What is Radio Spectrum? And how does it Works?
Radio spectrum is defined as the region of the electromagnetic spectrum spanning the radio frequency range. At every point in space, there is always something we call the ‘electric field’. It is a tiny vector, a quantity with a fixed magnitude and direction. And if you want to measure it, just place an electron at rest at that point, and just watch it start moving. The direction and size of its acceleration is proportional to the electric field.
Generally, if you watch closely enough, you will see that electron move quickly back and forth. This is because the electric field doesn’t sit there; we all are enclosed by an extraordinary superposition of all kinds of electromagnetic waves, pushing with different amplitudes and directions and frequencies.
How the Radio Spectrum Works?
You might have heard about ‘AM radio’ and ‘FM radio’, ‘VHF’ and ‘UHF’ television, and so on. But do you know the difference between them?
A radio wave is an electromagnetic wave propagated by an antenna. Radio waves come with different frequencies, and by tuning a radio receiver to a specific frequency you can pick up a particular signal.
When you listen to a radio station and the announcer says, ‘You are listening to 91.5 FM’. Here, the announcer means that you are listening to a radio station broadcasting an FM radio signal at a frequency of 91.5 MHz. Megahertz means millions of cycles per second, so it clearly means that the transmitter at the radio station is oscillating at a frequency of 91,500,000 cycles per second. Your frequency radio can tune in to that specific frequency and provides you a clear reception of that particular station. All FM radio stations transmit in a band of frequencies between 99-109 MHz. This band of the radio spectrum is used for no other purpose but the FM radio broadcasts.
In the very same way, AM radio is limited to a band of 535 kilohertz to 1,700 kilohertz. So an AM radio station that speaks, ‘This is AM 680 WPTF’ means that the radio station is broadcasting an AM radio signal at 680 Kilohertz and its FCC-assigned call letters are WPTF.
Radio Spectrum Frequency List
Some of the common radio frequency bands comprise of the following:
AM Radio- 535 KHz to 1.7 MHz
Short Wave Radio- Bands from 5.9 MHz to 26.1 MHz
Citizens Band Radio- 26.96 MHz to 27.41 MHz
Television Stations- 54 to 88 MHz for channels 2 through 6
FM Radio- 88 MHz TO 108 MHz.
Television Stations- 174 to 220 MHZ for channels 7 through 13
What is worth noticeable is that every wireless technology comes with its own little band and there are almost hundreds of them.
