| Passive wireless sensor technology is one of important aspects for modern sensor techology. In the inflammable and explosive measurement, high temperature, low temperature, high voltage, powerful electromagnetic field and some other special application, passive wireless surface acoustic wave(SAW) sensor has more advantages than other sensors. It can constitute not only sensor array, but also encoder and decoder. It can be used for target recognition and smart traffic system. Therefore, the study of passive wireless sensor has scientific and engineering significance.The studies on the passive wireless sensors mainly focus on delay SAW sensors and ID-tag. Because the quality of the delay SAW device is very low, it only can be used for detecting in short distance. In this thesis, the principle, signal processing and instrument system of the resonator and the delay-resonator passive wireless SAW sensors are studied, and some valuable results have been obtained. The main work is provided as follows:1. A new delay-resonator passive wireless SAW sensor is proposed. It has both delay line and resonator advantages, so it can be used in longer distance. Its response characteristic for impulse signal is deduced. And the experiment system is constructed.2. Responses of one-port SAW resonator for impulse signal, sinusoidal burst signal and steady-state are deduced. Principle and equivalent circuit of one-port SAW sensor are analysed.3. According to software radio method, a passive wireless SAW sensor transceiver system by using the NI virtual instrument, the personal computer, the universal circuits and the module is realized. A signal generator of high-resolution, automatic search is accomplished by using the direct digital synthesis (DDS). The nolinear effect of the transmiting-receiving switch is eliminated. In processing circuit, the programmable gain amplifier (PGA) is used for different signal amplitudes. The match network in antenna is analysed. 4 meter detecting distance is obtained in 15 cm dipole antenna.4. The characteristic of the signal and the main noises is analysed. A new frequency evaluation method is proposed. The signal/noise ratio can be improved by using this method. And many experiments have shown that this method is correct.5. A concept of self-generating of electromagnetic energy in SAW device is proposed. Its principle is analysed. Its structure and system are designed. According to piezoelectric effects, the principle and the structure of self-generating of mechanic energy are also introduced. This thesis analyses the properties of self-generating sensors and shows that the detecting distance will be improved greatly. So it can be used for more application fields. Besides, a micro-manufacturing procedure of quartz is introduced. The micro three-dimensional structure with high width-height ratio can be obtained by this procedure. Therefore, the thermal stress between sensor and exterior structure can be eliminated by using integration technology.6. The SAW wave functions in isotropic and anisotropic medium are analysed. The acoustic radiation module of function in the interdigital transducer (IDT) is introduced. Its principle and characteristic are analyzed. The module of cross field and longitudinal field is set up. The network equation, input admittance and radiation characteristic are analyzed.7. The effects of pressure, vibration, mass loading, conductivity and other parameters in applications of passive wireless SAW temperature sensor are analyzed. The prevention of the effects is discussed. In applications of frequency division multiplexing (FDM) and encoding passive wireless sensor array, the sensing principle and the structure are analyzed.8. The two modularized and universal passive wireless SAW sensor experiment systems are developed by using NI6115 and NI5102 virtual instruments. The principle research and temperature experiment analyses in the virtual instrument experiment system are accomplished. The error analysis is finished. The experiment system is optimized. Th...
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