Thin film type structural magnetofluid-sonic surface wave integrated magnetic transducer

Abstract

The invention discloses a sound surface wave integrated magnetic sensor for a magnetic fluid with a thin film structure, which comprises a piezoelectric substrate, two interdigital transducers (IDT), a magnetic fluid thin film and two sets of antennae for receiving and transmitting magnetic wave signals; the two interdigital transducers (IDT) are positioned at two ends of the substrate respectively; the magnetic fluid thin film is filled in a shallow groove between the two interdigital transducers on the surface of the sensor and encapsulates the groove; two sets of the antennae for receiving and transmitting the magnetic wave signals are connected to omnibus bars of the two IDTs respectively; the sensor can realize passive wireless high-precision real-time magnetic intensity measurement, and receive a radio frequency signal by the antennae, excite a horizontal shearing sound surface wave on the IDTs; the zero lagging response of the magnetic fluid on the change of an outer magnetic field instantaneously changes the delaying time of the sound surface wave delaying line, namely the viscosity change of the magnetic fluid changes the wave speed of the sound wave, converts the sound surface wave subjected to sound speed change into a magnetic wave by the IDTs and transmits the magnetic wave by the antennae. According to the corresponding relation of the delaying time and the magnetic filed intensity change, the magnetic filed change can be accurately measured.

Description

technical field [0001] The invention relates to the field of production and application of a magnetic sensor, in particular to a magnetic fluid-surface acoustic wave integrated magnetic sensor with a thin-film structure. Background technique [0002] At present, with the rapid development of information industry, industrial automation, power electronics technology, transportation, medical equipment, office automation, household appliances, etc. and the popularization of electronic computer applications, a large number of sensors are required to convert the measured non-electrical parameters into computer-compatible This provides an opportunity for the rapid development of magnetic sensors, forming a considerable magnetic sensor industry. [0003] Traditional magnetic sensors are mostly magnetoresistors or giant magnetoresistances based on the magnetoresistance effect, which are processed to measure magnetic fields. Including the earliest Hall effect device based on Hall eff...

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Problems solved by technology

[0005] The range of magnetic field strength measured by the above-mentioned various magnetic sensors is limited by their respective principles. Even the magnetic sensors made of giant magnetostrictive materials are not high enough in response sensitivity and real-time performance is not good enough, and the above-mentioned magnetic sensors are not easy to realize passive wireless signals. Excitation and transceiver control

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