Precision determining method for surface acoustic wave radio frequency label echo time delay

Abstract

Disclosed is an accurate confirming method of the back wave time delay of an acoustic surface wave radio-frequency tag, the steps of the method comprise setting a parameter delta n, limiting the possible time delay of each reflected pulse under the standard temperature, only permitting the possible time delay to exist in a series of extremely small range of delay time decided by the delta n, auxiliary confirming the integer number of the carrier cycle in pulse time delay by measuring group time delay, enabling the uncertainty of the integer part of the back wave phase time delay to be limited in a certain range, and utilizing the incidence relation of a preset permission time delay range and a back wave phase in the range to confirm the integer part of the time delay in the certain range, thereby accurately obtaining the back wave time delay. When measuring the back wave time delay under an unknown temperature, the designed time delay under the standard temperature can be obtained after measuring a temperature time delay coefficient through the phase difference of 1-2 reflecting grating intervals of the known time delay under the standard temperature. Under the condition of meeting the reliability of the system, the method of the invention can be utilized to design the largest different code quantity on the acoustic surface wave radio-frequency tag of which the substrate length is limited.

Description

Technical field: [0001] This patent relates to coded surface acoustic wave (SAW) radio frequency tag technology, specifically, to a method for accurately determining echo time delay by using carrier phase information combined with group delay measurement, including necessary Temperature compensation. technical background: [0002] In the 1990s, there was an upsurge in research and development and use of radio frequency tags (RFID) in scientific research institutions and business circles. Surface acoustic wave (SAW) radio frequency tags belong to one of the classifications of radio frequency identification technology, and are a new type of non-contact automatic identification technology that is different from IC chip identification, passive and chipless. It is a new achievement of the system applying modern electronics, acoustics, semiconductor plane technology, radar and signal processing technology. The main features of the radio frequency tag realized by SAW technology a...

AI Technical Summary

Problems solved by technology

(2) No specific implementation method for delay determination is proposed

If the parameter is too large, the different code capacity of the same system will be greatly reduced, reducing the superiority of this method; if the parameter is too small, it will cause the non-uniqueness of the determined delay integer value, resulting in the loss of system reliability.

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