RF communication utilizes radio waves rather than wires to exchange signals, and this is where the term "wireless communication," comes from. RF modules generally use frequencies to distinguish the different radio signals, therefore, in order for the RF modules to communicate, they have to be operating on the same exact frequency. That said, you should know that radio frequency is normally measured in units known as hertz (abbreviated as Hz), which represent number of cycles/second when the radio wave(s) is transmitted. 1 hertz (Hz) equals 1 cycle/second, and 1 megahertz (abbreviated as, MHz) equals 1 million cycles/second.
A radio frequency (RF) signal basically refers to the wireless electromagnetic signal that's utilized as a form of communication, when talking about wireless electronics. As mentioned earlier, radio waves are a type of electromagnetic radiation which have identified radio frequencies which usually range from about 3Hz to 300 GHz. Not every radio wave is the same; they can be small or big, or they can be far apart or close together. On the radio stations we normally listen to, every station uses waves which are on a slightly different frequency from the other stations. Whenever you happen to switch from one radio station to another, your radio picks up and then plays waves of that particular frequency.
Frequency normally refers to the oscillation rate of the radio waves. It can also refer to how close together or far apart the waves are. When the radio waves are too far apart, that is known as low frequency, and when the radio waves are close together, that is known as high frequency. That said, you should know that radio frequency propagation happens at speed of light, and doesn't need any medium (such as air) in order for it to travel. Radio frequency waves occur naturally from lightning, the sun flares, and even from stars which radiate radio frequency waves as the get older. However, people usually communicate with man made radio waves which oscillate at various select frequencies.
The man made radio frequency waves are produced by oscillating current for a certain number of times, and radiating it off the conductor (which is referred to as the antenna), into an empty space (this is the space that's occupied by air and not the outer space), as electromagnetic radio waves. The RF signals are received and sent using conductors via the phenomenon that's called the skin effect, where radio frequency current latches itself and then flows through the conductors' surface; this effect is actually the basis and the core of radio technology.
The best thing about RF communication, is that it's omnipresent (that is to mean it's all around us). It plays a crucial role in many of the communications systems which we depend on a daily basis, such as fire and police radio systems, TV and radio broadcasts, and satellite communications. Cordless phones, cellphones, Wireless internet (Wi Fi), and Bluetooth also operate in the radio frequency spectrum. In addition to that, there are other appliances outside of the communications field that use RF. They include; microwave ovens, garage door openers, among others. Some wireless devices such as TV remote controls, cordless computer mice, computer keyboards, and even two way radios also operate using RF frequency.
Two way radios are based on the RF frequency and they perform group communication using minimum radio frequency channel resources. This is to mean that if all the users are in the same location or area (most of the time), you will only need a single channel resource in order to talk to them. By using RF, 2 way radios have the capability of facilitating âone to manyâ group communication (which is also known as a group call), very efficiently. By efficient, I mean that 1 user can communicate/talk to 1, 5, 10, 100 or even 1000's of users at a go. The 2 way radio user doesnât need to keep on repeating the same message if he/she needs to convey to many users.