电磁波ＣＴ场源特性直接影响到穿透深度、成像分辨率的效果。设计了一种ＬＲＣ电路控制的瞬变垂直磁偶极子场源， 该场源可通过线路中的电阻调节其振荡频率和衰减速率， 以获取能量高、穿透能力强的时域电磁波信号。理论分析与计算结果表明， 接收波形随距离衰减的程度远大于随电阻率减小而衰减的程度； 当观测距离大到一定程度或电阻率小到一定值时， 记录的时域波形近似为源信号的包络线， 相对简单，易于测量其峰值旅行时， 从而达到高分辨率成像目的。 Electromagnetic wave CT field source characteristics directly affect the depth of penetration, imaging resolution effect. A transient vertical magnetic dipole field controlled by LRC circuit is designed. The field source can adjust the oscillation frequency and attenuation rate through the resistance in the circuit to obtain the high-energy and penetrating time-domain electromagnetic wave signal. Theoretical analysis and calculation results show that the attenuation of the received waveform is far greater than the attenuation due to the decrease of the resistivity. When the observed distance is large or the resistivity is small, the recorded time-domain waveform is approximately the source The envelope of the signal is relatively simple and easy to measure when traveling at its peak to achieve high-resolution imaging.