2. Modulate the radio waves: The radio waves generated by the oscillator are modulated in order to carry the message. Modulation is the process of varying one or more properties of the radio waves in accordance with the message being sent. There are three main types of modulation:
- Amplitude modulation (AM): AM modulates the amplitude (strength) of the radio waves.
- Frequency modulation (FM): FM modulates the frequency of the radio waves.
- Phase modulation (PM): PM modulates the phase of the radio waves.
3. Transmit the radio waves: The modulated radio waves are then transmitted through the antenna, which converts the electrical signals into electromagnetic waves that propagate through space.
4. Receive the radio waves: At the receiving end, an antenna receives the radio waves and converts them back into electrical signals.
5. Demodulate the radio waves: The demodulator circuit extracts the original message from the modulated radio waves. The type of demodulator used depends on the type of modulation that was used.
6. Amplify the message: The demodulated message is usually very weak, so it is amplified using an amplifier circuit before being passed on to the receiver.