The Sun And Interplanetary Radio Spectrum Analyzer Developed

The operating principle and basic structure of radio spectrum analyzer are introduced, the operating principles for each part are analyzed, and the main technical specifications (sensitivity, dynamic range, calibration method for radio spectrum analyzer) of spectrum analyzer are presented in detail. The design is described in detail and some experimental data are also given out.The radio spectrum analyzer introduced in this paper is different from the common spectrum analyzer. It has no requirement for display, but should fulfill the extreme requirements for sensitivity, dynamic range, data collecting velocity, etc.. To achieve high sensitivity, the pre-amplifier with very low noise figure is adopted in the design, and reliable grounding and shielding processing are performed. Each part of the signal channel is designed with efficient dynamic range. The radio spectrum analyzer adopts the superheterodyne receiving mode. To achieve higher frequency-scan speed, the direct frequency synthesis technique is utilized, and the obtained controllable frequency-scan frequency source is used as local oscillator. The square-law detector is used for detection, because only when the square-law detector is used, the linear relationship between the received record and the radio flow density exists. Through reasonable circuit design and test, expected results are obtained.