具有双陷波特性的类Sierpinski分形超宽带天线的设计

为避免窄带通信系统对超宽带(ultra-wideband,UWB)系统的干扰冲突,提出一款具有双陷波特性的新型类Sierpinski分形超宽带天线的设计方法.天线采用由2个正六边形与圆形嵌套迭代而成的3阶类Sierpinski分形结构作为辐射贴片,并采用截短矩形两侧去切角且中间去矩形的缺陷地结构作为天线的接地板,实现了良好的超宽带特性.通过在天线辐射贴片上引入对称倒钩形开路枝节以及在微带线贴片上开倒U形槽,实现了3.6～4.3 GHz和7.2～7.8 GHz的双陷波特性.该天线尺寸仅为25 mm×18 mm×1.6 mm.仿真与实测结果表明:天线在3.3～16.4 GHz的频段内,同时可以滤除C波段卫星通信和X波段卫星通信系统的干扰.除2个陷波频段外,该天线具有较好的全向辐射特性和稳定的增益,适用于各种超宽带通信系统中.

Design of a Sierpinski-like fractalultra-wideband antenna with dual band-notched characteristics

In order to avoid interference problems due to narrowband communication systems, we propose a novel Sierpinski-like fractal UWB antenna with double notch characteristics. The antenna adopts a 3rd-order iterative Sierpinski-like fractal structure with two regular hexagons and a circular nest as a radiation patch, in the meantime, a defective grounding plate with truncated rectangular side and middle rectangular structure is also used to achieve good ultra-wideband characteristics. The double band-notched characteristics at 3.6~4.2 GHz and 7.2~7.8 GHz are achieved by two symmetrical barbed-shaped stubs on the fractal patch and a narrow inverted U-shaped slot on the microstrip feedline. The antenna has a compact size of 25 mm×18 mm×1.6 mm. The results of simulation and measured show that the C-band satellite communication and X-band satellite communication can be filtered out at the frequency range of 3.3~16.4 GHz. Except for the two notched bands, the antenna exhibits nearly omnidirectional radiation pattern and a stable gain, which proves that the antenna is a good candidate for various UWB applications.