Design For The Signal Detection System Of The SiCN Temperature Sensor Based On LabVIEW

The SiCN temperature sensor is a passive wireless sensor cavity, which uses SiCN ceramic as dielectric resonator, the material has some advantages such as thermal shock,corrosion and oxidation resistance, etc. In this paper, the temperature measurement range of the SiCN temperature sensor is 0?300 ?, through the analysis of resonator sensor modeling,using the theory of weak-disturbance modifying measuring, and combined with the NI Company of the PXIe-5644 R vector signal transceiver(VST), circulator, waveguide and high-frequency devices, the paper design a SiCN temperature sensor detection system based on LabVIEW.Through the theoretical analysis and the sensor research, this paper use the sweep method to detect the sensor. Using LabVIEW PC to control VST to generate a frequency sweep signal, through the circulator and waveguide converter transmit RF signals to the SiCN sensor in a wireless way. After a certain period of response, PC acquires, displays processing analysis and storages the sensor signal, so as to complete the sensor characteristics are measured.The system software consists of source modules, signal acquisition module, signal processing module, display and storage module. According to the measuring range of the sensor, and through the control module of PC software, Users can set the appropriate parameters to achieve the sensor measurement.Echo signal analysis and processing technology are the key issue of this paper.Considering the echo signal collected by VST contains lots of noise signal, on the basis of common signal processing theory brief analysis, this paper use conventional digital filtering algorithm and wavelet thresholding method to reduce the noise signal and validate analysis the signal processing method by LabVIEW. In the extraction of echo signal of resonant frequency, the first two of the 200 data in the neighborhood(removing singular point and fitting), through the relevant algorithm to calculate the resonant frequency of the sensor values. Finally, calculating the resonant frequency of the sensor by the relevant algorithm.The results indicated that the resonance frequency of the sensor measurement error is less than 30 k Hz in the fixed conditions of temperature, and the response time is about 15 us. While in the 50 to 300 ? temperature experiment conditions, the sensitivity of the sensor is about49.96KHz/?.