Far field antenna factor estimation method for super broadband antenna using time-frequency analysis

We are developing a far field gain and antenna factor estimation method for broadband antenna standards. We have already proposed a method for estimating the free space antenna factor of broadband antennas using a time-domain analysis and a pulse compression technique. However to estimate the antenna factor and gain, we are using fixed antenna distance. In this paper, we propose a new estimation method for determining the antenna distance at each frequency that to estimate the far field antenna factor. Our proposed method is based on the techniques of a time domain analysis and a time-frequency analysis using a short time Fourier transform. In the case of a super broadband antenna, the difference between far-field antenna factor and the estimated antenna factor using our proposed method is less than 0.1 dB at 10 m antenna distance and less than 0.2 dB at 3m antenna distance in the frequency range from 30 MHz to 250 MHz.