Hello Group. We are trying to establish correlation between our site and a site in Europe. One of the issues is antenna calibration.
Due to ambients, we do our tests at 3 meters. Because we measure at 3 meters, we also did the NSA profile at 3 meters and had our antennas calibrated at a 3 meter distance. Striving to have the most accurate measurements, both NSA and actual product test data, we also had the antennas calibrated in both the horizontal and vertical polarization at an outside test lab. According to C63.5, broadband antennas as typically used in measurements between 30 MHz and 1 GHz, will have only a small variation in antenna factors between the vertical and horizontal polarizations. Therefore, the usual antenna factors provided are for the horizontal polarization only. We are using a biconical antenna for low band and log periodic for high band. For the bicon, imagine my surprise when I found the difference in antenna calibration factors between horizontal and vertical polarization to be as much as 5 dB. If I used the horizontal factors only for vertical measurements, I could be noncompliant with the NSA +/- 4dB window due to this disparity alone. Has anyone had a similar experience? What should be typical differences in antenna factors between horizontal and vertical polarizations? Regards, Don Umbdenstock umbdenst...@sensormatic.com
