Articles | Volume 5
Adv. Radio Sci., 5, 427–434, 2007
https://doi.org/10.5194/ars-5-427-2007
Adv. Radio Sci., 5, 427–434, 2007
https://doi.org/10.5194/ars-5-427-2007

  13 Jun 2007

13 Jun 2007

Contactless electromagnetic measuring system using conventional calibration algorithms to determine scattering parameters

T. Zelder, H. Rabe, and H. Eul T. Zelder et al.
  • Institut für Hochfrequenztechnik und Funksysteme, Universität Hannover, Appelstraße 9A, 30167 Hannover, Germany

Abstract. In this paper, a contactless measuring system for the determination of the S-parameters of planar circuits is presented. With a contactless measuring system it is possible to characterise a device-under-test (DUT) embedded in a planar circuit environment without cutting the planar transmission lines connecting the DUT. The technique utilizes four identical capacitive probes in conjunction with a vector network analyser (VNA). For the usage of electromagnetic probes compared to other coupling techniques like the electro-optic probing, there is no need for expensive and complex equipment in addition to the typical equipment of a common microwave laboratory. The S-parameters are determined accurately using conventional calibration methods. A simple analytical model for the representation of the basic characteristics is developed. Furthermore, the influences on the S-parameters as a result of a variation in the coupling are presented. With the knowledge of the system characteristics, an accurate contactless measurement system is set up. The comparison between conventional and contactless measurements in a frequency range of 1–20 GHz shows a very good agreement with a phase error smaller than 1°.