Deep Dive: E7E10
The correct answer is A: By rectification and filtering of RF signals. How does a diode envelope detector function is by rectification and filtering of RF signals. Diode rectifies RF, filter extracts audio. For amateur radio operators, this is important for demodulation. Understanding this helps when working with AM detectors.
Why Other Answers Are Wrong
Option B: Incorrect. By breakdown of Zener voltage isn't how envelope detector works - envelope detector rectifies and filters. Zener breakdown isn't how it works. Option C: Incorrect. By mixing signals with noise in transition region isn't how envelope detector works - envelope detector rectifies and filters. Mixing with noise isn't how it works. Option D: Incorrect. By sensing change of reactance with frequency isn't how envelope detector works - envelope detector rectifies and filters. Reactance change isn't how it works.
Exam Tip
Diode envelope detector function = by rectification and filtering of RF signals. Think 'D'iode 'E'nvelope 'D'etector = 'D'emodulates 'E'nvelope (rectify and filter). Diode rectifies RF, filter extracts audio. Not Zener breakdown, not mixing with noise, not reactance change - just rectification and filtering.
Memory Aid
Diode envelope detector function = by rectification and filtering of RF signals. Think 'D'iode 'E'nvelope = 'R'ectify and 'F'ilter. Diode rectifies RF, filter extracts audio. Important for demodulation.
Real-World Example
A diode envelope detector: It functions by rectification and filtering of RF signals. The diode rectifies the RF signal, and a filter extracts the audio envelope. This is how it functions - rectification and filtering.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E7E
Reference: 2024-2028 Question Pool · E7 - Practical Circuits
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E7E topic.