1. However, sounds that display a recognizable periodicity tend to be more musical than those that are nonperiodic. 与非周期性的声音相比，具有周期性的声音听起来要悦耳得多。
2. Defected Ground Structure (DGS) is a nonperiodic structure proposed in recent years, which means machining various shapes of etching on the ground plane. 即缺陷接地结构，它是近年来提出的一种在微波平面电路接地版上刻蚀出非周期形状的结构。
3. Furthermore, the effect of Combinatorial Nonperiodic Defected Ground Structure (CNPDGS)on the characteristic of the low-pass filter formed by the CNPDGS structure is studied. 分析了在原有的低通滤波器的基础上加入了非周期缺陷接地结构后对滤波特性的影响。
