Fast and accurate prediction of reverberation chambers´ resonant frequencies using time-domain integral equation and matrix pencil method

Unstirred frequencies of a reverberation chamber (RC) are attributed to its discrete mode distribution. Transient analysis is usually preferred in predicting an RC´s mode distribution. For its geometrical flexibility, the time-domain integral equation (TDIE) is suitable for transient analysis of RCs containing stirrers of arbitrary shape. Due to the resonant nature of an RC, a large number of marching steps are usually required for the accurate prediction of resonant frequencies. This paper adopts the TDIE to efficiently obtain the early time response of an RC, and utilizes the matrix pencil method to accurately calculate its resonant frequencies. The proposed method can accurately predict an RC´s resonant frequencies using the early time information, and it shortens the time-consuming TDIE simulations.