Resarch And Design Of Spectrum Analyzer Based On Virtual Instrument

Spectrum measurement plays an important role in the field of electronic measurement, as it is a significant method to understand and evaluate the operation objective in this field. Spectrum analyzer is a special instrument for spectrum measurement. In recent years, along with the great development of devices and technique, instrument for spectrum analyzing achieved great improvement.Two methods of how to analyze the spectrum, phase sensitive detection and zero-crossing algorithm, are discussed in this paper. Combined with the technology of Virtual Instrument, the hardware circuit of impedance spectrum analyzer with the nuclear of AD5933 is built and relative programs are written. Some samples are measured by this system. Through the analysis of test data, causes of test error are discussed, and suggestions of how to improve the system is presented.In addition, the research of zero-crossing algorithm is done in this paper. The hardware circuit of zero-crossing algorithm with nuclear of DDS chip AD9956 and ADC chip AD9248 is built; selection of chips in the circuit is also an important part of the research.The analysis of the possible factors resulted in the errors is presented and the optimal design project is offered. This task makes a preliminary study of the spectrum analysis in theory and practice. The possible problems which may presents in the development of an impedance spectrum analyzer are discussed so as to make a good foundation for the development of a better spectrum analyzer in the future.