A Compact Dual-Band Octagonal Slotted Printed Monopole Antenna for WLAN/ WiMAX and UWB Applications

AbstractA compact (20 x 20 mm2 size), coplanar waveguide (CPW) fed, octagonal slotted, dual-band antenna is presented in this paper. The proposed antenna has a simple structure consisting of an octagonal slot, L-shape stub, and a two stepped rectangular patch. The introduction of the L-shaped metallic stubs in the ground plane generates a lower resonance frequency at 2.42 GHz. The proposed antenna is fabricated on a low cost FR4 substrate having thickness of 1.6 mm. The measured impedance bandwidth of the proposed antenna is from 2.40 to 2.46 GHz and 3.2 to 6.2 GHz. It is also shown that the proposed antenna has stable radiation patterns of almost dumb-bell shape in the E-plane and omni-directional shape in the H-plane. The effects of various design parameters on the impedance bandwidth are also studied and presented in detail. The proposed antenna can be used for 3.5/5.5 GHz worldwide interoperability for microwave access (WiMAX), 2.4/5.2/5.8 GHz wireless local area network (WLAN) and 3.1-6.0 GHz Direct-Sequence Code Division Multiple Access (DS-CDMA) / Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) ultra wideband (UWB) applications.摘要 本文提出一款尺寸紧凑（20×20 mm²）的共面波导（coplanar waveguide, CPW）馈电八边形缝隙双频天线。所提天线结构简洁，由八边形缝隙、L形金属枝节与两级阶梯状矩形辐射贴片构成。通过在接地平面引入L形金属枝节，可在2.42 GHz处激发低阶谐振频率。该天线印制于厚度1.6 mm的低成本FR4基板上。实测阻抗带宽分别为2.40~2.46 GHz与3.2~6.2 GHz。研究表明，所提天线的E面辐射方向图近似哑铃形，H面辐射方向图为全向型，辐射性能稳定。本文还详细研究并阐述了多种设计参数对阻抗带宽的影响。所提天线可应用于3.5/5.5 GHz全球微波互联接入（WiMAX）、2.4/5.2/5.8 GHz无线局域网（WLAN）以及3.1~6.0 GHz直接序列码分多址（DS-CDMA）/多带正交频分复用（MB-OFDM）超宽带（UWB）应用场景。