【摘要】 首次采用了场的最小二乘方 (LSE)和最小均方误差 (LMS)判据寻找平板波导的等效阶跃折射率 (ESI)模型 ,并通过它预测了平板波导的传输特性。计算结果表明 ,原始波导与等效波导场分布在具有最大近似性的基础上 ,ESI模型可以在一定范围内有效的预测平板波导的传输特性。归一化频率与第一个高阶模的截止频率之比在小于 0 7的情况下 ,用上述两种判据找到的ESI模型预测传输常数相对误差小于 0 0 1 % ,预测归一化传输常数的相对误差小于 1 0 %。更多还原

【Abstract】 A method to find Effective Step-Index(ESI) model based on field matching criter ia of least-square-error(LSE) and least-mean-square(LMS) error is put forward, and the propagation quality from ESI coefficients is predicted. When the ESI model a n d the original waveguide have the best approximated field distribution, the prop agation quality of planar waveguide efficiently can be predicted based on ESI mo del in specific range. When the ratio between normalized frequency and cut-off fre quency of the first higher model is lower than 0.7, the relative error of predic t ing propagation constant from the ESI model is less than 0.01%, and the relative error of predictiong normalized propagation constant is less than 10%.更多还原