Quality Factor and Shielding Effectiveness Measurement of an Antenna-Free Enclosure in a Nested Reverberation Chamber

Abstract

For a small-sized shielding enclosure, an infinitesimal monopole antenna is installed inside an enclosure to measure the quality factor and the shielding effectiveness. The characteristic of the monopole antenna, however, affects the measurement of the quality factor and the shielding effectiveness. This article proposes a new measurement method that does not require any antenna installation inside the enclosure. Instead, the proposed method utilizes an aperture on the enclosure surface. A theoretical model is derived for the enclosure response, which represents a response of the enclosure when a pulse signal is incident to the enclosure in the nested reverberation chamber. The response model is used to measure the quality factor and the shielding effectiveness, respectively. The enclosure response affected by an aperture on the enclosure surface is measured, and the measured response is then used to calculate the quality factor by comparing it with the response model. The response model also is used to measure the shielding effectiveness. The enclosure responses are measured with two aperture conditions, respectively, and the shielding effectiveness is calculated using the measured responses. The proposed method is advantageous in that the quality factor and the shielding effectiveness of a small-size enclosure can be accurately measured without being affected by the quality factor of the monopole antenna.