Frequency Selective Surfaces for Pulsed High-Power Microwave Applications

We examine the peak power handling capability of a class of miniaturized-element frequency selective surfaces composed entirely of non-resonant constituting elements. The effects of various design parameters on the peak power handling capability of these structures are investigated using electromagnetic simulations and methods for increasing their peak power handling capability are proposed. These methods are used to design a high-power microwave (HPM) frequency selective surface (FSS), which is expected to be capable of handling extremely high peak power levels. The power handling capabilities of these devices are also experimentally investigated using an HPM source with a frequency of 9.382 GHz, a peak power of 25 kW, and a pulse length of 1 μs. Unit cells of various FSSs under investigation are placed in a waveguide and excited with pulses with variable power levels. The time-domain reflection and transmission coefficients of each device is measured at various power levels and the power level at which the device breaks down is determined. The results of these experimental investigations follow the same trend observed in the simulations. Additionally, our experiments demonstrate that the HPM FSSs developed in this work are indeed capable of handling extremely high peak power levels.