Further modification of the radar range equation due to slow decay effect in electromagnetic radiation

摘要

Conventional radar range equations based on the distance inverse-square spreading of energy should be further modified when taking into account a significant energy slow decay effect of the radiation. It is shown that the modification due to asymptotical energy slow decay effect in ultrawide-band (UWB) radiation can be neglected to certain extent since it is essentially equivalent to a continuous wave (CW) modification for a specified radiation frequency defined as the "characteristic frequency". For a wide-spectrum short-pulse (SP) radar, notable modification due to significantly enhanced slow decay effect should be taken into account. Generally, a reduction of the radar performance compared to that calculated for the inverse-square spreading of energy is obtained. The prospect of improving the radar range performance with an electromagnetic missile is greatly reduced by the harsh excitation needed to excite it. Moreover, the modified radar equation contains time-space source parameters such as the signal waveform and the current distribution of the antenna. Thus, an SP radar has a specialized radar equation and due attention should be paid to source parameters in the design of such a radar.