A 3-Bit Passive Wireless Strain Sensor Design Based on Backscattering Principle

In recent years, research on structural health monitoring (SHM) has gradually emerged, and real-time monitoring of structures can reasonably avoid and reduce the loss of safety. Fine strain detection can be performed by constructing a strain sensor based on a microstrip antenna. In order to explore the design and working principle of strain sensor, this paper proposes a passive wireless strain sensor. It consists of three tip loaded dipole resonators and a circular microstrip patch antenna (CMPA) resonator. The radar cross section of the sensor was obtained by HFSS simulation, and the resonant frequency from the 3-bit dipole resonator and the resonant frequency of CMPA were observed. Subsequent production of the physical object, using the USRP for testing, optimization of the design based on the test results, and error analysis.