Modeling and simulation of the radiation characteristics of IRA

In this paper, we made research on the radiation characteristics of IRA with analytical and simulation methods. According to the research results, IRAs exhibit excellent characteristic, as small VSWR at low frequency range, short oscillation time of radiation waveform, narrow main beam, high gain and ultra wide-band. Typical radiation pulse of IRA consists of two parts, namely, the pre-pulse, which share the same shape as the excitation voltage source and is generated by the backward radiation of feed arms, and the main pulse, whose time-domain shape is the differentiation of the excitation voltage. As the volume of IRA decreases, the amplitude of pre-pulse remains the same, while that of the main pluse decreases by the same proportion.