An experimental and computational investigation of high-accuracy calibration techniques for gain reference antennas

We present a comparative investigation of the pattern integration technique and the two-antenna technique for calibration of standard gain horns; the investigation involves high-accuracy spherical near-field antenna measurements as well as high-accuracy integral equation / method of moments simulations. The experimental results are thus supported by computational results, and the agreement between these demonstrates the high accuracy of both. For the pattern integration technique the computational and experimental directivities are within 0.01 dB. For the two-antenna technique the proximity effect and the mutual reflections are clearly observed, and it is demonstrated that the use of the phase centers separation in Friis' transmission formula significantly reduces the necessary distance between antennas for a required accuracy.