Answer:
The frequencies are the same.
Step-by-step explanation:
This is similar to the photoelectric effect. The frequency of the electromagnetic wave has to match a threshold frequency before it can set electrons into oscillation in a receiving antenna. After the frequency of the electromagnetic waves have matched and exceeded this threshold frequency, all of it's energy is converted to the kinetic energy of the electrons it sets into oscillation. And since their energies are similar, the frequencies too, subsequently, will be the same.