TEM horn antennas are used in ultra-wide-band high-power applications. High reflected peak powers can threat and damage the pulse generators. In this work, the peak power of the reflected pulse is reduced by loading series LC circuits at the endings of a linearly-tapered TEM horn antenna. Blend edges at the endings are also applied. The influences of the blend edges and LC components on the reflected pulse and radiation performances are simulated using CST MS Studio. The dispersive propagation of the wave caused by the loaded LC components is considered as the mechanism of the reduction of the peak power of the reflected pulse, which is effectively reduced by 45%. Meanwhile the peak-to-peak voltage monitored at a point in far-field on the bore-sight direction remains well and a small enhancement of the low-frequency directivity is observed.