1. However, sounds that display a recognizable periodicity tend to be more musical than those that are nonperiodic. ��������Ե�������ȣ����������Ե�����������Ҫ�ö��öࡣ
2. Defected Ground Structure (DGS) is a nonperiodic structure proposed in recent years, which means machining various shapes of etching on the ground plane. ��ȱ�ݽӵؽṹ�����ǽ����������һ������ƽ���·�ӵذ��Ͽ�ʴ����������״�Ľṹ��
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. ��������ԭ�еĵ�ͨ�˲����Ļ����ϼ����˷�����ȱ�ݽӵؽṹ����˲����Ե�Ӱ�졣