Radiation losses of the dominant mode in round dielectric waveguides
Radiation losses of the dominant mode in round dielectric waveguides
复制标题
圆形介质波导中主模的辐射损耗
作者：
D. Marcuse
在一系列早期论文中提出的辐射损耗理论被扩展到圆形介质波导的主模。该理论应用于计算圆形介质波导的突变台阶、渐变锥度和随机壁扰动的辐射损耗。对于圆形电介质波导的主模来说，由突变台阶引起的辐射损耗以及由此产生的锥形损耗远高于电介质平板波导的相应台阶和锥形的辐射损耗。然而，圆形波导的无穷小随机壁扰动引起的损耗几乎等于板条波导理论预测的随机壁损耗。事实上，由于随机壁扰动，圆杆的主模和圆形电 TE 01 模的损耗非常接近相同。该理论仅限于圆形介质棒的圆形对称变形（直径变化）。承载主导导模的圆形介质波导的台阶引起的辐射损耗已通过毫米波频率下的实验得到验证。
The radiation loss theory that has been developed in a series of earlier papers is extended to the dominant mode of the round dielectric waveguide. The theory is applied to the calculation of radiation losses of abrupt steps, gradual tapers, and random wall perturbations of the round dielectric waveguide. The radiation losses caused by an abrupt step, and consequently the losses of tapers, are far higher for the dominant mode of the round dielectric waveguide than they are for corresponding steps and tapers of the dielectric slab waveguide. However, the losses caused by infinitesimal random wall perturbations of the round waveguide are nearly equal to the random wall losses predicted on the basis of the slab waveguide theory. In fact the losses of the dominate mode as well as the circular electric TE 01 mode of the round rod due to random wall perturbations are very nearly the same. The theory is limited to circular symmetric distortions of the round dielectric rod (diameter changes). The radiation losses caused by steps of the round dielectric waveguide that carries the dominate guided mode have been verified by experiments at millimeter wave frequencies.