Radio frequency (RF) is a term that is often used whenever the topic of wireless communication is discussed. It refers to the oscillation of electromagnetic radiation, which is invisible, yet all around us. This radiation carries the signals that are used for radio and TV broadcast, as well as for mobile phones, Internet devices and even most remotely controlled toys.
RF is a rather general term that can apply to a variety of electromagnetic signals. Waves between 3 Hz and 300 GHz are radio frequencies, but different frequency ranges within this spectrum will have different names and LC notch & bandpass filters.
What Are Microwaves and How Are They Used Today?
RF waves from UHF (Ultra High Frequency) to EHF (Extremely High Frequency), a range which includes frequencies between 300 MHz to 300 GHz are referred to as microwaves. In most people’s minds, the term “microwave” is associated with microwave ovens used to cook food. While this is a very common application of this type of RF waves, it’s far from being the only one.
The military has harnessed the power of microwaves to create a non-lethal weapon called the Active Denial System (ADS). It’s a directed-energy weapon that can keep hostile personnel away from a certain area by heating their skin, which causes a high amount of pain and the sensation of burning, yet is unlikely to cause any lasting injury.
Many portable devices that people all over the world use to communicate use microwaves too. This is the case for mobile phones, as well as WiFi routers and adapters that make wireless Internet possible.
In the days before a nationwide network of fiber optic cables existed, telecommunications providers used microwaves to carry long-distance phone calls in some areas, as this was a more reliable and efficient way of connecting people when compared to standard copper telephone cables.
In more remote areas, microwave transmitters and receivers are still used for phone calls and data transmission.
Future Uses of Microwaves
A lot of research is currently being conducted on microwaves, as they have a highly interesting property: the capability of transmitting power over the air, without using any cables. This could prove very useful in a world dominated by electronic devices, as wireless power transmission could be used to charge them without the need to plug them into a power source.
Microwave energy may also be used on a much larger scale one day. Even though the technology is still in its infancy, scientists believe that microwaves can be used to harvest solar power from space and send it to our planet.
Other RF Waves and Their Uses
Waves not part of the microwave spectrum have plenty of uses as well. RF waves are much better suited for the transmission of signals over long distances, as microwaves travel by line of sight and thus require that the transmitter and receiver be within 40 miles of each other.
RF waves are used for AM/FM radio stations, shortwave radio, as well as many kinds of two-way radio communication systems like walkie-talkies and the CB radios often used by truckers.