Research on the Quadrature Demodulation-Based Quartz Crystal Microbalance Implementation Method

In order to overcome the shortcomings of traditional quartz crystal microbalance (QCM) network measuring method, such as high requirements for hardware devices, low measurement speed and high challenge to curve fitting, a method based on the Quadrature Demodulation was proposed to design a rapid and accurate measuring system for QCM parameters, which mainly took the advantages of Quadrature Demodulation to remove the intermediate frequency component while reserve the low frequency component. Furthermore, the effectiveness of this method was proved by contrasting the Matlab simulation results with the actual measurement results based on the modified measuring system, which indicated that the frequency resolution could reach 0.1Hz with high testing speed of 0.02s per cycle, the relative deviations of resonance frequencies were less than 0.01% and the deviation of the differences between series and parallel resonant frequency points was 0.38%.