Reducing the LUF of a reverberation chamber based on the concept of MIMO for electromagnetic emission measurements for radio astronomy applications

Abstract

The International Centre for Radio Astronomy Research (ICRAR), a joint venture between Curtin University and The University of WA, is involved in a number of radio astronomy projects, and one of the tasks is the testing of equipment for Electromagnetic Compatibility (EMC). In order not to interfere with radio astronomy signals, electrical and electronic equipment close to, or at, radio astronomy sites must have a very low electromagnetic emission. Before an electronic device or system can be installed, it must be tested against stringent emission limits, and for that purpose it is crucial that the test facility has a very good sensitivity. To increase the sensitivity of the EMC measurements it is planned to convert an existing shielded room into a reverberation chamber. Reverberation chambers are in principle suitable for very sensitive emission measurements. However, they have limitations in respect to the frequency range; to test at low frequencies the chamber has to be big, so that the chamber can maintain the uniform field strength within the working volume. Instead of rotating a stirrer only, this paper studies the possibility to extend the usability of a reverberation chamber to lower frequencies by introducing the concept of multiple-input and multiple-output (MIMO) communication channels. This research project employs both measurements and computer simulation using a Finite Element Method (ANSOFT HFSS).