Radio frequency is simply the fluctuation speed of an electrical or non-electric current or of a non-magnetic, electromagnetic or electrical field or fluid in the frequency region from around 200 kHz to about 30 GHz. It is usually measured in decibels (dibe) but lower frequencies tend to be less susceptible to external influences such as noise. Some typical electrical devices use radio frequency signals for their power supply, communication and heating purposes. A typical telephone handset may employ radio frequency to send and receive calls. In some cases, radio frequency is used to control machines such as printers, television sets and car radio tuners. And, of course, many individuals enjoy the advantages of radio frequency powered hobbies such as radio controlled cars, helicopters, sailboats, motorcycles and radios.
With the development of new technology, radio frequency finds its way into other areas as well, most notably in communications. The most widespread applications in which radio frequency finds its way are from microwave and satellite radio transmission. From here it is used to communicate with people all over the world, by both using headphones or ear buds, and by plugging a portable device such as a radio to the receiving antenna. The microwaves penetrate through many objects and bounce off various components of a communication network, resulting in many different channels and frequency combinations. Most microwaves traveling through objects have the same bandwidth as one channel on a satellite dish so a station can transmit signals to any point on earth with an equal advantage over other stations transmitting on the same frequency.
Satellite radio frequencies, on the other hand, operate at much higher speeds, since they are generally unidirectional. The waves are produced in a fixed orbit above the Earth and thus cannot be affected by atmospheric conditions. They also operate in a wider frequency region, covering a greater distance than those afforded by microwaves. As a result, there are far more satellites in operation around the globe than there are radio frequencies in operation within any given geographic area.
Radio frequency currents are also being used for applications outside the communications industry. Some of these are incredibly small, such as the electrical impulses needed for robotic androids. Others are much larger and cover a wide range of issues. The energy currents involved have the potential for harm when their size is combined with the extremely high speeds with which they move, so careful consideration is required when working with them. For this reason, the majority of radio frequencies that humans will be exposed to in the coming years will be from rf currents rather than microwaves.
Radio frequency technology is only getting better, and even the communications that we use now were likely developed using a current technology. In fact, if you were to take a quick history lesson, you would find that the first radio transmissions took place via rf currents transmitting information from one radio station to another. As the technology moved forward and frequency hopping was applied, the options for communication improved greatly as more efficient signal carriers were discovered. Now, instead of needing many stations to broadcast a message, it is possible to communicate with people all over the world by using only a single frequency.
A great example of this is the National Cellphone Number Search System. With a simple handheld device, you can search a cellular directory and find out who owns a certain phone number. You can also find out a great deal of information about who owns a particular cell phone or even where they live. All this is accomplished simply by using a radio frequency identification (RFID) reader and a handheld gps.