一、引言自从麦克斯韦建立电磁理论、赫兹发现电磁波百余年来,电磁能得到了充分的利用。尤其在科学发达的今天,广播、电视、通信、导航、遥测遥控及计算机等领域得到了迅速的发展,给人类创造了巨大的物质财富。然而,伴随电磁能的利用,也带来了电磁干扰的产生。无用的电磁场,通? I. INTRODUCTION Since Maxwell established electromagnetic theory, Hertz discovered that the electromagnetic energy has been fully utilized for over a hundred years. Especially in today’s highly developed science, rapid development has been made in the fields of radio, television, communications, navigation, telemetry and computer and so on. Huge material wealth has been created for mankind. However, along with the utilization of electromagnetic energy, electromagnetic interference has also been brought about. Useless electromagnetic field, pass?