中文摘要：

提出了一种缺陷接地结构（DGS）来实现锐截止低通滤波器，可以获得优异的矩形特性．对DGS进行了精确的FDTD数值分析，研究了其几何尺寸对阻带特性的影响．将FDTD计算结果与有关文献的测量结果进行了比较，一致性很好，从而验证了FDTD程序的有效性和计算的正确性．在微带平面添加短截线，研究了短截线的长度变化对阻带特性的影响．结果表明，改变DGS的几何尺寸可以调节低通滤波器的截止频率，也可以通过调节微带短截线的长度来改变低通滤波器的截止频率，这种关系能为该类锐截止低通滤波器的分析和设计提供指导。

英文摘要：

A sharp-rejection low-pass filter （LPF） with excellent rectangle characteristic is proposed in this paper using a novel DGS. The precise transmission coefficient of the novel DGS is obtained through FDTD analysis. The results of FDTD simulation and measurement in the references verify the validity of the FDTD method. The influences of lattice dimensions on the characteristic of frequency are studied.The influences of straight microstrip line on the characteristic of frequency are also studied in this paper. A method about controlling the cut-off frequency by altering the length of straight microstrip line or the lattice dimensions is presented and discussed. The relationship given in the paper will provide a powerful tool for the analysis and design of LPF using the novel DGS.