中文摘要：

为了设计一种高性能的小型微带滤波器，提出了一种新颖的Ф形缺陷地结构（DGS），在此基础上提出了一种加H形开路枝节的Ф形DGS单元模型，以实现低通特性和提高带外抑制度．采用级联结构设计并制作了一单元、二单元和三单元Ф形DGS低通滤波器．3个Ф形DGS低通滤波器结构紧凑，二单元和三单元Ф形DGS低通滤波器具有高选择性、低插入损耗和良好的通带性能，三单元Ф形DGS低通滤波器的带外抑制度非常高，在40dB以上．测试结果与仿真结果一致，证明了该滤波器可满足小型化和高性能的要求．

英文摘要：

In order to design a high performance miniaturized microstrip filter, a new Ф-shape defected ground structure （DGS） is proposed. A Low-pass filter is designed using the Ф-shape DGS with H shape open stubs line. A one single, two-cascaded and three-cascaded Ф-shape DGS low-pass filters is designed, simulated, fabricated and measured repectively. The transmission characteristics of the two-cas- caded Ф-shape DGS low-pass filter shows its advantages of compact size, high selectivity, low insertion loss and excellent pass-band performance. The frequency response of the three-cascaded Ф-shape DGS low-pass filter presents the advantages of compact size; high selectivity; low insertion loss; better pass- band performance and high out-band suppression of more than 40 dB. Measurement shows a good agreement with the simulated results. It also validates the requirements of miniaturization and high performance for filters.