Applicability of the superheterodyne principle For which types of modulation can a superheterodyne receiver architecture be implemented effectively?

Introduction / Context:
The superheterodyne principle uses frequency conversion to a fixed intermediate frequency, enabling stable filtering and amplification. This approach is versatile and forms the basis of most modern receivers across a wide range of modulation formats.

Given Data / Assumptions:

• Heterodyning (mixing) to a fixed IF is available.
• Appropriate demodulators for each modulation exist at IF or baseband.
• Front-end selectivity and image rejection are suitably addressed.

Concept / Approach:

Whether the incoming signal is AM, FM, or SSB, it can be downconverted to a convenient IF. After IF filtering and gain, a suitable detector is used: envelope or synchronous detectors for AM, discriminators/quadrature detectors for FM, and product detectors/BFO for SSB. Therefore, the superheterodyne framework is modulation-agnostic with the right detector and filtering.

Step-by-Step Solution:

Verification / Alternative check:

Commercial radios, scanners, and communications receivers use superhet chains for AM broadcast, FM broadcast, and SSB/HF communications alike.

Why Other Options Are Wrong:

Choosing any single modulation ignores the generality of the architecture; “none of the above” is incorrect given widespread practice.

Common Pitfalls:

Equating the detector type with the overall receiver architecture; in a superhet, detection is a final stage choice adapted to the modulation.

Final Answer:

All of the above