If I hook up a HF ultra-wideband (UWB) amplifier with a transmitting UWB antenna (out) and a receiving UWB antenna (in) and have the antennas very close (few inches) to each other inside a metal box (~40cm) so as to produce a feedback loop, then due to the noise and harmonics of the over-driven amplifier clipped-waveform, it would then add more frequencies with each loop, resulting in an exponential growth in the amount of frequencies (to the limit of the amplifier and antennas), is that correct?