Surface acoustic wave pressure sensor based on loss detection

Abstract

The invention relates to a surface acoustic wave pressure sensor based on loss detection. The surface acoustic wave pressure sensor comprises a substrate, an interdigital transducer, a first metal reflective grating array and a second metal reflective grating array. The interdigital transducer is arranged at the center of the substrate; the first metal reflective grating array is arranged at one side of the interdigital transducer; and the second metal reflective grating array is arranged at the other side of the interdigital transducer. A gap is formed between the interdigital transducer andthe first metal reflective grating array; and a gap is formed between the interdigital transducer and the second metal reflective grating array. Output leads are connected to bus bars at the two endsof the interdigital transducer. According to the invention, the pressure detection method of the surface acoustic wave pressure sensor is based on the loss change of the device; no pressure referencecavity needs to be prepared during the sensor implementation process; the process difficulty is reduced substantially; the yield is high; and mass production of semiconductor processing is realized conveniently.

Description

technical field [0001] The invention relates to a surface acoustic wave pressure sensor based on loss detection, which belongs to the field of sensor design. Background technique [0002] Pressure sensors are the most widely used of all types of sensors. According to the principle of pressure measurement and different manufacturing processes, pressure sensors can be divided into piezoresistive, capacitive and optical fiber types. Their dimensions, accuracy and scope of application Each is different. Among them, as a new type of sensor, the surface acoustic wave pressure sensor has attracted widespread attention due to its small size, low cost, high stability, strong anti-electromagnetic interference ability, and wireless passive work. [0003] At present, the detection method of the surface acoustic wave pressure sensor is often based on the change of the acoustic wave propagation phase, time or velocity, and the pressure reference cavity is formed between the pressure sens...

AI Technical Summary

Problems solved by technology

However, limited by the characteristics of the packaging process, the packaging of the existing reference cavity is difficult, the consistency is poor, and the uniformity is not good, and the performance of the same batch of sensors varies greatly.

Especially the point pressure packaging structure, its process is complicated, and the yield rate of the sensor is low

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