Speaking about single photons, the shorter the wavelength (or the higher the frequency) the more energy the wave carries. But for "real life EM waves", next to the frequency there is also the amplitude, the number of photons making the wave. Given 2 waves of the same frequency, the bigger the amplitude the more energy the wave carries. So we can trade the total energy of the wave. We may lower the frequency but increase the amplitude so the overall energy of the wave will be the same. Are there any limits to this? Could we for example create a microwave but of such high amplitude that it would carry the same energy as a low amplitude X-ray or even gamma-ray wave?