Floer Cecile, Hage-Ali Sami, Nicolay Pascal, Chambon Hugo, Zhgoon Sergei, Shvetsov Alexander, Streque Jeremy, M'Jahed Hamid, Elmazria Omar
IEEE Trans Ultrason Ferroelectr Freq Control. 2020 Jun;67(6):1267-1274. doi: 10.1109/TUFFC.2019.2943310. Epub 2019 Sep 23.
Remote interrogation of surface acoustic wave identification tag (ID-tags) imposes a high signal amplitude which is related to a high coupling coefficient value ( K ) and low propagation losses ( α ). In this article, we propose and discuss an alternative configuration to the standard one. Here, we replaced the conventional configuration, i.e., one interdigital transducer (IDT) and several reflectors, by a series of electrically connected IDTs. The goal is to increase the amplitude of the detected signal using direct transmission between IDTs instead of the reflection from passive reflectors. This concept can, therefore, increase the interrogation scope of ID-tags made on a conventional substrate with high K value. Moreover, it can also be extended to suitable substrates for harsh environments, such as high-temperature environments: the materials used exhibit limited performances (low K value and relatively high propagation losses) and are, therefore, rarely used for identification applications. The concept was first tested and validated using the lithium niobate 128° Y-X cut substrate, which is commonly used in ID-tags. A good agreement between experimental and numerical results was obtained for the promising concept of connected IDTs. The interesting features of the structure were also validated using a langasite substrate, which is well-known to operate at very high temperatures. Performances of both substrates (lithium niobate and langasite) were tested with an in situ RF characterization up to 600 °C. Unexpected results regarding the resilience of devices based on congruent lithium niobate were obtained.
对表面声波识别标签（ID标签）进行远程询问时，需要施加高信号幅度，这与高耦合系数值（K）和低传播损耗（α）相关。在本文中，我们提出并讨论了一种与标准配置不同的配置。在这里，我们用一系列电连接的叉指换能器（IDT）取代了传统配置，即一个叉指换能器（IDT）和几个反射器。目标是通过IDT之间的直接传输而不是无源反射器的反射来增加检测信号的幅度。因此，这一概念可以扩大在具有高K值的传统基板上制作的ID标签的询问范围。此外，它还可以扩展到适用于恶劣环境的基板，如高温环境：所使用的材料性能有限（低K值和相对较高的传播损耗），因此很少用于识别应用。该概念首先使用ID标签中常用的128°Y-X切割铌酸锂基板进行了测试和验证。对于连接IDT这一有前景的概念，实验结果与数值结果取得了良好的一致性。还使用了一种众所周知可在非常高的温度下工作的硅酸镧镓基板对该结构的有趣特性进行了验证。两种基板（铌酸锂和硅酸镧镓）的性能都在高达600°C的原位射频表征下进行了测试。基于同成分铌酸锂的器件的弹性得到了意想不到的结果。
