共面波导宽频带微带缝隙天线的设计与分析

Design and analysis of a CPW-fed broadband microstrip slot antenna

为了扩展微带的天线频宽，减小微带天线尺寸，扩大其在小型化宽频带通信系统的应用，提出一种改进的基于共面波导（CPW）的宽频带微带缝隙天线．采用较低介电常数（εr=2．2）和厚度薄（h=0．8mm）的材料作为微带天线基板，使得天线尺寸缩减了30％．利用CST Microwave Studio仿真软件对其进行仿真，得出输入反射系数曲线S11和辐射方向图，其中心工作频率为3．52GHz，获得52％的阻抗带宽（S11〈-10dB），频率范围是3．07—4．11GHz，频带得到展宽．根据对影响天线性能的主要物理参数进行仿真、分析和优化，得到理想天线尺寸．实验结果表明，共面波导宽频带微带缝隙天线比传统微带贴片天线性能有了较大的提高，采用共面波导馈电是可行性和有效性的．

An improved coplanar waveguide （CPW） based broadband microstrip slot antenna was developed that expands antenna bandwidth and reduces size. This should increase the antenna＇s usefulness in small communication systems. A thinner material （ h = 0.8 mm） with a lower dielectric constant （ εr = 2. 2） was used as the substrate, reducing the required size by 30%. Simulation software-CST Microwave Studio-was used to simulate the antenna and from this its reflection coefficient curve S11 and radiation pattern were obtained. The results of the simulation show that the central frequency is 3.52 GHz, the impedance bandwidth is 52% （S11 〈 -10 dB）, and the frequency range is 3.07 - 4.11GHz, showing that bandwidth is significantly broadened. By analysis and optimization of the main parameters influencing the antennas performance in the simulation, the ideal size for the antenna was determined. The result shows that the performance of CPW broadband microstrip slot antennas can be greatly improved compared to traditional microstrip patch antennas, and the feasibility and effectiveness of the CPW feed were also verified.