What is an advantage of amplitude modulation?

• A. It is prone to noise
• B. It is relatively cheap and easy to implement
• C. It has good spectrum efficiency
• D. It requires advanced hardware

Answer: (B)

An AM signal offers the advantage of simple, inexpensive hardware. Because the information is carried in the carrier’s amplitude, you can generate and modulate the carrier with very basic analog circuitry—just a carrier oscillator, a straightforward modulator stage, and a power amplifier. At the receiving end, recovery is often done with an envelope detector (a diode and a simple RC filter), which doesn’t require complex synchronization or advanced processing. This combination makes AM easy to design, build, and maintain, keeping costs down compared to more complex modulation schemes. While other methods can offer better noise performance or spectral efficiency, AM’s key benefit in practice is its low hardware complexity and cost.