Simulation and Experimental Validation of Electromagnetic Noise from a PFN-Marx Generator in High-Power Microwave Systems

Electromagnetic (EM) noise from a gigawatt-level pulse-forming-network (PFN) Marx generator in a high-power microwave (HPM) system is investigated through both simulation and experiment. Using CST Studio Suite, EM noise was analyzed in terms of emission locations and spectral characteristics. The results show that noise is primarily generated within the PFN-Marx generator and transmission line, and radiates externally through insulator plates. Frequency spectrum analysis indicates distinct peaks below 1.5 GHz, with field strengths on the order of tens of V/m at a distance of 1 m. Experimental measurements conducted on the same model exhibited good agreement with the CST simulations, confirming the reliability of the modeling approach. In addition, simple metallic shields applied to the model suppressed the dominant low-frequency peaks, leaving weaker high-frequency components around 12.8 GHz with magnitudes of several tens of mV/m as residual emission. This work provides one of the few experimental validations of CST-based EM noise modeling for PFN-Marx generators and demonstrates that a validated, geometry-based simulation approach can serve as a practical tool for evaluating electromagnetic interference characteristics and shielding effectiveness in HPM system design.