A composite coded saw temperature and pressure integrated sensor and its preparation method

Abstract

The invention discloses a compound encoding type SAW (Surface Acoustic Wave) temperature and pressure integration sensor and a preparation method thereof. The sensor comprises a substrate and a piezoelectric material arranged on the surface of the substrate, wherein the piezoelectric material is provided with a SAW resonator, and a sealing cavity is arranged in the substrate. The SAW resonator deposited on the piezoelectric material is used for changing the effect of resonant frequency along with an external temperature to measure the temperature, and the SAW resonator which grows in an emptycavity is used for changing the effect of resonant frequency along with external pressure to measure pressure. The compound encoding type SAW temperature and pressure integration sensor does not needto be driven by internally added energy and does not need to transmit a signal by a conductor, and therefore, the sensor has the characteristics that the sensor is wireless and passive and can work inextremely severe environments, including high temperature, high pressure, sealing space and the like. A time encoding technology is used, a radio frequency signal can be inquired to easily measure the resonant frequency of two different SAW resonators without causing aliasing.

Description

technical field [0001] The invention belongs to the technical field of sensors, and in particular relates to a composite coded SAW temperature and pressure integrated sensor and a preparation method thereof. Background technique [0002] In industrial production, electronic products, and safety testing, sensors have been used more and more, among which sensors for measuring temperature and pressure are used particularly frequently. Traditional temperature sensors or pressure sensors need to use wires to connect the signal receiving device to the sensor, and some sensors also need an external drive source when used. In some occasions that require signal receiving equipment to be isolated from the sensor, such as tire temperature and pressure monitoring in a moving car, this type of sensor cannot play a role. And under the trend that miniaturization and low power consumption gradually become the design theme of electronic products, it is not a good choice to use such sensors ...

AI Technical Summary

Problems solved by technology

[0004] The existing technology has the following defects: the traditional sensor for measuring the pressure by measuring the deformation of the cavity, the cavity is bonded or welded by two concave materials corresponding to the upper and lower sides, and there are disadvantages in terms of air tightness and mechanical strength. natural defect

The temperature sensor and pressure sensor in the prior art use wires to transmit the collected signals, which is difficult to integrate with the processing unit, consumes energy, and will be affected or even unable to work in some extremely harsh environments.

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