使用多天線法量測天線增益及相位中心

Abstract

摘要 本論文敘述使用三天線法及多天線法,分別量測天線增益與相位中心,並利用於不同天線距離所量測到的S參數,計算發射與接收天線間的路徑長度。藉由三天線法與反射式RCS量測,可證明天線相位中心位置為頻率函數,並可利用不同距離所量測到之S21參數,求出發射天線與接收天線間的距離,以提高三天線法量測天線增益的準確度。本論文進而建立多天線法,可同時獲得多個測試天線之增益及相位中心,並由量測數據討論增益之精準度。

Abstract In this thesis, the antenna gain and phase center are calculated from a set of S21 measurements at two different distances using the three-antenna method and the multi-antenna method. By using the three-antenna method and the S21 measurement in a reflection-type RCS arrangement, the phase center of antenna is measured and verified as a frequency dependent value. In addition, the path lengths between the transmitting and receiving antennas can be calculated from a set of S21 measurements, the measured antenna gain using three-antenna method given in Chapter 4 is shown to be accurate and distance independent. The approach of multi-antenna method is then presented in Chapter 5 with experimental results to measure the antenna gain and phase center of the test antennas in a cost-effective manner.