Some remarks on antenna response in a reverberation chamber

The simple formula, (Pr)=(E02 /(eta))((lambda)^2/8(pi)), for the received power of an antenna with a matched load in an over-moded cavity actually holds for an antenna of any shape and size. This can be seen from the close connection between the correlation tensor of the cavity field at two different points and the imaginary part of the free-space dyadic Greenʹs function