Thermal Noise Measurements in a Reverberation Chamber

The letter describes the properties of thermal noise measured in an electromagnetic reverberation chamber. The consequences for the detection of weak signals in the presence of the noise are outlined.

Thermal Noise Measurements in a Reverberation Chamber

The letter describes the properties of thermal noise measured in an electromagnetic reverberation chamber. The consequences for the detection of weak signals in the presence of the noise are outlined.

Quantification of the Absorption and Scattering Effects of Diffusers in a Room with Absorbent Ceiling

In ordinary public rooms, such as classrooms and offices, an absorbent ceiling is the typical first acoustic action. This treatment provides a good acoustic baseline. However, an improvement of specific room acoustic parameters, operating for specific frequencies, can be needed. It has been seen that diffusing elements can be effective additional treatment. In order to choose the right design, placement, and quantity of diffusers, a model to estimate the effect on the acoustics is necessary. This study evaluated whether an SEA model could be used for that purpose, particularly for the cases where diffusers are used in combination with an absorbent ceiling. It was investigated whether the model could handle different quantities of diffusing elements, varied diffusion characteristics, and varied installation patterns. It was found that the model was sensitive to these changes, given that the output from the model in terms of acoustic properties will be reflected by the change of diffuser configuration design. It was also seen that the absorption and scattering of the diffusers could be quantified in a laboratory environment: a reverberation chamber. Through the SEA model, these quantities could be transformed to a full-scale room for estimation of the room acoustic parameters.

Optimization of the Measurement Technique for Emissions in Reverberation Chamber Using the Equivalence Principle

This paper presents an optimization of a method to reconstruct the radiated emissions of an equipment under test by the measurement of the electric field samples collected on the walls of a reverberation chamber. This means that only the orthogonal component of the electric field is necessary to obtain the radiative behavior of the device in free space conditions. The use of the equivalence principle allows one to reduce the number of equivalent sources used to reconstruct the radiation of the device. In fact, in the previous version of the method, the sources are placed into the entirety of working volume of the reverberation chamber. In the current version of the method, only the surface surrounding the equipment under test is discretized. The analytical implementation of the method is proposed for a particular stirring action: the multiple monopole source stirring technique. This technique is based on an array of monopoles placed onto the walls of the cavity, and therefore no further hardware is needed for the reconstruction of the radiated emissions. The method is experimentally validated in a real scenario.