Reverberation Chamber Enhanced Backscattering: High-Frequency Effects

The need for accurate efficiency measurements at high frequencies of large form-factor devices is ever increasing. In this work, the potential of performing antenna efficiency measurements in an electrically extremely large (up to 250λ) reverberation chamber is investigated and compared to its use at lower frequencies. It is found that there are large deviations in the enhanced backscattering constant at high frequencies. Closer investigation, by introducing a position-dependent enhanced backscattering constant calculation, shows that the deviation mostly occurs at the horn antenna directed at the stirrer. This could be aggravated by the use of a moving wall type of stirrer. The work concludes by demonstrating the potential impact of these deviations on the antenna efficiency. The deviations clearly show the need for more research into these effects.