Dong Jian, Li Qianqian, Deng Lianwen
School of Information Science and Engineering, Central South University, Changsha 410083, China.
School of Physics and Electronics, Central South University, Changsha 410083, China.
Sensors (Basel). 2017 Feb 10;17(2):349. doi: 10.3390/s17020349.
Ultrawideband (UWB) antennas, as core devices in high-speed wireless communication, are widely applied to mobile handsets, wireless sensor networks, and Internet of Things (IoT). A compact printed monopole antenna for UWB applications with triple band-notched characteristics is proposed in this paper. The antenna has a very compact size of 10 x 16 mm2 and is composed of a square slotted radiation patch and a narrow rectangular ground plane on the back of the substrate. First, by etching a pair of inverted T-shaped slots at the bottom of the radiation patch, one notched band at 5-6 GHz for rejecting the Wireless Local Area Network (WLAN) is generated. Then, by cutting a comb-shaped slot on the top of the radiation patch, a second notched band for rejecting 3.5 GHz Worldwide Interoperability for Microwave Access (WiMAX) is obtained. Further, by cutting a pair of rectangular slots and a C-shaped slot as well as adding a pair of small square parasitic patches at the center of the radiating patch, two separate notched bands for rejecting 5.2 GHz lower WLAN and 5.8 GHz upper WLAN are realized, respectively. Additionally, by integrating the slotted radiation patch with the narrow rectangular ground plane, an enhanced impedance bandwidth can be achieved, especially at the higher band. The antenna consists of linear symmetrical sections only and is easy for fabrication and fine-tuning. The measured results show that the designed antenna provides a wide impedance bandwidth of 150% from 2.12 to 14.80 GHz for VSWR < 2, except for three notched bands of 3.36-4.16, 4.92-5.36, and 5.68-6.0 GHz. Additionally, the antenna exhibits nearly omnidirectional radiation characteristics, low gain at the stopbands, and flat group delay over the whole UWB except at the stopbands. Simulated and experimental results show that the proposed antenna can provide good frequency-domain and time-domain performances at desired UWB frequencies and be an attractive candidate for portable IoT applications.
超宽带（UWB）天线作为高速无线通信中的核心器件，被广泛应用于移动手机、无线传感器网络和物联网（IoT）。本文提出了一种用于UWB应用的具有三频段陷波特性的紧凑型印刷单极天线。该天线尺寸非常紧凑，为10×16 mm²，由一个方形开槽辐射贴片和基板背面的窄矩形接地平面组成。首先，通过在辐射贴片底部蚀刻一对倒T形槽，产生一个5 - 6 GHz的陷波频段，用于抑制无线局域网（WLAN）。然后，通过在辐射贴片顶部切割一个梳形槽，获得第二个用于抑制3.5 GHz全球微波接入互操作性（WiMAX）的陷波频段。进一步地，通过在辐射贴片中心切割一对矩形槽和一个C形槽，并添加一对小方形寄生贴片，分别实现了两个用于抑制5.2 GHz较低频段WLAN和5.8 GHz较高频段WLAN的独立陷波频段。此外，通过将开槽辐射贴片与窄矩形接地平面集成，可以实现增强的阻抗带宽，尤其是在较高频段。该天线仅由线性对称部分组成，易于制造和微调。测量结果表明，除了3.36 - 4.16、4.92 - 5.36和5.68 - 6.0 GHz这三个陷波频段外，所设计的天线在电压驻波比（VSWR）< 2时，提供了从2.12到14.80 GHz的150%的宽阻抗带宽。此外，该天线具有近乎全向的辐射特性，在阻带处增益较低，并且除阻带外，在整个超宽带范围内群延迟平坦。仿真和实验结果表明，所提出的天线在所需的超宽带频率下能够提供良好的频域和时域性能，是便携式物联网应用的一个有吸引力的候选方案。
