Far field antenna factor measurement for log-periodic dipole array antenna using the amplitude center distance

We are developing a far field gain and an antenna factor estimation method for EMI broadband antennas using the amplitude center distance and time frequency analysis technique. Our method is using an amplitude center modified Friis transmission formula. In this paper, we show the measurement results of far field antenna factor of log-periodic dipole array antenna on an open area test site. In the case of using the new transmission formula, difference between estimated antenna factor using S₂₁ of 3 m and S₂₁ of 4 m, and estimated antenna factor using S₂₁ of 4 m and S₂₁ of 10 m is less than 0.5 dB in the frequency range from 300 MHz to 2400 MHz.