【作者】 张恒；

【导师】 杨莘元；

【作者基本信息】 哈尔滨工程大学 ， 通信与信息系统， 2005， 硕士

【摘要】 本文研究了用平面近场扫描技术测量超低旁瓣天线时,产生的随机幅相误差和有限扫描面截断误差的补偿方法。 本文首先对天线近场测量技术的背景和现状进行了介绍,给出了近场测量的基础理论和相关知识,然后建立了超低旁瓣天线旁瓣测量总误差与待测天线参数、近场幅相测量总误差的数学模型。并且分析了随机幅相误差产生的测量误差和有限扫描面截断所导致的测量误差,所导致的测量误差对天线远场方向图所引入的误差上界;采用了天线阵模型将随机幅相误差和有限扫描面截断误差对超低旁瓣天线远场方向图旁瓣影响程度的数量级进行了计算机仿真,取得了较佳的效果,从而验证了基于近远场变换理论的误差分析方法具有一定的广泛适用意义。最后,从频域的角度提出了减少随机幅相误差和有限扫描面截断误差的补偿方法,并对修正随机幅相误差的“平均法”和一些补偿方法及有限扫描面截断误差在不增大扫描面的情况下引入加权函数和分数阶傅里叶变换的等方法进行了计算机模拟验证,证明它们是修正近场测量误差的较为有效的方法。更多还原

【Abstract】 The dissertation is aimed at the correction method on ultra-low sidelobe antenna performance aroused by amplitude and phase random error and finite scanning truncation error as the planar near- field scanning technique is used.At first, the background and actuality of antenna near- field scanning measurement is introduced .The basic theory and correlative knowledge of near-field measurement is given. Then the expression of sidelobe measurement errors versus the relative parameters of antenna under test (AUT) and near-field amplitude and phase random errors are presented. And amplitude and phase random error and finite scanning truncation error is . analyzed. The error-upper-bounds expressions of antenna pattern errors resulted from the finite scan truncation errors. Then, the effect of the amplitude and phase random errors and the finite scan truncation errors in the near-field measurement on the sidelobe of ultra-low sidelobe antenna patterns are simulated by computer simulation method. This method makes a good result. It proved that error analysis method based on Near Field-Far Field Transformation is applied at large. Finally, the effective methods for these two error sources to be reduced are put forward in the way of Frequency-domain, then "method of average" which is used to correct amplitude and phase random errors and the method without expanding the scanning plane showing by weighted function and fractional Fourier transform for reducing the finite scan truncation errors are made with computer simulation. It proves that they are the effective methods of correction in the area of near field measurement.更多还原