The Correction of Antenna Factor

The theoretical NSA values given by the standards are grounded on the assumption that transmit and receive antennas are infinitesimal dipole antennas which is inappropriate to measurements. That is. the assumption neglects: (1) antenna mutual coupling, (2) antenna factor variations versus height, and (3) differences between the H-plane directivities for the measurement antennas and an infinitesimal dipole. Therefore, correction of antenna factor is considered requisite for every NSA measurement, especially when tuned dipoles are employed. In this paper, correction factors are calculated with the method of moments at 3m and Win above a finite metal plane, and the results are compared with that given by ANSI C63.4 and CISPR. To solve the problem of values traceability regarding test site, we give the method below which can take the influence of actual test site into account.