Which modulation method is cheaper to produce and requires less power?

Which modulation method is cheaper to produce and requires less power?

• A. AM (Amplitude Modulation)
• B. FM (Frequency Modulation)
• C. PM (Phase Modulation)
• D. PWM (Pulse Width Modulation)

Answer: (A)

The main point is why a simple carrier-modulation approach tends to be cheaper and use less power: it keeps the RF chain simple. With amplitude modulation, information rides on the envelope of a carrier that stays at a fixed frequency. That lets you use straightforward analog circuitry to generate the modulated signal, and your receiver can demodulate with a simple envelope detector. There’s no need for precise frequency control, sharp phase alignment, or wideband, high-linearity power amplifiers. In contrast, frequency and phase modulation require maintaining accurate frequency or phase relationships as the information changes, plus broader bandwidths to carry the resulting sidebands. That pushes you toward more complex modulators, more precise oscillators, and often more linear (and less efficient) amplifiers, which increases both cost and power consumption. Switching-based schemes like PWM add their own switching losses and filtering needs, complicating the design further. So, because AM relies on a simple, stable carrier with an easily processed envelope, the hardware tends to be cheaper to produce and, for basic implementations, uses less power than the more complex FM, PM, or PWM approaches.

The main point is why a simple carrier-modulation approach tends to be cheaper and use less power: it keeps the RF chain simple. With amplitude modulation, information rides on the envelope of a carrier that stays at a fixed frequency. That lets you use straightforward analog circuitry to generate the modulated signal, and your receiver can demodulate with a simple envelope detector. There’s no need for precise frequency control, sharp phase alignment, or wideband, high-linearity power amplifiers.

In contrast, frequency and phase modulation require maintaining accurate frequency or phase relationships as the information changes, plus broader bandwidths to carry the resulting sidebands. That pushes you toward more complex modulators, more precise oscillators, and often more linear (and less efficient) amplifiers, which increases both cost and power consumption. Switching-based schemes like PWM add their own switching losses and filtering needs, complicating the design further.

So, because AM relies on a simple, stable carrier with an easily processed envelope, the hardware tends to be cheaper to produce and, for basic implementations, uses less power than the more complex FM, PM, or PWM approaches.