeding area, respectively calculates a mature honey harvest index and a breeding health degree score, and automatically generates a honey extraction recommendation or a health alarm. According to the invention, lossless, in-situ and high-resolution monitoring of the internal state of the beehive is realized, and the problems that the bee colony is interfered by manual box opening and the honey maturity is lack of quantitative standards are solved.

The invention provides a broadband wide-axial-ratio circularly polarized antenna based on a tight coupling principle, and relates to the technical field of microstrip antenna structure design, the broadband wide-axial-ratio circularly polarized antenna comprises a first dielectric plate as a substrate, and a feed network capable of realizing one-to-four power division and 90-degree phase shift is printed on the lower bottom surface of the first dielectric plate; a second dielectric plate is arranged above the first dielectric plate in parallel, four arc-shaped metal patches are arranged on the lower bottom surface of the second dielectric plate to form a radiation unit, and the adjacent patches are tightly coupled through an interdigital capacitor; and a strip-shaped microstrip line is arranged on the upper top surface of the second dielectric plate. And the four coaxial feeder lines are vertically connected with the output end of the feed network and each metal patch, so that high-efficiency transmission of signals is realized. The upper surface of the first dielectric plate is provided with an annular metal cavity which is connected with the metal ground and is used for improving the axial ratio at a low elevation angle. According to the invention, wide impedance bandwidth and wide axial ratio bandwidth are realized, and the antenna has wide axial ratio beam width and high radiation efficiency.

The invention belongs to the technical field of microwaves, and particularly relates to a slot line-half-mode SIW composite transmission line for microwave / millimeter wave transmission, which is characterized in that a half-mode SIW structure is arranged in a sandwich structure, and a first metal layer synchronously loads a conical microstrip feeder line and a horn-shaped microstrip feeder line structure; the second metal layer is used as a metal structure with a floor function, and the design mode of additionally loading a slot line and an interdigital capacitor enables the device to realize transmission of an S wave band and a Ka wave band at the same time. Wherein in the S wave band, the horn-shaped micro-strip structure of the first metal layer is used for carrying out coupled feeding on the slot line, and in the Ka wave band, the conical micro-strip structure of the first metal layer is used for directly feeding the half-mode SIW; meanwhile, the second metal layer loads an interdigital capacitor at the tail end of the half-mode SIW to complete filtering, and finally the composite transmission line feed structure supporting synchronous transmission of the half-mode SIW and the slot line is constructed. The machining process is simplified, and the machining cost is reduced.

This invention discloses a cross-shaped microstrip filter, belonging to the field of microwave RF passive device technology. The filter includes a dielectric substrate, an input microstrip line, an output microstrip line, two sets of series-arm resonant units, and two sets of parallel-arm resonant units. The series-arm resonant units are composed of microstrip inductors and interdigital capacitors connected in series, with the resonant frequency corresponding to the filter's center frequency. The parallel-arm resonant units are composed of microstrip inductors and surface-mount capacitors connected in series, generating low-frequency and high-frequency transmission zeros respectively. The four sets of resonant units converge at a common node to form a cross-shaped topology. This invention, through a modular cross-shaped architecture, allows direct mapping between the resonant units and the frequency response, simplifying debugging and increasing design efficiency. Modular cascading can achieve high-order filtering, significantly improving band-edge steepness and stopband suppression, making it suitable for microwave RF systems such as communication, radar, and satellite navigation.

The invention relates to a special tool for testing and trimming mass distribution defects of an uncoated harmonic oscillator, and belongs to the field of testing and trimming of quartz hemispherical harmonic oscillators. The lower base and the upper base are each of a cylindrical structure which is vertically arranged in the axial direction. The upper base is coaxially arranged at the top of the lower base; the transmission shaft is axially and vertically arranged at the axis of the upper base and the lower base; the two groups of ball bearings sleeve the upper and lower ends of the transmission shaft respectively; the ball bearing located on the upper portion is arranged on the inner wall of the upper base. The ball bearing located on the lower portion is arranged on the inner wall of the lower base. Taper holes are formed in the top ends of the transmission shafts; the collet chuck is embedded into the taper hole; the locking nut is sleeved on the outer wall of the joint of the collet and the transmission shaft; the interdigital capacitor seat is coaxially arranged at the top end of the upper base; the interdigital capacitor is coaxially mounted at the top of the interdigital capacitor seat; the fixed stud is mounted at the top of the collet chuck; according to the invention, the uncoated harmonic oscillator and the interdigital capacitor can be fixed, the harmonic oscillator can rotate relative to the interdigital capacitor, and the gap between the harmonic oscillator and the interdigital capacitor is ensured.

In wafer-to-wafer bonding, a first die is bonded to a second die at a bonding interface. Various configurations of capacitors are placed along an inner portion of an edge seal of the bonded dies to detect a discontinuity in the bonding interface. These configurations include interdigitated capacitors, which can be horizontally or vertically oriented, parallel-digitated capacitors, and pillars forming a parameter around the dies with conductive portions offset from the pillar and extending inside the dies. Other configurations can be used.

The application discloses a superconducting quantum capacity detector with large saturated power, which comprises a reference ground, a coplanar waveguide transmission line, a superconducting microwave resonator based on a tantalum film and a single Cooper pair box based on aluminum, the superconducting microwave resonator comprises a double helix inductor and an interdigital capacitor, the single Cooper pair box is connected to the interdigital capacitor through aluminum metal wires, the single Cooper pair box and the double helix inductor are located on the same side of the interdigital capacitor, and the single Cooper pair box is located above the double helix inductor, so that the detector unit is more compact, the space utilization is increased, and the number of pixels of a multi-pixel focal plane detector array is increased; the gate capacitor is designed in the shape of a tuning fork, compared with an existing parallel wire structure, double capacitance values can be obtained without increasing the volume of a superconducting island, the smaller the volume of the superconducting island is, the more significant the quantum capacity effect of the detector is, and the more obvious the response is, the larger the gate capacitor is, and the larger the saturated power of the detector is, so that the saturated power can be increased without losing sensitivity.

The technology described herein is generally directed towards reconfiguring apertures of reconfigurable intelligent surfaces (metasurfaces) using surface acoustic waves to change metal-insulator-transition material (e.g., vanadium dioxide (VO2)) to a lower resistance state. Reconfigurability of unit cells' resonator apertures is achieved by generating surface acoustic waves per unit cell, via a unit cell capacitor (e.g., interdigitated capacitor) coupled to a low frequency control signal. The presence of the surface acoustic waves stresses the (e.g., VO2) material enabling current flow on the aperture (hence resonance) when subject to an incoming electromagnetic wave. Removal of the control signal results in the metal-insulator-transition material (e.g., VO2) changing to a higher resistance state that blocks the current flow (no resonance). The VO2-based design can be used in a single metasurface configuration, or in a stack of reconfigurable metasurfaces to select among different metasurface configurations that facilitate different beam shaping, beam gain, and / or other beam characteristics.

A self-calibration humidity sensor comprises a substrate, a first insulating layer coated on the substrate, a heating device arranged on the first insulating layer, a second insulating layer coated on the heating device and separated from the first insulating layer, a reference capacitor arranged on the second insulating layer, and a humidity sensing capacitor arranged on the second insulating layer and at the same time arranged above the heating device. The humidity sensing capacitor comprises an interdigital capacitor arranged on the second insulating layer and a layer of humidity sensitive material coated on the interdigital capacitor. By arranging the reference capacitor and the humidity sensing capacitor, the water vapor adsorbed in the layer of humidity sensitive material is evaporated by heating the layer of humidity sensitive material on the humidity sensing capacitor, so that the capacitance value of the humidity sensing capacitor returns to the value of the initial non-humid state, and the calibration of the parameter value of the humidity sensing capacitor is realized by comparison with the reference capacitor, finally realizing the automatic calibration of the humidity sensor, providing the accuracy of the humidity measurement, and avoiding or weakening the measurement error.

The invention provides an intracranial pressure sensor based on a split-ring resonator structure, a monitoring system and a monitoring method, and belongs to the technical field of medical instruments. The intracranial pressure sensor is composed of a substrate, an interdigital capacitor-split resonant ring structure and a micro-channel pressure conversion structure. Intracranial pressure acts on the micro-channel film to drive the gallium-indium eutectic alloy to displace, the interdigital capacitance is modulated in real time, resonant frequency deviation is caused, and 0.47 MHz / kPa high-sensitivity pressure monitoring is achieved. The monitoring system comprises an intracranial pressure sensor, an in-vitro radio frequency read-write device and a data processing terminal, and the intracranial pressure can be continuously monitored in real time for a long time. Compared with an existing intracranial pressure detection means, the intracranial pressure sensor based on the split-ring resonator structure, the monitoring system and the monitoring method have the advantages that high sensitivity, high stability, good repeatability and excellent wireless readability are achieved on the basis that an integrated chip is not needed, and a better solution is provided for high-precision minimally invasive intracranial pressure monitoring.

The invention discloses a microstrip band-stop filter with a wide upper passband, and relates to the technical field of radio frequency passive devices, and the microstrip band-stop filter comprises an electromagnetic shielding cavity, a dielectric substrate, a microstrip circuit located on the front surface of the dielectric substrate, and a grounding metal layer located on the back surface of the dielectric substrate. The microstrip circuit is composed of an input feeder line, an output feeder line and a four-stage cascade filter network located between the input feeder line and the output feeder line. The stopband center frequencies of the four filtering units are distributed in a staggered manner so as to broaden the stopband bandwidth; each filtering unit is composed of two U-shaped micro-strips and an interdigital capacitor, and symmetrical rectangular split ring resonators loaded with the interdigital capacitors and double-path arc-shaped parallel micro-strip lines are adopted at the interstage connecting positions of the filtering units respectively. According to the invention, the low insertion loss, high selectivity and miniaturization design of the filter are realized, and the technical problem that the existing band elimination filter is difficult to adapt to a complex and changeable signal environment due to the limited passband width is solved.

Certain aspects of the present disclosure provide an electro-acoustic device and a method of manufacturing such an electro-acoustic device. One example electro-acoustic device generally includes a piezoelectric layer (430), a surface acoustic wave (SAW) resonator (410) disposed above the piezoelectric layer, a non-piezoelectric region (440) disposed adjacent to the piezoelectric layer, and an interdigital transducer capacitor (420) IDC electrically coupled to the SAW resonator and disposed above the non-piezoelectric region.

The invention discloses a compact cavity filter introducing a transmission zero point in a straight-line mode, which comprises an electromagnetic resonant cavity, N-1 coupling control units and N frequency fine tuning units, and N is greater than or equal to 2; the electromagnetic resonant cavity comprises a metal cavity and N resonant rods, the metal cavity is a closed inner cavity formed in a metal block, the interior of the metal cavity is linearly divided into N areas in the left-right direction, the N resonant rods are embedded in the N areas in a one-to-one correspondence mode, and each resonant rod and the inner wall of the metal cavity in the area where the resonant rod is located define a resonant cavity unit; one coupling control unit is arranged between every two adjacent resonant cavity units; the N frequency fine tuning units are in one-to-one correspondence with the N resonant cavity units; a first interdigital capacitor structure is arranged between the top of each resonance rod and the inner top surface of the metal cavity, and a second interdigital capacitor structure is arranged between the front side surface of each resonance rod and the inner wall of the front side of the metal cavity; the invention has the advantages of compact structure and small overall size.

The utility model provides a PCB structure of a network socket capable of reducing crosstalk caused by open twisting of Ethernet twisted pairs, which comprises a first PCB layer, a second PCB layer, a third PCB layer and a fourth PCB layer, and each layer comprises two groups of signal transmission ends which are respectively provided with eight signal transmission ends and are communicated through a transmission line; wherein the first PCB layer comprises a first filtering area, the second PCB layer comprises a second filtering area, the third PCB layer comprises a third filtering area, and the fourth PCB layer comprises a fourth filtering area; each filtering area forms a plurality of interdigital capacitors through transmission line structures of two signal transmission ends so as to reduce crosstalk. The PCB structure of the network socket capable of reducing crosstalk caused by open twisting of the Ethernet twisted pair provided by the utility model has the remarkable beneficial effects that the signal transmission quality is improved, the cost is reduced, and the design flexibility and the product competitiveness are also improved.

The invention discloses a semiconductor device and a preparation method thereof, a radio frequency chip and electronic equipment. The semiconductor device comprises a substrate; the first dielectric layer is located on the substrate; the patterned first film layer is located on the first dielectric layer, and the first film layer comprises a plurality of heating electrodes and a plurality of interdigital capacitors; the second dielectric layer is located on the first film layer and the first dielectric layer; the patterned second film layer is located on the second dielectric layer, the second film layer comprises a plurality of phase change material layers, and the projections of the plurality of phase change material layers on the first film layer coincide with the plurality of heating electrodes respectively; the third dielectric layer is located on the second film layer and the second dielectric layer; and the patterned third film layer is located on the third dielectric layer and comprises a plurality of first lead-out bonding pads, a plurality of second lead-out bonding pads, a third lead-out bonding pad and a fourth lead-out bonding pad. According to the technical scheme provided by the invention, an adjustable capacitance function can be realized, and better insertion loss performance and higher isolation are achieved.

The present invention discloses a millimeter-wave dual-band voltage-controlled oscillator that integrates localized surface plasmons. The millimeter-wave dual-band voltage-controlled oscillator includes a localized surface plasmon with a notch, a cross-coupling active circuit, a capacitor frequency modulation circuit, and a switching circuit. A switching circuit is loaded at the notch of the localized surface plasmon to achieve resistance shearing, the resonant mode of the localized surface plasmon, and thus switch the frequency band of the voltage-controlled oscillator; in each sub-band, a varactor is connected in series with an interdigital capacitor to achieve a precise frequency modulation function. The present invention integrates the localized surface plasmon and the cross-coupling circuit into one to form an oscillation circuit. Based on the high-quality resonance mechanism of the localized surface plasmon, the quality factor of the overall resonant cavity of the voltage-controlled oscillator is improved.

The utility model discloses a low-temperature medium liquid level sensor, and belongs to the field of liquid level measurement. The low-temperature medium liquid level sensor comprises a measuring capacitor, a gas phase reference capacitor, a liquid phase reference capacitor, a substrate and a capacitance detection circuit, the gas-phase reference capacitor and the liquid-phase reference capacitor are respectively arranged at the upper end and the lower end of the back surface of the substrate; the measuring capacitor, the gas-phase reference capacitor and the liquid-phase reference capacitor all adopt interdigital capacitors and are all connected to the capacitance detection circuit; and the capacitance detection circuit receives real-time capacitance values of the measuring capacitor, the gas phase reference capacitor and the liquid phase reference capacitor, and calculates to obtain a liquid level value after real-time calibration. The gas-phase dielectric constant and the liquid-phase dielectric constant are measured synchronously, the measured liquid level is calibrated, and the measurement precision is improved; and an interdigital capacitor is adopted, so that the sensitivity of the liquid level sensor is improved.

The invention relates to the field of accelerometers, in particular to a vertical variable-area differential capacitive accelerometer, which comprises an external frame, a flexible support beam assembly, a sensitive mass block and an interdigital capacitor electrode, the sensitive mass block and the external frame form a symmetrical suspension type rigid connection structure through a flexible supporting beam assembly, and the upper side and the lower side of the symmetrical suspension type rigid connection structure are respectively provided with interdigital capacitance electrodes; the interdigital capacitor electrode comprises a plurality of movable electrode plates which synchronously move along with the sensitive mass block, and a plurality of fixed electrode plates which are fixed on the external frame and are arranged with the plurality of movable electrode plates in a penetrating manner; when the sensitive mass block generates displacement under the action of acceleration in the z-axis direction, the sensitive mass block drives the movable electrode plates on the upper side and the lower side of the sensitive mass block to move relative to the corresponding fixed electrode plates, so that the lateral effective overlapping areas of the interdigital capacitor electrodes on the upper side and the lower side of the sensitive mass block respectively generate linear changes in opposite directions; therefore, a differential capacitance signal in a linear relation with the displacement of the sensitive mass block is output.