Why do we need angle modulation?

Angle modulation, including frequency modulation (FM) and phase modulation (PM), is used in telecommunications for a number of reasons:

1. Resistance to noise: FM and PM are both more resistant to noise than amplitude modulation (AM), which makes them suitable for high-fidelity audio transmission and other applications where signal quality is important.

2. Efficient use of bandwidth: PM in particular can transmit more information per unit of bandwidth than other modulation techniques, which makes it useful for digital communication systems.

3. Compatibility with existing systems: FM is widely used in radio broadcasting, and many existing receivers are designed to receive FM signals. Using FM for new applications can therefore take advantage of existing infrastructure and equipment.

 4. Versatility: Angle modulation can be used to transmit many different types of signals, including audio, video, and data. FM and PM can be used in both analog and digital communication systems.

5. Security: Angle modulation can be used to transmit information in a secure manner, by using encryption techniques to encode the modulating signal.

Overall, angle modulation is a versatile and reliable technique for transmitting information over a communication channel, and it has many advantages over other modulation techniques in certain applications.