口径辐射场的时域分析

Time Domain Analysis of Aperture Radiation

鉴于瞬态电磁脉冲辐射研究的重要性，天线的时城辐射特性是当前备受关注的重要问题，然而口径辐射场的完整时城解尚未有报道。本文采用时城法利用场等效原理分析电磁脉冲辐射场，得到时域中口径辐射场的解析解，得出的公式对近场、远场都适用。利用这一结果，对高斯脉冲辐射场的时域规律进行了计算分析。计算结果表明近区电场随距离呈任于1／衰减，这与电磁导弹效应相一致。所得公式为进一步研究脉冲天线辐射、散射等问题提供了一种方法。

In view of the importance of radiation research on transient electromagnetic pulse, the radiant property of antenna's time domain is an important ape to which close attention has been paid nowadays. However, the whole time domain solution of the aperture radiant field has not yet been reported , to authors' knowledge. For the research of the transient electromagnetic pulse radiation of aperture, a time domain method is used on the basis of field equivalence principle in this paper.The time domain soution of the aperture radiation field is proposed, which is suitable for near field as well as far field. On this basis, the time variation of the radiation field of a Gaussian pulse is shown with further numerical calculation- The numerical results show that the decaying rate of electric fieldis slower than the inverse law in near field, which resembles tke electromagnetic missile effect. The solution is helpful to the further investigation of pulse antenna radiation and electromagnetic pulse scattering.