in order to obtain maximally flat response passbands, the numerical results show that the proper coupling coefficients should be symmetric and smaller in the middle of the structure.
对于串联结构,影响其特性的主要因素为环与环间的耦合系数.要实现最大平坦的通带特性,通过数值计算得出各个环间耦合系数必须从中间到两侧对称增加的特性。