The Free Space VSWR validation is done according to J.S. Hollis, T.J. Lyon, L. Clayton: “Microwave Antenna Measurement”, Scientific-Atlanta Inc., Atlanta, Georgia, USA, July 1970.
In order to evaluate extraneous energy from several locations in the chamber, scans in transversal and longitudinal directions to the chamber axis are performed at (400 MHz), 800 MHz, 836 MHz, 1 GHz, 1.5 GHz, 1.88 GHz, 2.4 GHz, 6 GHz, 10 GHz, 12 GHz and 18 GHz in a test volume of 0.5 m (or 1 m) diameter in one height (max. 2 m). Each scan is performed in horizontal and vertical polarisation with a different bore sight angle of the antenna to the measurement axis. This angle is changed in 15° steps to cover a range of 180°.
This measurement is only possible with all the test equipment rented from Seibersdorf.