The objective is to make it possible for the maximum number of users to co-exist within the
existing radio spectrum, without interfering with each other.
Radio spectrum is like land . . . no more of it is being manufactured.
The energy of EM radiation depends on its frequency, and the lowest frequency corresponds to the lowest energy. Radio waves are at the low end of the energy and frequency spectrum.
The radio frequency portion of the electromagnetic spectrum uses radio telescopes.
Extremely low frequency (ELF) radio waves. They can have wavelengths of over 60,000 miles (100,000 km) and frequencies from 3 to 300 Hz.
The radio frequency portion of the electromagnetic spectrum uses radio telescopes.
The part that we call "Extremely Low Frequency Radio Waves".
Radio waves are the lowest frequency (and therefore longest wavelength) waves in the electromagnetic spectrum.
That would be sound waves, or the audio spectrum.
Radio waves are electromagnetic waves occurring on the radio frequency portion of the electromagnetic spectrum.
The lowest frequency is effectively zero and this would be in the extremely low frequency (ELF) band in the sub-radio range of the electromagnetic spectrum.
As you move from gamma rays to radio waves on the electromagnetic spectrum, the wavelength gets longer and the frequency decreases. Gamma rays have the shortest wavelength and highest frequency, while radio waves have the longest wavelength and lowest frequency.
Radio waves have the lowest frequency in all of the electromagnetic spectrum. The next higher frequency energy is microwave, visible light including ultraviolet, infrared, X-ray, then gamma ray
RF (Radio Frequency Coil) is a coil, which is designed to resonate at a frequency some where in the radio spectrum frequency. See L C Circuit Link Below.