目前国际上提出了采用短脉冲射频(RF)信号实现相对论磁控管的模式切换，数值模拟经证实了可以采用几十kW到几百kW的RF信号实现相对论磁控管采用轴向提取功率的相邻模式以及同一模式的不同纵向模式之间的切换，这里假设所需的RF信号的能量已经馈入到相对论磁控管腔体内。提出了实验系统中采用扇形波导和探针天线来馈入前级微波源来提供模式切换所需的RF信号的能量的方法。该方法分为两个步骤，首先采用扇形波导来将前级微波源提供的能量馈入到相对论磁控管的阳极体中；然后利用探针天线将馈入的RF信号辐射至相对论磁控管腔体内，提供模式切换所需的能量。数值模拟证实了该方法在实际应用中具有可行性以及实用性。

The relativistic magnetron is a crossed-field device and plays an important role in the high power microwave technology and radar system. Recently, researchers realized mode switching in relativistic magnetron between neighbour modes as well as different longitudinal operation modes in the same modes with several hundred kilowatts RF input signal. Unfortunately, the RF input power is assumed to already power into the relativistic magnetron cavity, though in reality not considering such work. A novel RF input technology is proposed in this article, using a rod antenna to couple the input RF signal from the input sector waveguide into the relativistic magnetron cavity. In the PIC simulation with UNIPIC code, by adjusting the antenna position and the antenna configuration, the coupling efficiency between the antenna and input sector waveguide can be optimized. This new method can be used in power and energy input for mode switching, and the simulation results can be used as references for RF signal input in future experiment.