波纹圆形槽波导的色散特性

The Dispersion Behavior of Corrugated Circular Groove Waveguides

依据弗洛奎定理,在考虑空间谐波影响的情况下,利用边界场的连续性条件,导出了波纹圆形槽波导的色散方程。在此基础上进一步通过数值计算,分析了波导的几何结构参数对其传输主模HE11的低频截止点、高频截止点和快慢波分界点的影响,从而得到了波导的色散特性。数值分析结果表明,改变波导波纹凹槽的外、内径之比(b/a),可影响传播模式的频宽;调整纵向开槽的宽度(c/a)则可有效抑制高阶模的产生,这有助于扩展单模传输的频带宽度。文章最后利用波导谐振腔法测量了波导波长,实验值与理论值符合良好。

In this paper, by means of the field continuity at the interface of two neighboring regions, the dispersion equation of corrugated circular groove waveguide （CCGW） is derived based on Floquet＇s theorem. To the dominant mode, the low-frequency cutoff, the high-frequency cutoff and the critical condition between fast-wave and slow-wave, which are influenced by waveguide configuration parameters, are analyzed. The numerical results show that the passband of the guide is influenced by the ratio b/a, and the high-order modes can be restrained by means of choosing an appropriate groove width. Finally, using a resonance technique, the guide wavelength of CCGW is measured, which shows the theoretical results of the guide wavelength are in good agreement with the measured results.