一种新型平面结构的双陷波超宽带天线设计

Design of a Dual Band-notched UWB Antenna with Novel Planar Structure

为了避免现存的一些窄带通信系统对超宽带天线的干扰，提出了一种具有双陷波特性的超宽带天线结构。由于采用了渐变式阶梯阻抗匹配结构作为超宽带基础天线的馈电，使天线具有了宽阻抗匹配能力。通过在基础天线背面附加双偏T寄生单元和在辐射贴片上开窗的联合方法，实现了超宽带天线的双陷波特性。天线电流分布结果可以完全反映出在陷波频率下两种方法的谐振抑制作用，而且实验结果表明该结构的天线对WLAN（5.15~5.825 GHz）和WiMAX（3.4~3.69 GHz）频段的信号起到了有效的抑制作用，同时在工作频段内表现出较好的全向辐射特性。

To avoid interference from existing narrowband communication systems, an ultra wideband （ UWB） antenna with dual band-notched function is proposed. The modified base antenna structure has a wide impedance matching characteristic because of gradual stepped impedance feeder. The proposed anten-na realizes dual band-notched function for UWB antenna by combining two biased T-shaped parasitic ele-ments in the rear side with a window aperture on the radiation patch. The antenna current distributions re-flect resonant suppression of the two methods. Besides, the experimental results demonstrate that the pro-posed antenna prevents signal interference from WLAN （5. 15 ~5. 825 GHz） and WiMAX （3. 4 ~3. 69 GHz） effectively. However it has better omnidirectional radiation patterns in working frequencies.