Proximity and orientation influence on Q-factor with respect to large-form-factor loads in a reverberation chamber

In this paper, it is shown that the presence of large-form-factor loads in close proximity to an antenna under test can affect the measured Q-factor (if measured improperly) in a reverberation chamber (RC), possibly influencing the results of further calculations such as antenna efficiency. It is shown that the slope of the power-delay profile of a measurement in a reverberation chamber is unaffected by the antenna´s proximity to large-form-factor loads. Furthermore, when a RC is loaded, the loading can bias the frequency-domain data calculation of Q in a way that gives a different Q when calculated from time-domain data. In a sense, the loading acts as an additional effective antenna load, and as such the time-domain approach for determining Q should always be used in loading situations.