Abstract—Antenna miniaturization plays an important role in modern wireless communication and has got some serious limitations. Gain and bandwidth degradations are two vital limitations in miniaturized antennas. Another problem faced by small antennas is efficiency degradation. This paper presents a compact dual-band serpentine-shaped antenna with folded stub lines having a total volume of 10 × 13 × 1.524 mm³ and mounted on the partial ground plane with the dimensions of 10 × 6.5 × 0.035 mm³. A size reduction of 82% (including ground plane) is achieved compared to the conventional square patch antenna working at 6.8 GHz. The proposed antenna is linearly polarized. The antenna is fed with a 50-ohm microstrip line. The radiating element of the proposed antenna is connected to quarter-wavelength folded stub lines. The measured by –10 dB level impedance bandwidths of the proposed antenna are 660.6 MHz (6.6–7.26 GHz) and 1.52 GHz (8.84–10.36 GHz) which covers C- band (4–8 GHz) and X-band (8 ~ 12 GHz) applications. Measured gains of 3.2, 5.41 and 5.56 dBi along with the measured efficiencies of 82.1, 86.3, and 88.1% are obtained at 6.8, 9.51, and 9.89 GHz respectively. The radiation patterns of the proposed antenna are found to be unidirectional in all the planes at 6.8 GHz, uni-directional in E-plane and omni-directional in H-plane at 9.51 GHz and uni-directional in all the planes at 9.89 GHz. All the measured and simulated results are in good agreement.

摘要—天线的小型化在现代无线通信中起着重要的作用，并存在一些严重的局限性。增益和带宽下降是微型天线的两个重要限制。小天线面临的另一个问题是效率下降。本文提出了一种紧凑的双频带蛇形天线，其折叠的短截线总体积为10×13×1.524 mm ^3，并安装在尺寸为10×6.5×0.035 mm ³的局部接地平面上。与工作在6.8 GHz的常规方形贴片天线相比，尺寸减小了82％（包括接地平面）。提出的天线是线性极化的。天线装有一条50欧姆的微带线。所提出的天线的辐射元件连接到四分之一波长的折叠短线。拟议天线的以–10 dB的水平阻抗带宽测得的带宽为660.6 MHz（6.6–7.26 GHz）和1.52 GHz（8.84–10.36 GHz），覆盖C频段（4–8 GHz）和X频段（8〜12） GHz）应用。在6.8、9.51和9.89 GHz时分别获得3.2、5.41和5.56 dBi的测量增益以及82.1、86.3和88.1％的测量效率。发现拟议天线的辐射方向图在所有平面均为6.8 GHz时是单向的，在E平面为单向，而在H平面为9时是全向。51 GHz，并且在所有平面中都是单向的，频率为9.89 GHz。所有的测量和模拟结果都吻合良好。