Numerical analysis on the influences of gas switch on the output characteristics of a linear switch array pulsed modulator

A linear switch array pulsed modulator (LSAPM) which can generate a central frequency oscillation pulse was designed. The circuit model of the LSAPM was established, and the influences of parameters of gas spark switch including electrodes capacitance, spark inductance, spark resistance and gas switch stages on the output waveform and amplitude-frequency characteristics were investigated. The results show that, the LSAPM generates a pulse with the center frequency of 1.2GHz electromagnetic pulse at electrical length of 0.33ns perstage transmission line, electrode capacitance of 6pF and transmission line impedance of 32Ω. The amplitude-frequency characteristics can be optimized by adjusting electrode capacitance and spark inductance. The amplitude of output pulse increases with the decreasing of spark resistance. Moreover, both the amplitude at central frequency and oscillation duration time increase with the increasing of the number of switch stage.