电波混响室最低可用频率估算方法研究

Estimation Method Study of the Lowest Usable Frequency of the Reverberation Chamber

为了满足混响室场均匀性要求,每个混响室都有一个最低可用频率.混响室最低可用频率一般与混响室的大小以及搅拌器的搅拌效率有关,混响室体积越大,最低可用频率越小.对最低可用频率的估算,目前相关标准介绍了2种方法：一种方法是在最低可用频率处,保证混响室内至少有60个模,另一种方法规定混响室最低可用频率是最低谐振模频率的3~4倍.若混响室尺寸一定,2种方法估算的结果可能不同.针对一个已知尺寸的混响室进行了仿真研究,结果表明,对于所选混响室,2种估算方法所得结果基本一致,且估算结果对应的场均匀性满足标准对容许偏差的要求.

In order to satisfy the need of field uniformity,every reverberation chamber has a lowest usable frequency.The lowest usable frequency is often relevant to the size of the reverberation chamber and stirring efficiency of the stirrers.The more the size of the reverberation chamber is,the lower the lowest usable frequency is.The estimation of the lowest usable frequency plays an important role in the devising and making reverberation chamber and finding the size of a reverberation chamber in advance.In relevant standards,there are two methods used to estimate the lowest usable frequency at present.One method is that there are 60 modes at least in the reverberation chamber at the lowest usable frequency.The other method is that the lowest usable frequency is 3to 4times than the lowest resonance frequency.Which method is more reasonable？To size-different reverberation chamber,the answer may be different.But if the size of the reverberation chamber is confirmed,the estimating results of the two methods may be different.Here we can choose the more effective estimating method.This paper does a deeper simulation study to a size-known reverberation chamber.The study indicates the result by the two estimating methods is uniform.