SAWR dynamic strain sensor detection mechanism for high-temperature harsh-environment wireless applications

High-temperature harsh-environment dynamic strain sensors are needed in multiple contemporary industrial and defense monitoring and control applications, in particular in power plants, metal manufacturing, and aerospace industries. Surface acoustic wave resonator (SAWR) technology stands out as an ideal sensor platform due to attractive technological features such as: small size, capability of wireless operation, battery-free operation, and resilience to high-temperatures. The SAWR dynamic strain sensor detection mechanism discussed in this paper reveals that both frequency and magnitude of the dynamic strain signal can be directly measured. Moreover, in-phase and quadrature component analyses of the measured free-resonating SAWR signal exposed to the dynamic strain perturbation show that both frequency and amplitude modulation are present. The results confirm the appropriateness of the SAWR sensor to detect both the frequency and magnitude of dynamic strain, making this technology very attractive for dynamic strain sensor applications, including situations that require wireless operation in high-temperature harsh-environments.