Measurement of antenna factor of log periodic dipole array antenna by near-field reference antenna method

If the antenna factor is defined as the ratio of incident electric field st rength to the output voltage with zero reflection at the load, relative mea surement of the antenna factor can be carried out using a reference antenna with a known antenna factor. In this study, an antenna factor of a log dip ole array antenna was measured in the 600 MHz to 2 GHz frequency region usi ng a dipole antenna as the reference. It was found that the antenna factor depended on the location of the reference antenna. In order to avoid this p roblem, the measurement should be carried out under the condition where the location of the reference antenna is sufficiently far from the log period dipole array antenna, compared with the length of the latter antenna length . However, in this case, errors may be caused by environmental conditions. Therefore, this article proposes a method to estimate a far-field S-paramet er from a near-field S-parameter. (C) 2000 Scripta Technica.