Transmitter:
1. Signal Generation: Radio stations generate an electrical signal that represents the audio or data to be transmitted. This signal is created by microphones, music players, or other sound sources.
2. Modulation: The audio signal is modulated onto a carrier wave, which is a higher-frequency signal. This process alters the carrier wave's amplitude (AM radio) or frequency (FM radio) based on the amplitude or frequency of the audio signal.
3. Transmitting Antenna: The modulated carrier wave is sent to a transmitting antenna. The antenna converts the electrical signal into electromagnetic waves (radio waves) and radiates them into the air.
Receiver:
1. Receiving Antenna: The receiving antenna captures the electromagnetic waves (radio waves) transmitted by the broadcasting station.
2. Amplification: The weak radio waves picked up by the antenna are amplified to strengthen the signal.
3. Demodulation: The receiver uses a process called demodulation to extract the original audio signal from the modulated carrier wave. In AM radio, the amplitude variations are detected, while in FM radio, the frequency variations are decoded.
4. Audio Output: The recovered audio signal is then sent to a speaker or headphones, converting the electrical signal back into sound waves that we can hear.
By tuning the receiver to the same frequency as the transmitting station, the radio picks up and decodes the specific radio signal, allowing us to listen to the intended audio content. Additionally, radios may include other features like frequency selection, volume control, and signal strength indicators for better user experience and reception.