混响室复合搅拌方式的搅拌效率分析

为了评价混响室在不同搅拌方式下的搅拌效率，提高相关测试的精确度，对独立采样数这一重要指标的计算方法做了简单介绍，并在某大型混响室内，对200, 500, 1000 MHz频点下的机械搅拌与频率搅拌方式的搅拌效率进行了试验分析。结果表明:二者的搅拌效率均与工作频率成正比；在机械搅拌方式下，多个搅拌器在不同转速比下能够显著提高搅拌效率；频率搅拌的搅拌带宽选取越大搅拌效率越高；两种搅拌方式提供的独立采样点数均存在一个上限值。通过分析对比，提出了基于机械搅拌与频率搅拌相结合的复合搅拌方式，并对该方式的搅拌效率进行了重点分析，给出了该方式下独立采样点的计算方法，试验结果表明该复合搅拌方式可显著提高测试样本的独立采样数。

Analysis of stirring efficiency in reverberation chamber with combined stirring

In order to evaluate the stirring efficiency in the reverberation chamber under different stirring modes, and improve the accuracy of the measurement, the method for calculating the number of independent samples which is an important indicator is introduced briefly. The frequencies of 200, 500 and 1000 MHz are chosen to evaluate the stirring efficiency of mechanical stirring and frequency stirring. The calculated number of independent samples shows that the stirring efficiency of the two stirring modes is proportional to the operating frequency. In the mechanical stirring mode, the stirring efficiency can be significantly improved when stirrers work at different speed ratios, and the larger stirring bandwidth is chosen, the higher stirring efficiency can be obtained in the frequency stirring mode, but the number of independent samples has an upper limit in the order of hundreds. Thus the combined stirring method based on mechanical stirring and frequency stirring is proposed, and the stirring efficiency is analyzed deeply, also the formula for calculating the independent samples is given. The test results show that the number of independent samples can be drastically increased under the combined stirring mode.