This paper presents a novel approach to accurately extract the resonant modes of a mode-stirred reverberation chamber (RC) from measured transmission coefficient. This approach neither requires measurements with a fine stirrer rotation step nor assumes the pole continuity over a stirrer rotation. First, the number of modes to be extracted by the matrix pencil method needs to be overestimated in order to obtain most of the true (physical) modes with high accuracy. As this overestimation also implies the extraction of many spurious modes, the second step consists in automatically filtering these spurious modes based on a time-window increasing technique postprocess without a priori information. Performances of the introduced technique are first shown on a didactic example, especially in the presence of noise, and its limitations when increasing the modal overlap are investigated. Results obtained from measurement performed in a chaotic RC are then presented. The introduced approach allows extracting all the true cavity modes from measurement data while keeping the percentage of spurious modes below 3.5%.

中文翻译：

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通过散射参数测量准确表征混响室谐振模式

本文提出了一种新方法，可从测量的传输系数中准确提取模式搅拌混响室 (RC) 的谐振模式。这种方法既不需要用精细的搅拌器旋转步骤进行测量，也不需要在搅拌器旋转时假设磁极连续性。首先，需要高估矩阵铅笔法要提取的模式数量，才能以高精度获得大部分真实（物理）模式。由于这种高估也意味着提取许多杂散模式，第二步包括基于时间窗口增加技术后处理自动过滤这些杂散模式，无需先验信息。引入技术的性能首先在一个教学示例中展示，特别是在存在噪声的情况下，及其在增加模态重叠时的局限性进行了研究。然后显示从混沌 RC 中执行的测量获得的结果。引入的方法允许从测量数据中提取所有真腔模式，同时将杂散模式的百分比保持在 3.5% 以下。