Speaking of meanings of words, there is a distinction between generation and emission of signals. Organic substances might be able to emit RF signals without generating them. How can this be? By the heterodyning principle. If two signals of nearly equal frequencies are mixed in a so-called nonlinear medium, that medium may emit signals at frequencies equal to the sum and difference of the original two frequencies. The latter might be much lower than the two nearly equal frequencies that generated it by their mixing in the nonlinear medium.
Matthew
