中文摘要：

缺陷地结构（defected ground structure,DGS）是在平面微波传输线接地金属板上通过刻蚀周期或非周期的形状,通过改变电路衬底材料的有效介电常数,实现改变微带传输线的等效电路.传统的DGS微带低通滤波器阻带较窄,且阻带抑制特性较差.针对这一问题,对DGS的电路结构进行深入的研究.采用矩形缺陷地结构（R-DGS）,并引入矩形阶梯阻抗并联短截线（R-SISS）和半圆型阶梯阻抗并联短截线（S-SISS）,设计完成了两款基于SISS结构的DGS微带低通滤波器电路.试验结果表明,新型DGS电路技术可以有效地改善通带内的射频传输特性,拓宽阻带带宽,增加阻带抑制,实验测试取得了较好的结果.

英文摘要：

Defected ground structure （DGS） can change the effective permittivity of substrate materials and the equivalent circuit of the microstrip transmission line by etching the periodic or nonperiodic defected pattern on the ground plane of the microwave circuit. The traditional DGS microstrip low-pass filter has a narrow stopband, and the stopband rejection is poor. to solve this problem, the circuit structure of DGS is studied deeply. Two DGS mierostrip low-pass filter circuits based on SISS structure were designed, by the adoption of rectangular defected ground structure （R-DGS）, and the introduction of the rectangular stepped impedance shunt stubs （R-SISS） and semicircle stepped impedance shunt stub （S-SISS）. The simulation results show that the novel DGS circuit techniques can effectively improve the RF transmission character in passband, broaden stopband bandwidth, increase stopband rejection, which are satisfactory.