Measurements of complex antenna factor by the near-field 3-antenna method

The near-field 3-antenna method for measuring the complex antenna factor (CAF) is proposed in order to reduce the effect of the measurement site and background noise. The transmission coefficients in the far-field region are calculated from those measured in the near-field and theoretically obtained near-field correction factors (NCF). The CAF of monopole antennas are measured using the proposed method in a frequency range up to 6 GHz. From the measurement results, the dependency of CAF values on the antenna distance is small. These results indicate that our theory including the NCF is applicable for the measurements of the CAF of simple-structure antennas.