基于分形特征的DGS微带线传输特性分析

缺陷地结构(defected ground structure,DGS)微带线的电磁散射特性取决于缺陷图形的几何特征和导波媒质等因素,因此缺陷图形设计是DGS微波电路设计的关键因素之一.提出一种新颖的DGS微带线.通过有限元法对不同Hilbert曲线宽度和长度的DGS结构微带线进行计算,计算结果表明,该结构在0～9 GHz频段内表现出2.43 GHz和7.11 GHz这2个谐振频率,对应频率的通带反射损耗低于-15 dB,并且阻带特性在谐振频率处比传统DGS微带线有更高的Q值.当Hilbert曲线宽度固定为0.2 mm时,其谐振频率和对应频点的Q值均与曲线长度成反比,最大达123.75;当Hilbert曲线长度固定为1.0 mm时,其谐振频率与曲线宽度成正比,而对应频点的Q值与曲线长度成反比,最大达146.

Transmission property analysis for defected ground structure microstrip line based on fractal characteristic

Since the electromagnetic characteristic of defected ground structure (DGS) on microtrip line depends on the geometric feature and guided wave medium of defected image, the defected image design is one of the key factor for DGS microwave circuit design. Hence, a novel DGS on the microstrip line was presented. The different width and length of Hilbert curve geometries were investigated by finite element method (FEM). The computation results show that the DGS rejects the signal at two frequencies 2.43 GHz and 7.11 GHz from 0~9 GHz with more than -15 dB suppression. Q factors of the Hilbert curve DGS is bigger than that of conventional DGS. When the dimension of Hilbert curve slot width is 0.2 mm, the resonance frequency and the calculated Q factors decreases to 123.75 as the slot length grows. When the dimension of the Hilbert curve slot length is 1.0 mm and the slot width increases, the resonance frequency increases, and its Q factor decreases to 146.