Integrated surface acoustic wave wireless pressure sensor applied to TPMS

Abstract

The invention relates to an integrated surface acoustic wave wireless pressure sensor applied to a TPMS, comprising two SAW reflection delay lines which are encapsulated for integration with a JSR membrane by a nickel conducting cylinder and a conducting adhesive, and a matched network connected with a wireless antenna, wherein, the first SAW reflection delay line comprises a single-phase unidirectional energy converter for controlling electrode width, and 3 short-circuit gate reflectors applied to pressure detection; and the second SAW reflection delay line comprises 11 short-circuit gate reflectors, wherein, 8 reflector are used for 8-bit electronic tags, and the other 3 reflectors are used for temperature detection. In the sensor, an EWC / SPUDT receives an electromagnetic wave signal from a wireless reading unit by the wireless antenna and transforms the signal into an SAW signal which is propagated along the surface of a piezoelectric substrate and is respectively reflected by the reflectors, the reflected acoustic wave is retransformed into the electromagnetic wave signal by the EWC / SPUDT and is returned to the wireless reading unit by the wireless antenna, and finally temperature and pressure detection in a tire is realized at the same time by evaluation of a phase change of time-domain response via a signal processing method.

Description

technical field [0001] The present invention relates to a wireless pressure sensor, in particular to a surface acoustic wave (Surface acoustic wave: SAW) integrated temperature detection and electronic label pressure sensor for pressure monitoring of a tire pressure monitoring system (TPMS). Background technique [0002] In recent years, safety has been the main driving force for the development of automotive tire pressure monitoring systems (TPMS), because many traffic accidents are related to tires, so TPMS is expected to become the fastest growing automotive electronics application. According to statistics, abnormal tire pressure will destroy the stability of the car and affect the driving and braking of the car, resulting in hundreds of thousands of traffic accidents every year. In addition, about 20% of the tires are still under-inflated at 40%, which not only significantly reduces the life of the tires, but also increases fuel consumption. According to Goodyear, every...

AI Technical Summary

Problems solved by technology

The wireless pressure sensor using the SAW reflective delay line applied to the TPMS in the prior art has a single function, and cannot realize the simultaneous detection of parameters such as the temperature and pressure inside the tire.

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