I'm confused about how these two different formulas for calculating signal
energy. I could really use your help.
1. Using Planck's constant, the energy of an electromagnetic plane wave is
Energy = (6.625*10^(-34)) * (frequency of the signal)
So, as the frequency is increased, the energy increases as well. Ionizing
radiation would fall into the
high energy realm of physics. Now, my confusion starts.
Does this only hold when looking at the signal as light -> photons?
Why doesn't signal amplitude play into this equation?
2. On the other hand, if I have a rectangular pulse, f(t), representing a high
bit being transmitted through a communication channel, of amplitude A with
period T (or frequency F), the signal energy is given by:
Energy = Integral from 0 to T of f(t)^2 = (A^2)*T = (A^2)/F since T = 1/F
So, in this case, as the frequency increases, the energy decreases. This makes
sense to me. Cell phones with high frequency transceivers use
less energy than their old lower frequency analog counterparts - yielding
longer battery life but can't trasmit a signal as far.
Do you see my contradiction. I'm confused here, please help. Thanks.