Common demodulators: AM vs FM Consider the statements: A diode is the most common device used for demodulation (detection). A discriminator is a frequency-modulation (FM) detector. Choose the correct option.

Difficulty: Easy

Correct Answer: Both the statements are true

Explanation:


Introduction / Context:
Demodulation recovers baseband information from modulated RF/IF signals. Different modulations require different detectors, but some devices are iconic: the diode detector for AM and the frequency discriminator for FM.


Given Data / Assumptions:

  • AM broadcast receivers commonly use diode envelope detectors.
  • FM broadcast receivers use discriminators (Foster–Seeley, ratio detectors) or quadrature detectors/PLLs.
  • Statements refer to common, not exclusive, usage.


Concept / Approach:

Statement 1: In consumer AM radios and many simple receivers, a diode is indeed the most common demodulating element. Statement 2: A discriminator is a classic FM detector topology converting instantaneous frequency deviations to voltage. Therefore both statements are correct as general truths.


Step-by-Step Solution:

Identify AM detection → diode envelope detector is ubiquitous.Identify FM detection → discriminator or ratio detector widely used.Conclude both statements are true in typical practice.


Verification / Alternative check:

Service manuals show diode detectors in AM paths and discriminators (or quadrature/PLL) in FM paths. Textbooks corroborate these standard choices.


Why Other Options Are Wrong:

Negating either statement contradicts widespread receiver designs; SSB demodulation generally uses product detectors, not simple diodes.


Common Pitfalls:

Assuming exclusivity: other detectors exist (synchronous AM, PLL FM), but the statements remain broadly true.


Final Answer:

Both the statements are true

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