At radio frequency waves they are very present in our daily lives in audio broadcasts, television, internet, among others. these waves are electromagnetic (waves that do not need a propagation medium) and have frequencies lower than that of visible light, ranging from 3 KHz to 300 Ghz. Depending on their characteristics, they can be called AM, FM, UHF or VHF.
At AM type waves (modulated amplitude) have variable amplitude (wave height) as they propagate. On the other hand, FM waves (modulated frequency) propagate through space, changing their frequency value. FM broadcasts have superior quality compared to AM wave broadcasts because they have a longer range and eliminate naturally occurring noise. That is why they are most used in broadcast transmissions. The production of AM waves is cheaper and occupies a smaller range of frequency ranges in the sound spectrum.
AM waves - Modulated Amplitude
FM Waves - Modulated Frequency
Other types of radio frequency waves used in our daily lives are UHF and VHF. At
Ultra High Frequency (UHF - Ultra High Frequency) are in the range of 300 MHz to 3 GHz and are widely used in high definition TV broadcasts, bluetooth and wireless. Jat the Very High Frequency (VHF - Very High Frequency) they are in the range of 30 to 300 MHz and are generally used in FM radio and television broadcasts. Currently, mainly due to the lower number of interferences, television broadcasts are migrating from VHF to UHF.In Brazil, the agency that regulates and supervises the use of the radio frequency spectrum is Anatel (Agency National Telecommunications), which provides a document in which there is a distribution of frequency bands in the parents.
The table below was built from data made available by Anatel and shows some frequency values and their uses allowed by the regulatory body.
By Joab Silas
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/fisica/o-que-e-onda-radiofrequencia.htm