Analog Modulation & It’s types

Analog modulation is further divided into three types:

 Amplitude modulation.

 Frequency modulation.

 Phase modulation.

Amplitude Modulation:

Amplitude modulation is a process by which the wave signal is transmitted by modulating the amplitude of the signal. Amplitude modulation or AM as it is often called, is a form of modulation used for radio transmissions for broadcasting and two-way radio communication applications. Although one of the earliest used forms of modulation it is still used today, mainly for long, medium, and short-wave broadcasting and for some aeronautical point to point communications. Currently, this technique is used in many areas of communication such as in portable two-way radios, citizens band radio, VHF aircraft radio and in modems for computers. Amplitude modulation is also used to mention the mediumwave AM radio broadcasting.

One of the key reasons for the use of amplitude modulation was its ease of use. The system simply required the carrier amplitude to be modulated, but more usefully the detector required in the receiver could be a simple diode-based circuit. This meant that AM radios did not need complicated demodulators and costs were reduced - a key requirement for widespread use of radio technology, especially in the early days of radio when ICs were not available.

 

In general, amplitude modulation definition is given as a type of modulation where the amplitude of the carrier wave is varied in some proportion with respect to the modulating data or the signal.

Types of Amplitude Modulation:

o Double sideband-suppressed carrier modulation (DSB-SC).

o Single Sideband Modulation (SSB).

o Vestigial Sideband Modulation (VSB).

Advantages of Amplitude Modulation:

• Easier to implement.

• Simple demodulation circuit.

• Cheap receiver.

Disadvantages of Amplitude Modulation:

• AM signal is not efficient in terms of power usages.

• Use of bandwidth not efficient.

• Noise interference is high.