Full-digital Simulator Of High-order Passive Intermodulation And Its Implementation

With the development of high power multi carrier satellite,passive intermodulation problems in the transceiver antenna system has become more and more serious,has become an important factor restricting the development of the satellite.After calculation,fall into the satellite receiver for high order modulation signal of passive intermodulation products.Therefore,the simulation and analysis of high order passive intermodulation signal is the focus of future research.The passive intermodulation behavior model based on,of modulated signal of passive intermodulation products carries on the preliminary analysis,simulation of arbitrary order passive intermodulation signal,and digital simulation based on FPGA platform.After verification,the passive intermodulation spectrum signal simulator are consistent with the measured spectrum,indicating the correctness of the program.Basic principle of nonlinear systems is proposed in this paper,analysis of the frequency characteristics of passive intermodulation interference of frequency distribution,and the Hammerstein series model of passive intermodulation of in-depth analysis.Finally,the analysis of BPSK and QPSK signals of passive intermodulation product model in time domain,and the model was modified using the measured data.Finally the performance of the two algorithms of analysis and simulation,results show that,the two algorithms in low signal-to-noise ratio environment have excellent performance.At last,the paper introduces the hardware specific implementation process,on the front of the principle of the hardware verification,gives the hardware implementation scheme,and a detailed analysis of the implementation process of the digital system module,according to the theory of passive intermodulation model design a platform of arbitrary order PIM signal produced by digital method.Finally,the system were test,results show that,the hardware implementation results meet the design requirements.