Surface acoustic wave sensor with low loss and high temperature stability

Abstract

The invention provides a surface acoustic wave sensor with low loss and high temperature stability, which comprises a piezoelectric substrate, an input interdigital transducer and an output interdigital transducer which are deposited on the piezoelectric substrate and sensitive membranes covered on the piezoelectric substrate, the input interdigital transducer and the output interdigital transducer. The piezoelectric substrate is made of crystal materials with high electromechanical coupling factor and high temperature stability, and the piezoelectric substrate adopts LGS, LGT, LGN, gallium phosphate, Sr3TaGa3Si2O14, Sr3NbGa3Si2O14, Ca3TaGa3Si2O14, Ca3NbGa3Si2O14, Sr3Ga2Ge4O14 and lithium tetraborate. The input interdigital transducer excites and spreads acoustic waves in the piezoelectricsubstrate, the output interdigital transducer is used for receiving the acoustic waves, when a loaded object to be tested reacts with the sensitive membranes, the features of the acoustic waves are changed, and a conclusion of the features of the object to be tested is obtained by detecting the changes. The surface acoustic wave sensor improves the performances of the sensor on the structural aspect and realizes the practical surface acoustic wave sensor with low loss and high temperature stability.

Description

technical field [0001] The invention relates to a novel surface acoustic wave sensor with low loss and high temperature stability, in particular to a sensor using gallium lanthanum silicate (La 3 Ga 5 SiO 4 or Langasite), gallium lanthanum tantalate (La 3 Ga 0.5 Ta 0.5 o 14 or Langanite), gallium lanthanum niobate (La 3 Ga 5.5 Nb 0.5 o 14 or Langatate), gallium phosphate (GaPO 4 ), Sr 3 TaGa 3 Si 2 o 14 (STGS), Sr 3 NbGa 3 the si 2 o 14 (SNGS), Ca 3 TaGa 3 Si 2 o 14 (CTGS), Ca 3 NbGa 3 Si 2 o 14 (CNGS) and Sr 3 Ga 2 Ge 4 o 14 (SGG) and lithium tetraborate (Lithium tetraborate) as a new surface acoustic wave sensor substrate. Background technique [0002] In recent years, with the rapid development of aerospace, mobile communication, information sensing and other technologies, the requirements for surface acoustic wave (SAW) devices are getting higher and higher. As the core unit of SAW devices, the piezoelectric substrate plays a decisive role ...

AI Technical Summary

Problems solved by technology

[0008] The object of the present invention is to provide a novel surface acoustic wave sensor with high electromechanical coupling coefficient and high temperature stability with low loss and high temperature stability, which can overcome the low electromechanical coupling coefficient of existing quartz substrates and the problems of lithium niobate and The defect of poor temperature stability of the lithium tantalate substrate improves the performance of the sensor from the structural aspect, and realizes a practical surface acoustic wave sensor with low loss and high temperature stability

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