Calibration of a numerically modeled reverberation chamber

Calibration of a reverberation chamber is a time consuming process, involving a number of parameters that must be optimized for the chamber to pass the calibration requirements. One of the major factors for calibration at the low frequencies is the tuner efficiency (size and complexity of the tuner). Modeling of the tuner before building it is a cost effective option. Many tuner designs can be modeled for a chamber of given size and requirements and the best tuner design can be chosen from the simulation. Calibration of the simulated data to obtain the desired performance both in terms of uniformity and maximization of the usable volume over a range of frequencies may be useful. Numerical modeling of the electromagnetic fields within an enclosed space such as a reverberation chamber is a particularly difficult problem due to the resonant modes supported within the space, leading to poor convergence of computational electromagnetic methods. In this paper, the ability of MLFMA to model the fields within a reverberation chamber with lossy walls and a tuner is investigated and a calibration of the simulated chamber is performed for a specific tuner design and operating frequency of the chamber. The inefficiency of the tuner to stir the fields at a lower frequency is also shown using the power spectral density plots.