不同参数对同轴布喇格结构频率响应的影响

Influence of different parameters on frequency response of the coaxial Bragg structure

基于多模耦合理论,对影响低频(15 GHz)单模和高频(0.35 THz)耦合模式同轴布喇格结构频率响应特性的参数进行了比较研究.结果表明,初始相位、波纹周期、加窗技术、开槽深度、开槽形状、波纹壁的加坡度方式和坡度角以及结构长度等参数,对同轴布喇格结构频率响应特性都有影响.一般设置内外导体波纹相位差为180°,且内外导体波纹周期相同;加窗技术可很好地抑制残留边带;改变开槽深度、开槽形状、加坡度方式以及结构长度可以改变同轴布喇格结构的频带宽度和反射率,尤其对于高频耦合模式,其工作模式和竞争模式受参数影响的变化规律不同,根据这些特点可以按照实际需要选择合适的参数,提高模式的选择性,改善同轴布喇格结构的性能.

Based on the coupling theory, numerical simulations are carried out for the influence of different parameters on frequency response of a coaxial Bragg structure with low frequency （15 GHz）single-mode and high frequency （0.35 THz）coupling modes. Results show that the initial phase, the ripple period, windowing-function technique, the sinusoidal ripple amplitude, the ripple shape, the mode of gradient and the gradient, and the length of a coaxial Bragg structure all evidently influence the frequency response of a coaxial Bragg structure.The inner and outer conductors of corrugated coaxial Bragg structure phase difference is set to 180° ,the ripple period is the same,the window technique can well inhibit the residual side-lobes, and when we change the sinusoidal ripple amplitude, the ripple shape, the mode of gradient and the length of the structure can change the bandwidth and reflectivity of coaxial Bragg structure, especially for the high frequency coupling modes, the influence of different parameters on the working mode and competition mode is different.Therefore, different parameters can be properly chosen to improve the mode selectivity of coaxial Bragg structures and to improve the performance of coaxial Bragg structure.