Amplitude Modulation:
- It is the earliest modulation technique used to transmit voice by radio.
- This type of modulation technique is used in electronic communication.
- In this the amplitude of carrier signal varies in accordance with message signal and frequency, phase are remains constant.
- Its range is 540-1600KHz.
Uses:
- It is used in computer modems.
- It is used in VHF aircraft radio and portable two way radio.
Advantages:
- Low bandwidth.
- Transmitted to large distance.
- AM signals are reflected back to earth from Ionosphere layer.
- More number of signals can be transmitted.
Disadvantages:
- Weak signaling quality compare to FM.
- Noisy
- Power usage is high.
Frequency Modulation:
- In the frequency of carrier signal varies in accordance with message signal and amplitude, phase are remains constant.
- Its range is 88-108MHz.
Uses:
- It is used in radar, telemetry, seismic prospecting and monitoring newborns for seizures via EEG.. etc.
- It is mainly used for broadcasting music and speech, magnetic tape recording systems, two way radio systems and video transmission systems.
Advantages:
- Noise reduction.
- Improve system fidelity.
- More efficient use of power.
- No limit for depth of modulation.
Disadvantages:
- Increase band width.
- Use of more complex circuit.
- Less area is covered.
Video for AM vs FM:
My notes images:
