144 results about "Parallel resonance" patented technology

The invention discloses a symmetrical structure S-band filter based on GaAs IPD, which belongs to the technical field of microwaves and comprises a first-order series resonance circuit, a coupling capacitor C1, a grounding inductor L2, a coupling capacitor C2, a second-order parallel resonance, a third-order parallel resonance, a grounding capacitor C6, a coupling capacitor C7, a fourth-order parallel resonance, a grounding capacitor C66, a fifth-order parallel resonance, a coupling capacitor C22 and a grounding inductor L22. And a coupling capacitor C11 and a sixth-order series resonance. The third-order parallel resonance and the fourth-order parallel resonance can improve the low-frequency out-of-band suppression degree of the band-pass filter; the first-order series resonance and the sixth-order series resonance as well as the second-order parallel resonance and the fifth-order parallel resonance can improve the high-frequency out-of-band suppression degree of the band-pass filter.

The invention discloses a current source type LCCL double-frequency resonance system and a parameter matching method thereof, which are suitable for synchronous double-frequency induction quenching of complex workpieces such as gears. The system is composed of two current type resonant inverters working at a low frequency and a high frequency respectively and a dual-frequency LCCL resonant cavity, and dual-frequency current superposition is realized through parallel output. The double-frequency LCCL resonant cavity has two parallel resonance points, a mode based on simplified topology is adopted to simplify parameter design, and meanwhile design errors are maintained at a low level. A power matching coefficient is introduced, the ratio of high-frequency output power to low-frequency output power is adjusted by adjusting the value of the power matching coefficient, and the problem of double-frequency power unbalance caused by frequency variation characteristics of load equivalent resistance and the like is solved. The superposed double-frequency current forms a low-frequency envelope embedded high-frequency oscillation composite waveform on the induction heating coil, cooperative control of tooth root deep quenching (low frequency) and tooth surface hard quenching (high frequency) is achieved, and the method has the advantages of being simple in parameter design, high in power decoupling performance, high in operation stability and the like.

The invention relates to the technical field of radio frequency integrated circuits, in particular to a harmonic suppression power amplifier combining a matching network and a feed network, which comprises a transistor, an input matching module, an output matching module, a stabilizing module and a bias module, the input matching module comprises a first parallel resonance unit, the first parallel resonance unit is used for second harmonic suppression, the output matching module comprises a series resonance unit and a second parallel resonance unit, the series resonance unit is used for resonating at a second harmonic frequency and performing low-impedance grounding on the second harmonic, and the second parallel resonance unit is used for resonating at a second harmonic frequency and performing low-impedance grounding on the second harmonic. The second parallel resonance unit is used for resonating at a third harmonic frequency and forms a high-impedance open circuit for the third harmonic, the output matching module is coupled to a drain electrode of the transistor, and the bias module comprises a grid bias sub-module and a drain bias sub-module. The grid bias sub-module is coupled to a connection node of the input matching module and the grid of the transistor, the drain bias sub-module is coupled to the output matching module, and the bias voltage of the transistor is jointly determined by the grid bias sub-module and the drain bias sub-module. The power amplifier has the effect of improving the efficiency level of the power amplifier while realizing harmonic suppression optimization.

The invention relates to the technical field of resonance analysis, in particular to an effectiveness evaluation method and device for a parallel resonance suppression scheme of a power system. According to the method, the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index are constructed, and the corresponding feasible region is constructed, so that the parallel resonance suppression effect of the access node of the resonance suppression method and the parallel resonance action effect of other surrounding nodes are evaluated. The problems that an application scene of an existing resonance suppression method is limited, and a parallel resonance scene is not matched with the resonance suppression method are solved.

A filter circuit, a filter and a communication device relate to the technical field of communication. The filter circuit includes a series branch connected between the first port and the second port and including a series resonance circuit and a series impedance element connected in series with each other, wherein the series resonance circuit includes a series resonator; and a parallel branch connected between a parallel node and a ground potential and including a parallel resonance circuit and a parallel impedance element connected in series with each other, wherein the parallel resonance circuit includes a parallel resonator, and the parallel node is located on a connection path of the first port and the second port; wherein the resonance frequency of the series resonator is less than the resonance frequency of the parallel resonator.

A high-gain automatic phase modulation quartz vibrating beam accelerometer control circuit comprises a feed-through suppression module, the feed-through suppression module and a quartz vibrating beam resonator form a parallel resonance unit, and the output of the parallel resonance unit is connected with the input of a front-end amplification module. The output of the front-end amplification module is connected with the input of the high-pass filtering module and the first input of the automatic phase control module, the output of the high-pass filtering module is connected with the first input of the dynamic phase shift module, and the second input of the dynamic phase shift module is connected with the output of the automatic phase control module. The output of the dynamic phase shift module is connected with the input of the differential driving module through the low-pass filtering module, the square wave shaping module and the amplitude control module; the output of the differential driving module is connected with the input of the feed-through suppression module, the driving end of the quartz vibrating beam resonator and the second input of the automatic phase control module; according to the invention, low-noise driving of the high-impedance quartz vibrating beam is realized, and the loop phase error is dynamically compensated to improve the stability and resolution of the accelerometer.

The invention discloses a series-parallel resonance characteristic evaluation method and system, and belongs to the technical field of distributed new energy grid-connected power generation, and the method comprises the steps: analyzing the interaction between all units of a microgrid system based on a transfer function method; the method comprises the following steps: performing series resonance modal analysis and parallel resonance modal analysis on a micro-grid system by using a modal analysis method, and constructing a modal analysis equivalent model; extracting resonance modal information according to the modal analysis equivalent model; a resonance center is positioned based on series-parallel modal analysis, resonance types are distinguished in combination with a transfer function method, and resonance characteristic evaluation is realized. According to the method, the resonance type and the resonance center of the micro-grid system can be accurately obtained in the island operation mode, key information such as the key resonance mode and the node participation factor is extracted, and a theoretical basis is provided for subsequent resonance suppression.

The present disclosure relates to apparatuses, systems, and methods for improving frequency measurements during the reverberation period of an ultrasonic transducer. Embodiments of the invention include a primary short circuit (PSC) coupled to a primary side of a transformer and a damping element coupled to a transducer, the transducer being coupled to a secondary side of the transformer, the damping element being configured to damp a received signal during a portion of the reverberation period. The PSC and the damping element may be enabled substantially simultaneously. Enabling the PSC circuit alleviates a parallel resonance that would otherwise be partially generated in the transducer, but increases the received signal by a DC offset voltage. The damping element damps the DC offset voltage. The received signal may be damped before the received signal is amplified by an amplifier. The damping facilitates earlier and more accurate measurement of at least one operating characteristic of the PAS sensor during the reverberation. Another embodiment prevents the DC offset voltage by selectively enabling the PSC within a determined time of a zero crossing of a given signal.

The present invention discloses a high-voltage DC circuit topology. In the high-voltage DC circuit topology, the positive pole of the DC power supply DC is connected to the positive terminal of the bus capacitor C0 via the diode D1, and the negative pole is connected to the negative terminal of the bus capacitor C0; the positive terminal of the bus capacitor C0 is connected to the common drain of the fault current limiting unit and the full-bridge circuit, and the negative terminal is connected to the common source of the full-bridge circuit to form a radio frequency oscillator. The primary winding of the radio frequency transformer T1 is connected in parallel with the tuning capacitor C2. The radio frequency feed electrode a is connected to the a end of the first secondary winding of the radio frequency transformer, and the radio frequency feed electrode b is connected to the b end of the second secondary winding of the radio frequency transformer. A voltage multiplier is placed between the radio frequency feed electrode a and the radio frequency feed electrode b to achieve voltage superposition. The voltage multiplier is composed of a cascade of multiple radio frequency energy coupling electrodes and radio frequency rectifiers. One end of the parallel resonance filter is connected to the last-stage radio frequency energy coupling electrode of the voltage multiplier, and the other end is connected to the load to achieve a DC voltage with low ripple on the load.

The invention relates to the technical field of power transistor output matching, in particular to a power transistor circuit and an integrated power transistor, the power transistor circuit comprises a power transistor body, a parallel resonance circuit and a second lead; the drain electrode of the power transistor body is electrically connected with the first end of the parallel resonance circuit, and the source electrode of the power transistor body is electrically connected with the second end of the parallel resonance circuit; when the drain electrode of the transistor body outputs a waveform, a standing wave is formed on a resonant circuit formed by a parasitic capacitor between the drain electrode and the source electrode of the transistor body and the parallel resonant circuit. Standing waves are generated through the resonance effect of the parallel resonance circuit, so that the efficiency of the power transistor is improved, and impedance matching is achieved.

The utility model discloses a parallel resonance type suction silencer for a refrigerator compressor, which comprises a shell, the shell comprises an upper cavity cover and a lower cavity seat, a cavity partition plate is connected between the upper cavity cover and the lower cavity seat, an inner cavity of the shell is divided into an upper cavity and a lower cavity through the cavity partition plate, the top of the upper cavity cover is connected with an exhaust pipe, and the top of the lower cavity is connected with an exhaust pipe. One side of the lower cavity seat is connected with an air suction pipe, the cavity partition plate is connected with a communicating pipe assembly communicating the upper cavity with the lower cavity, the communicating pipe assembly comprises a plurality of communicating pipes connected in parallel, each communicating pipe is provided with a plurality of resonant cavity slits, and the resonant cavity slits in the communicating pipes are partitioned in different independent spaces through a plurality of partition plates. The design of the communicating pipes connected in parallel is adopted, holes are formed in the pipe walls, and meanwhile the partition plates are added to divide the space; according to the design, the air suction efficiency of the silencer can be improved, and the characteristic noise reduction capacity in a wide frequency band can be improved through the resonance effect of the Helmholtz cavity; and the flow channels among different cavity spaces have the noise reduction effect of the expansion cavity.

The invention relates to a treatment device and a radio frequency beauty instrument using the same, the treatment device comprises a detachable cold air tank, a control module, a touch screen, a radio frequency power amplification circuit, an automatic boost-buck power supply module, a power supply module and a switching interface, the control module is electrically connected with the touch screen and the automatic boost-buck power supply module; the input end of the radio frequency power amplification circuit is connected with the output end of the automatic buck-boost power supply module, the output end of the radio frequency power amplification circuit is connected with the adapter interface, and the radio frequency power amplification circuit is a symmetrical series-parallel resonance circuit and comprises a high-frequency isolation transformer, a third inductor, a capacitor and a parallel resonance circuit. The input end of the parallel resonance circuit is connected with the output end of the automatic buck-boost power supply module, the parallel resonance circuit is composed of a first circuit and a second circuit which are arranged in parallel, and each of the first circuit and the second circuit comprises a universal capacitor, a resonant capacitor, a switching tube and an inductor. The capacitor, the general capacitor, the resonant capacitor, the switching tube and the third inductor form a resonant cavity of the whole circuit topology.

The present invention discloses a method for wireless charging over - load protection, including a receiving process, a starting process, a charging voltage control process, an adapter control unit process, and a battery over - load protection process. It is characterized in that: The resonant inductor L1 receives the energy sent by the transmitting coil. C0 and L1 are in parallel resonance and then in series resonance with C0* to further boost the resonant voltage. After resonance, it is rectified by a rectifier bridge to convert the high - frequency changing magnetic energy into direct current, and R0 and R0* are used to limit this high voltage. In the circuit, D17 can prevent the high voltage from the back - end switching power supply from returning and forming a superposition when it is turned off, thus generating a higher voltage. D18 provides a voltage - current discharge circuit when the switch tube Q1 of the subsequent stage is turned off. The triple protection of the present invention is carried out simultaneously, and it notifies the background adapter that there is a short - circuit phenomenon, which needs to be processed, effectively reducing the losses to the device and the charging user during the charging process.

The invention relates to a magnetic resonance birdcage coil and magnetic resonance equipment. The magnetic resonance birdcage coil includes: a first end ring; a second end ring spaced apart from the first end ring in the axial direction; the first supporting legs are sequentially arranged between the first end ring and the second end ring at equal intervals in the circumferential direction around the axial direction, each first supporting leg is connected with the first end ring and the second end ring, each first supporting leg is connected with a first LC parallel resonance circuit in series, and the resonance frequency of the first LC parallel resonance circuit is a first frequency; the second supporting legs are sequentially arranged between the first end ring and the second end ring at equal intervals in the circumferential direction, each second supporting leg is connected with the first end ring and the second end ring, each second supporting leg is connected with a second LC parallel resonance circuit in series, and the resonance frequency of the second LC parallel resonance circuit is a second frequency different from the first frequency; the first end ring, the second leg, and the second end ring can resonate at a first frequency, and the first end ring, the first leg, and the second end ring can resonate at a second frequency.

The invention discloses a three-phase high-low frequency composite rotating magnetic field induction heating device and method. The device comprises a three-phase high-low frequency rotating magnetic field variable-frequency power supply device, a three-phase high-frequency coupling capacitor, a three-phase low-frequency coupling reactor and a three-phase inductor, the three-phase high-low frequency rotating magnetic field variable-frequency power supply device outputs three-phase high-low frequency composite alternating current with the angle difference of 120 degrees; the three-phase high-frequency frequency conversion series resonance circuit and the three-phase coupling capacitor are combined to form a three-phase high-frequency series resonance working mode; the parallel resonance circuit for the three-phase low-frequency frequency conversion and the three-phase coupling reactor form a three-phase low-frequency parallel resonance working mode; the three-phase inductor participates in high-frequency and low-frequency resonance at the same time to generate a high-low-frequency composite rotating magnetic field. Forward and reverse rotation of the magnetic field can be achieved, any high and low frequency combined rotating magnetic field induction heating is conducted on a heated metal object, and the induction heating quenching effect on the tooth top of a gear with the high frequency and the tooth groove with the low frequency is better than the using effect of a traditional single-frequency non-rotating magnetic field.

The application discloses a kind of low-loss on-chip transmission lines based on non-periodic composite left-right hand structure, it is related to radio frequency integrated circuit design technical field, including first radio frequency port, second radio frequency port, M series resonance unit and N parallel resonance unit, each series resonance unit includes series right-hand inductance, left-hand capacitance, each parallel resonance unit includes parallel left-hand inductance, right-hand capacitance;M series resonance unit is in turn connected in series, one end of N parallel resonance unit is in turn loaded between two series resonance units, and the other end of parallel resonance unit is grounded, first radio frequency port is loaded in the free end of first series resonance unit, and second radio frequency port is loaded in the free end of M series resonance unit.The application uses non-periodic lumped transmission line to avoid too large size;While maintaining low loss, echo loss in broadband is all better than 20dB.

The invention relates to a magnetic resonance birdcage coil and magnetic resonance equipment. The magnetic resonance birdcage coil includes: a first end ring; a second end ring spaced apart from the first end ring in the axial direction; the first supporting legs are sequentially arranged between the first end ring and the second end ring at equal intervals in the circumferential direction around the axial direction, each first supporting leg is connected with the first end ring and the second end ring, each first supporting leg is connected with a first LC parallel resonance circuit in series, and the resonance frequency of the first LC parallel resonance circuit is a first frequency; the second supporting legs are sequentially arranged between the first end ring and the second end ring at equal intervals in the circumferential direction, each second supporting leg is connected with the first end ring and the second end ring, each second supporting leg is connected with a second LC parallel resonance circuit in series, and the resonance frequency of the second LC parallel resonance circuit is a second frequency different from the first frequency; the first end ring, the second leg, and the second end ring can resonate at a first frequency, and the first end ring, the first leg, and the second end ring can resonate at a second frequency.

The invention relates to the technical field of power grid harmonic suppression, in particular to a fundamental-loss-free low-parallel-resonance band-pass filter which comprises a first single-tuned filter Hn1 and a second single-tuned filter Hn2 which are arranged in parallel, and the series resonance frequencies of the first single-tuned filter Hn1 and the second single-tuned filter Hn2 are different. A group of resistors R1 is bridged between the first single-tuned filter Hn1 and the second single-tuned filter Hn2; the first single-tuned filter Hn1 comprises a first capacitor C11, a second capacitor C12 and a first reactor L1, the first capacitor C11, the second capacitor C12 and the first reactor L1 are connected in series, the second single-tuned filter Hn2 comprises a third capacitor C2 and a second reactor L2, and the third capacitor C2 and the second reactor L2 are connected in series; according to the invention, the structure is simple, the cost is low, the resistor R1 has no fundamental wave loss, the energy conversion efficiency of the whole power system is improved, the loss of energy in the transmission and treatment process is reduced, and the energy-saving effect is good.

Example embodiments relate to pseudo-Doherty load modulated balanced amplifiers, PD-LMBAs. One example PD-LMBA is configured to operate in a given frequency band. The PD-LMBA includes a main splitter for splitting an input RF signal into a first signal and a second signal, a main amplifier for amplifying the first signal, a balanced amplifier for amplifying the second signal, and a phase offset unit. The balanced amplifier includes a splitter for splitting the second signal into a first part and a second part of the second signal, a first amplifier and a second amplifier for amplifying the first part of the second signal and the second part of the second signal, respectively, and a combiner. The phase offset unit includes at least one shunt series circuit connected to ground and at least one parallel resonance circuit arranged in between an input and an output of the phase offset unit.

The present application relates to the technical field of resonance analysis, and in particular to a method and device for evaluating effectiveness of a parallel resonance suppression scheme in a power system. In the present application, a local parallel resonance suppression evaluation index and a non-local parallel resonance suppression evaluation index are constructed, and corresponding feasible regions are constructed, so as to evaluate the parallel resonance suppression effect of a resonance suppression method access node and the effect of parallel resonance of surrounding other nodes. The present application solves the problem that the application scene of a resonance suppression method is limited and the parallel resonance scene is not compatible with the resonance suppression method.

An acoustic wave element having reflectors providing capacitance according to the present invention further improves skirt characteristics of the acoustic wave element steeply by configuring the reflector structure of the acoustic wave element such as a SAW resonator, a composite resonator, and DMS as a capacitive reflector structure so that the parallel resonance frequency can be shifted toward the series resonance frequency without additional capacitors connected to the acoustic wave element while maintaining the area.

The wireless communication device includes a rectangular base plate (10), a square opposing conductor plate (30), and a short-circuit section (40), configured as a zero-order resonant antenna that uses the electrostatic capacitance formed by the opposing conductor plate (30) and the base plate (10) and the inductance of the short-circuit section (40) to achieve LC parallel resonance. A power supply point (31) is formed at the edge of the opposing conductor plate (30). The opposing conductor plate (30) is positioned at a position offset by a predetermined end offset (De) from the end of the base plate (10) in the long side direction. The length of the base plate (10) in the long side direction is set to λ / 4×N+α. N is a natural number, and α is a predetermined value of 0.025λ or more and less than 0.225λ.

The application discloses a high-order mode coupler based on a double-inhibition structure of a transmission line model and a design method, and belongs to the accelerator physics and superconducting high-frequency technical field.The method comprises the following steps: determining a superconducting cavity base mode frequency, a high-order mode frequency band and an external quality factor Qe requirement; establishing an equivalent transmission line model comprising two parallel resonance base mode inhibition structures; optimizing a transmission curve through a normalized scattering matrix theory; converting the optimized transmission line model into a three-dimensional structure and further optimizing; modeling and calculating the external quality factor Qe in combination with the superconducting cavity; performing secondary electron multiplication effect simulation analysis; performing thermal load analysis by using an iterative process; and finally completing mechanical design.The application adopts the double-inhibition structure, greatly improves the base mode inhibition bandwidth, realizes deep inhibition of the base mode without pre-tuning, significantly reduces the superconducting module integration cost, improves the assembly efficiency and reduces the operation risk.

The invention belongs to the technical field of radio frequency receiving systems, and discloses a low-noise amplifier for broadband matching and gain planarization, a design method of the low-noise amplifier and a corresponding radio frequency receiving system. An LC parallel resonance network is used as a broadband input matching link unit, and a transformer load structure is used as a gain planarization unit; and an inductor in the LC parallel resonance network is used as a secondary winding of a transformer load in the transformer load structure. In a broadband input matching link accessed by an LC parallel resonator, an inductance element L of the resonator is regulated and controlled through a magnetic coupling coefficient and is synchronously used as a secondary winding of a gain flattening transformer to form a dual-function magnetic coupling structure, and the design breaks through a normal form that a traditional matching network and a gain network are independently designed, so that the design efficiency is improved. Collaborative optimization of impedance matching and gain flatness is realized, the layout area can be reduced, and cost reduction and efficiency improvement are realized. The method is suitable for optimizing the low-noise amplifier in the front-end architecture of the radio frequency receiving system.

The utility model relates to the technical field of ultrasonic waves, and discloses a driving circuit and an ultrasonic sensor, which comprise a switching module, a second inductor, an ultrasonic probe equivalent module and a controller. The switching module is electrically connected with the controller, the first end of the second inductor is connected with the switching module, and the second end of the second inductor is connected with the ultrasonic probe equivalent module. When an ultrasonic signal is transmitted, the controller controls the switching module to connect the first end of the second inductor with the alternating current power supply, so that the second inductor and the ultrasonic probe equivalent module form series resonance. When an ultrasonic signal is received, the controller controls the switching module to enable the first end of the second inductor to be grounded, so that the second inductor and the ultrasonic probe equivalent module form parallel resonance. While the miniaturization of the ultrasonic sensor is realized, the ultrasonic signals are transmitted under series resonance and received under parallel resonance through the switching module, the intensity of transmitting the ultrasonic signals is enhanced, and the sensitivity of receiving the ultrasonic signals is improved at the same time.

The invention discloses a resonance circuit, a power supply module and V2G charging equipment, and relates to the field of charge and discharge control, the resonance circuit is applied to a bidirectional DC-DC conversion circuit of the power supply module, when a power grid charges an electric load through the power supply module, parallel resonance is formed between a first inductor and a first capacitor, and between a second inductor and a second capacitor; the influence of electricity load change on the circuit stability is reduced, and the circuit stability is improved; when the electric load discharges to the power grid through the power supply module, series resonance is formed between the first inductor and the first capacitor and between the second inductor and the second capacitor, the frequency stability is high, the harmonic content of grid-connected current is low, and the quality of electric energy fed back to the power grid is high. According to the scheme, automatic switching between series resonance and parallel resonance can be achieved according to the current charging and discharging state, and bidirectional energy transmission between the electricity load and the power grid can be better achieved.

The utility model discloses a current sampling circuit, which comprises a direct-current power supply, a parallel resonance circuit, a linkage circuit, a rectifying circuit, a filter circuit, a driving end, a voltage output end and a sampling end, according to the utility model, the parasitic resistance when the first N-channel MOS tube is conducted is used for sampling, and the resistance value of the circuit is not additionally increased, so that the circuit is optimized, and the loss of the circuit and the heat generated when the circuit works are reduced; the current sampling circuit is applied to circuits needing an LC resonance circuit, such as wireless power supply, wireless charging, metal induction heating, metal detection, an LC booster circuit and the like, has great advantages, can increase the efficiency and the power of the circuit, and reduces the heat of the circuit during working.

The present disclosure provides a filter device capable of obtaining good characteristics even when an attenuation band based on parallel resonance is brought close to a passband based on series resonance. A filter device (100) according to the present disclosure is provided with: a first terminal (P1); a second terminal (P2); a first inductor (L1); and a series resonator (RS) disposed in the first path (TL1) among the first path (TL1) and the second path (TL2) provided in parallel. The series resonator (RS) includes: a second inductor (L2); a capacitor (C2) connected in series with the second inductor (L2); and a third inductor (L3) connected in series with the second inductor (L2) and the capacitor (C1). The magnetic coupling of the first inductor (L1) with the third inductor (L3) is weaker than the magnetic coupling of the first inductor (L1) with the second inductor (L2).

The invention discloses an FBAR structure with a multi-edge resonant structure and a manufacturing method. The FBAR structure comprises a core resonance structure and an edge structure, and the edge structure comprises a first edge resonance structure and a second edge resonance structure which are alternately distributed at the edge of the core resonance structure in the direction perpendicular to the thickness direction of the resonance area. And the first edge resonance structure, the second edge resonance structure and the core resonance structure adopt continuous piezoelectric layers. The bottom electrodes and the top electrodes of the first edge resonance structure and the second edge resonance structure are symmetrically arranged relative to the piezoelectric layer, and each of the bottom electrodes and the top electrodes is composed of two layers of electrodes made of different materials. By adjusting the thickness of each electrode, the series resonance frequencies of the core resonance structure, the first edge resonance structure and the second edge resonance structure are equal, the parallel resonance frequencies of the core resonance structure, the first edge resonance structure and the second edge resonance structure are equal, the offset of the parallel resonance point frequency is reduced, and the quality factor of the FBAR is improved.

A flexible annular current sensor based on an amorphous wire and a bandwidth compensation method thereof include a magnetic core, an induction coil, a low-pass filter, and a bandwidth compensation circuit; the induction coil is wound around the magnetic core and connected to the low-pass filter; the output end of the low-pass filter is connected to the bandwidth compensation circuit; the low-pass filter is used to integrate the induced electromotive force generated by the induction coil, and the bandwidth compensation circuit is used to perform bandwidth compensation and signal amplification on the filtered signal before outputting a voltage signal. By using ultrafine amorphous alloy wire as the magnetic core, the present invention overcomes the shortcomings of conventional current transformers with iron cores and Rogowski coils, such as large size, fixed shape, and low sensitivity, thereby significantly improving the flexibility and performance of the current transformer. The bandwidth compensation circuit based on parallel resonance greatly broadens the bandwidth of the current transformer, and the bandwidth compensation circuit has the advantages of simple structure, low cost, and stable performance.