基于交指型缺陷接地结构的共面波导

Interdigital Defected Ground Structure Based Coplanar Waveguide

提出了一种在缺陷接地结构(DGS)中用交指电容代替缝隙电容的方法.将交指电容用于DGS共面波导,与缝隙电容DGS相比,交指电容DGS更能使电容的耦合加强,它增加了电容值,使得电路尺寸之间的倍数关系减小,有利于电路的设计和制作,滤波深度和滤波的陡峭程度显著增大,有效改善了DGS共面波导的特性.同时,将该结构用于共面波导贴片天线的设计中,得到了基于交指型DGS的超宽带共面波导天线,与没有DGS的共面波导天线相比,新型天线的带宽增加了600 MHz,其相对带宽由84%提高到103%,达到5个倍频程.

A new method which uses interdigital capacitance instead of slot capacitance in defected ground structure （DGS） was presented. Firstly, interdigital capacitance was used in DGS coplanar waveguide （CPW）. Compared with the slot capacitance DGS, interdigital capacitance DGS enhanced the coupling more. It increased the capacitance value, lessened the multiple relationship between circuit sizes to make the circuit design and production easy. The filtering depth and filtering slope were increased significantly, which improved DGS CPW character effectively. Then the structure was used for the CPW antenna design. The ultra-wide band （UWB）CPW antenna based on the interdigital DGS was obtained. Compared with the CPW antenna without DGS, the bandwidth of new antenna increases 600 MHz, and the relative bandwidth increases from 84% to 103%, reaching 5 octaves.