Advances in Radio Science www.adv-radio-sci.net 1684-9965 1684-9973 3 Kleinheubacher Berichte 2004 2005 10.5194/ars-3-99-2005 http://www.adv-radio-sci.net/3/99/2005/ http://www.adv-radio-sci.net/3/99/2005/ars-3-99-2005.html http://www.adv-radio-sci.net/3/99/2005/ars-3-99-2005.pdf 99 103 2005-05-12 Measured Response of Local, Mid-range and Far-range Discontinuities of Large Metal Groundplanes using Time Domain Techniques T. Schrader K. Münter S. Battermann H. Garbe Physikalisch-Technische Bundesanstalt, AG 2.21, Bundesallee 100, 38116 Braunschweig, Germany Institut f&#x00FC;r Grundlagen der Elektrotechnik und Messtechnik, Universit&#x00E4;t Hannover, Appelstraße 9a, 30167 Hannover, Germany This work describes a method to detect and to quantify any local or mid-range discontinuity on extended flat metal planes. Often these planes are used for antenna calibration (open area test site - OATS) or the plane could be the ground of a semi-anechoic chamber used in Electromagnetic Compatibility (EMC) testing. The measurement uncertainty of antenna calibration or EMC testing depends on the groundplane's quality, which can be accessed using this method. </p><p style="line-height: 20px;"> A vector network analyzer with time-domain option is used to determine the complex-valued input scattering parameter <u><i>S</i></u><sub><i>11,F</i></sub> of an aperture antenna in a monostatic setup. <u><i>S</i></u><sub><i>11,F</i></sub> contains the information desired about the discontinuities and is measured in the frequency domain with high dynamic range. But only after a linear filtering utilizing the Chirp-Z-Transform the obtained time-domain signal <u><i>S</i></u><sub><i>11,T</i></sub> evidence of local and mid-range discontinuities.