Modified Array Calibration for Precise Angle-of-Arrival Estimation
Panarat Cherntanomwong, Takada Jun-ichi, Hiroyuki Tsuji, Ryu Miura · Immunotechnology · 2005
In this paper, an evaluation of calibration data for the antenna array based on measurement data is proposed. A simple calibration method to compensate amplitude and phase errors between array elements is presented. A set of measurement data is collected from a single source whose angle of arrival (AOA) is varied in a known direction. To demonstrate the effectiveness of the calibration method, AOA is estimated based on the MUSIC algorithm. However, from the AOA estimation result, it is found that the calibration data are effective only to estimate AOA close to the angle of the signal used to calculate the calibration data. Moreover, we found that the phase differences of calibration data change with AOA while the amplitude differences do not. Therefore, we propose the least square problem to approximate the phase differences as a function of AOA and then modify the calibration data. The result illustrates the improvement of the calibration data when the least square function is applied to the phase differences.