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一、概述在某些天线中,不但要了解和测试天线的主要参数,如方向性、增益、辐射方向图、极化和匹配等。而且也应该了解天线的相位特性。包括天线的相位方向图和相位中心等。在某些情况下,根据天线的相位特性才能更清楚、透彻地了解整个天线系统的性能。从而提高天线的设计水平。在研究相位扫描系统和分析具有特殊方向图的天线以及确定地面反射的影响时,都需要知道天线在远区场相位方向图。根据天线近场区或者在天线的口径面上的相位和幅度特性,就可以知道天线在远场区的情况,利用这一特性,在大天线测试中,就显得方便、省力和实用了,在聚焦天线的设计中,主馈源的位置也应根据天线的相位中心来确定。否则天线的主要性能将会下降,通过相位测量,还可以确定天线罩,透镜等所引起的失真。
I. Overview In some antennas, not only to understand and test the main antenna parameters, such as directionality, gain, radiation patterns, polarization and matching. But also understand the phase characteristics of the antenna. Including the antenna phase pattern and phase center. In some cases, the performance of the entire antenna system can be more clearly and thoroughly understood based on the phase characteristics of the antenna. Thus improving the design level of the antenna. When studying phase-scanning systems and analyzing antennas with special patterns and determining the effects of surface reflections, you need to know the antenna’s phase pattern in the far field. Based on the phase and amplitude characteristics of the antenna near-field region or the aperture side of the antenna, it is possible to know the situation of the antenna in the far-field region. With this feature, it is convenient, labor-saving and practical for large antenna test. In the design of the focusing antenna, the position of the main feed should also be determined according to the phase center of the antenna. Otherwise, the main performance of the antenna will be reduced. By phase measurement, the distortion caused by radomes and lenses can also be determined.