两种新型双脊波导传输特性的研究

为了寻找最佳传输特性的对称双脊波导结构，提出了三角形和倒梯形两种新型对称双脊波导．应用有限元分析方法计算了这两种新型对称双脊波导TE模式的传输特性，即截止波长和单模带宽．分析传输特性随对称脊波导结构尺寸的变化关系曲线，得到脊间距越小，单模带宽越高，且单模带宽最大达8.0173;倒梯形对称双脊波导的截止波长较同尺寸矩形、三角形和梯形大，最大达9.5．这些结果将为脊波导器件的小型化提供指导．绘出的主模与第一个高次模的场结构图表明，在三角形对称双脊波导的顶点处场强变化最大，能量损失大．

Study of transmission characters of two kinds of new double-ridge waveguide

In order to find a new kind of symmetrical double ridged waveguide which has optimal transmission characters,the paper puts forward two kinds of novel double ridged waveguides which have triangle and anti-trapezoid ridges respectively.The TE mode's cut-off wavelength and single-mode bandwidth of two kinds of novel double ridged waveguides are calculated by the finite element method.It is shown that the ridged waveguide would gain a higher single-mode bandwidth as the distance of ridges is closer by analyzing transmission character changes along with the change curve of the ridged waveguides'dimensions,and that the maximal single-mode bandwidth is 8.0173.The anti-trapezoid ridge waveguide's cut-off wavelength is longer than rectangle,trapezoid and triangle ridged waveguides which have the same dimensions,and the maximal value is 9.5.These results could provide instructions for miniaturization of ridged waveguide apparatuses.Finally plotted field patterns of the dominant mode and the first higher order show that the field intensity change is most enormous at the triangle ridge waveguide's peak,and that the energy loss is greater.