Research On High Dynamic Occultation Signal Simulator

The occultation detection system needs to measure the phase and amplitude of the occultation signal with high dynamic change high precisely,so the technology of high dynamic,high precision occultation signal simulation is one of the key technologies of the occultation exploration system,which has very important scientific significance and engineering application value for the occultation detection system design,development and test.So far,there is no satellite signal simulator specifically used for the occultation exploration system neither at home nor abroad,let alone mature products.The specific occultation detection system of the satellite signal simulator is first designed and successfully developed.With the use of FPGA embedded control,based on software radio and frequency synthesis technology,the high dynamic,low phase noise,and low stray occultation signal simulator is achieved.Through the actual test,the high dynamic occultation signal simulator has reached the domestic advanced level.The output spectrum of the simulator ranges from 1.7GHz to 1.8GHz.Within the 1MHz bandwidth,phase noise of the system output signal is less than-74.61dBc/Hz@10Hz,and stray signal is less than-73.82dBc/Hz@12.80 Hz.The frequency resolution is 135 pHz,and the frequency changing rate is 2.5×10-12Hz/s~6.67×108Hz/s.