环形微带天线输入阻抗的一种简易计算方法  

A SIMPLE METHOD FOR COMPUTING THE INPUT IMPEDANCE OF ANNULAR-RING MICROSTRIP ANTENNA

作　　者：黄景熙[1] 范治波[1] 

机构地区：[1]武汉大学空间物理系

出　　处：《武汉大学学报（自然科学版）》1990年第2期45-50,共6页Journal of Wuhan University(Natural Science Edition)

摘　　要：本文利用模匹配技术提出了一种计算环形微带天线输入阻抗的简易而精确的方法。由于微带环的边缘场效应,这种天线可模拟为具有有效内外半径的圆柱空腔.考虑了该腔的内外表面的辐射及介质和欧姆损耗。推导出输入阻抗作为环的尺寸、基片的厚度与相对介电常数、馈电位置及有效馈线宽度的函数。这种简易表达式对于优化各种设计参数是非常有用的。从本文计算结果可以看出:非谐振模对于输入电抗的作用与谐振模相比较不可忽略,这些模的存在增加了电压驻波比带宽。本文所计算的输入阻抗数值与有关文献中的实验测量值很好地一致。A Simple and accurate method for the computation of the input impedance of an annular-ring microstrip antenna is preseuted using a mode matching technique.Due to the fringing field effect for the annular ring,the annular- ring microstrip antenna is modeled as the cylindrical cavity with the effective inner and outer radii.Radiation from the inner and outer surfaces of the cavity is taken into account as well as dielectric and ohmic losses.The simple expression for the input impedance as a function of the ring size, thickness,the relative dielectric constant of the substrate,the feed location and the effective feed width is very useful for optimizing various design parameters.It is found that contribution of the nonresonant modes to input reactance can not be negligible compared with the resonant modes.The pres- ence of these modes increases the voltage standing-wave ratio bandwidth of the antenna.The computed values of the input impedance are compared with the measured values in the literature showing a good agreement.

关 键 词：微带天线 环形 输入阻抗 模匹配 

分 类 号：TN823.15[电子电信—信息与通信工程]