Radio Waves

How Radio Waves Are Produced

Radio waves are generated by the accelerated motion of charges — specifically, electrons moving back and forth in a conducting wire (like an antenna). Whenever a charge accelerates, it produces an electromagnetic wave. In a wire, the alternating current forces electrons to oscillate, creating a changing electric field, which in turn generates a changing magnetic field. These self-sustaining fields propagate outward as a radio wave.

Frequency Bands and Their Uses

Radio waves span a wide range of frequencies, from about 500 kHz to 1000 MHz. Different frequency bands are allocated for specific communication systems:

• AM (Amplitude Modulated) band: 530 kHz to 1710 kHz — used for standard radio broadcasting.
• Short wave bands: Frequencies up to 54 MHz — used for long-distance communication.
• TV waves: 54 MHz to 890 MHz — used for television broadcasting. …