- The radio signal is used for transmitting and receiving electromagnetic waves.
- It is an electronic device that generated signals artificially by using the transmitter, which is connected to an antenna that radiates the waves.
- The radio receiver is connected by another antenna to receive the signal.
- It is very widely used in modern technology for fixed and mobile radio communication, broadcasting, radar and radio navigation systems, communications satellites, wireless computer networks, and many other applications.
- The radio signal is used to send a signal to astronauts, and establish Wi-Fi connections, for cellular communication.
- The radio signal and radio waves have both electric and magnetic components.
- This is the same as light rays, ultraviolet and infrared. The only difference is in the wavelength of the waves.
- Radio waves are a type of electromagnetic radiation with frequencies ranging from 300 GHz to as low as 3kHz, and wavelengths ranging from 1 millimeter (0.039 inches) to 100 kilometers (62 miles).
- A wavelength is defined by the distance between two consecutive locations, such as crests or zero crossings, that are in phase with each other.
- The frequency is the number of oscillations per unit of time.
- The wavelength is inversely proportional to the frequency, i.e. the higher the frequency of a wave, the shorter its wavelength, and vice versa.
- 3kHz to 300 GHz is the range of radio frequencies. See below for an illustration of high and low radio frequencies.
Speed of a Radio Signal
- The speed of the electromagnetic wave and light wave is the same. The time is taken to be 3 x 10 8metres a second but a more exact figure is 299 792 500 meters a second in a vacuum.
Wavelength and Frequency Conversion
- A radio wave’s wavelength, frequency, and speed are all interconnected.
- It is fairly simple to determine the wavelength of a signal if its frequency is known because the speed is essentially the same whether the signal is traveling in space or the atmosphere.
- Conversely, if the wavelength is known, the frequency can be computed. The calculation is quite easy.
v = l x f
where
v =the velocity of the radio wave in meters per second (normally taken as 3 x 10 8m/s
l = the wavelength in meters
f =the frequency in Hertz
Frequency and Wavelength
- The radio wave has several characteristics that can be measured.
- The wavelength was one of the first to be measured. Initially, the wavelength was employed to determine the position of radio stations on a radio dial.
- For instance, the BBC once had a transmitter that broadcast on a 1500-meter wavelength.
- The distance between a place on one wave and the same point on the following is known as the wavelength of a radio wave.
- The peak is one of the most obvious spots to use as a reference because it is so easy to spot, but any point is valid as long as the same point is picked for each wave.
- The pond analogy can be used to explain the frequency.
- It is the number of times the wave rises and falls in a specific amount of time at a specific location in the pond.
- The Hertz, which is used to measure frequency, is equal to one cycle or wave every second.
- The standard prefixes of kilo (kiloHertz, kHz) for a thousand Hertz, Mega (MegaHertz, MHz) for a million Hertz, and Giga (GigaHertz, GHz) for a thousand million Hertz are frequently used since the frequencies encountered can be very high.