应用传输矩阵法研究了以三层单负材料组成周期单元的异质结构光子晶体(ABA)M (CDC)N(ABA)M(CDC)N的光子禁带，相比于由两层单负材料构成的光子晶体(AB)M，具有更狭窄 的通带，对结构周期数和入射角同样是不敏感。研究还发现，平均介电常数和平均磁导率均为零的 该异质结构，其能带宽度随晶格常数的增大而逐渐变窄，这一特性可以用来设计单通道滤波器件， 同时由于电磁波有效波矢量为零，利用这一特点可以设计零有效相位延迟滤波器。

The one-dimensional photonic band-gap (PBG) of heterostructures consisting of three single-negative materials is studied with transfer matrix method，which ，compared with the Bragg gaps，has a narrower bandpass and，is insensitive to the incident angles and period. We also found that the band width of multiple heterostructures of zero average permittivity and permeability gradually becomes narrowed with the increase of the lattice constant，which can be used to design omni-directional single-channel filters and to omnidirectional zreo-phase-shift filters as its effective wave vector is zero.