Comparison of different numerical modelling techniques for reverberation chamber: initial 2D study

Traditionally, reverberation chambers have been used for measuring electromagnetic compatibility (EMC) of electrical devices. More recently, they have also been used for measuring small antennas and even MIMO antenna systems. The reverberation chamber is basically a rectangular metal cavity with many resonant modes and with several different types of stirrers used to stir the modes in order for the device under test (DUT) to see a statistically uniform field environment. As we want to make the stirring as effective as possible, it is important to be able to evaluate the effectiveness of the stirring methods in a controlled manner. The paper considers some numerical models that can be used to study the stirring effectiveness of a reverberation chamber. The methods are applied to two-dimensional (2D) cavities, i.e., a chamber with almost zero height in which the only excited polarization is vertical. With this simple case, computation times are acceptable and the mode stirring is easier to understand without the additional complexity of polarization effects. The study is still realistic, because the depth and width of the chamber are made so large that the mode density is the same as in a full-height chamber. We have validated several codes for calculating the field solution inside a 2D cavity and identified the most promising method. The implementation is readily available for 3D.