Abstract:

In the field of artillery and automobile engine ignition， microwave ignition devices have emerged as a prominent area of research. Among these， microwave resonator ignition devices are considered fundamental ignition devices. We propose a fast time-domain finite difference method for simulating the resonant cavity， building upon the traditional finite difference time domain （FDTD） method. The new method writes the differential form of Maxwell's curl equation into matrix form containing the information on the resonant cavity structures and the incident wave frequencies. The instantaneous value of the electric field can be quickly calculated by solving for the power of the matrix. Compared with traditional FDTD， the new method has great time advantages in simulating the resonant cavity’s electric field distribution for a long time. The simulation experiments demonstrate that， for the same resonator cavity， when the simulation time exceeds 100 000-time steps， the proposed method achieves a significant improvement in time efficiency， sometimes even several times or up to 100 times faster. Moreover， the simulation results remain consistent with those obtained from the traditional method.

Key words: microwave resonator cavity, microwave ignition, finite difference time domain （FDTD）, fast FDTD, electromagnetic simulation, ignition

摘要：

在火炮点火或汽车发动机点火中，微波点火装置已成为热门研究方向之一，其中微波谐振腔点火装置是最基本的点火装置。基于谐振腔这一简单电子器件结构，在传统时域有限差分法（finite difference time domain,FDTD）基础上提出一种快速时域有限差分法用来对谐振腔进行电磁仿真。新方法将麦克斯韦旋度方程的差分形式写作矩阵形式，将谐振腔的结构、入射波的频率等信息包含在矩阵中。该方法可以通过求解矩阵幂快速求解从而得到目标时间的瞬时电场值，相较传统FDTD，新方法在长时间仿真谐振腔电场分布具有巨大时间优势。仿真实验表明，对于相同的谐振腔，在仿真时间长度大于100 000个时间步长时，该方法的时间效率可提高数倍甚至百倍，仿真结果仍然保持与传统方法的一致性。

关键词: 微波谐振腔, 微波点火装置, 时域有限差分法（FDTD）, 快速FDTD, 电磁仿真, 点火装置