How is a product detector used?
The correct answer is D: Used in a single sideband receiver to extract the modulated signal. How a product detector is used is in a single sideband receiver to extract the modulated signal. Product detectors mix the SSB signal with a local oscillator to recover the audio. For amateur radio operators, this is how SSB receivers work. Understanding this helps when designing SSB receivers.
Exam Tip
Product detector use = in SSB receiver to extract modulated signal. Think 'P'roduct 'D'etector = 'P'roduces 'D'emodulated audio in 'S'SB receiver. Product detectors mix SSB signal with local oscillator to recover audio. Not spurious detection, not frequency multiplication, not FM filtering - just SSB demodulation.
Memory Aid
"Product detector use = in SSB receiver to extract modulated signal. Think 'P'roduct 'D'etector = 'P'roduces 'D'emodulated audio. Product detectors mix SSB signal with local oscillator to recover audio. Essential for SSB reception."
Real-World Application
An SSB receiver: The product detector mixes the incoming SSB signal with a local oscillator (BFO - Beat Frequency Oscillator). This mixing process extracts the audio from the SSB signal. Product detectors are essential for SSB reception - they're how SSB receivers recover the audio. This is the primary use of product detectors.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Product detectors aren't used in test gear to detect spurious mixing products - that's done by spectrum analyzers, not product detectors. Spurious detection isn't the use.
Option B: Incorrect. Product detectors aren't used in transmitters for frequency multiplication - that's done by multipliers, not product detectors. Frequency multiplication isn't the use.
Option C: Incorrect. Product detectors aren't used in FM receivers to filter sidebands - FM receivers use discriminators, not product detectors. FM demodulation is different.
题目解析
The correct answer is D: Used in a single sideband receiver to extract the modulated signal. How a product detector is used is in a single sideband receiver to extract the modulated signal. Product detectors mix the SSB signal with a local oscillator to recover the audio. For amateur radio operators, this is how SSB receivers work. Understanding this helps when designing SSB receivers.
考试技巧
Product detector use = in SSB receiver to extract modulated signal. Think 'P'roduct 'D'etector = 'P'roduces 'D'emodulated audio in 'S'SB receiver. Product detectors mix SSB signal with local oscillator to recover audio. Not spurious detection, not frequency multiplication, not FM filtering - just SSB demodulation.
记忆口诀
Product detector use = in SSB receiver to extract modulated signal. Think 'P'roduct 'D'etector = 'P'roduces 'D'emodulated audio. Product detectors mix SSB signal with local oscillator to recover audio. Essential for SSB reception.
实际应用示例
An SSB receiver: The product detector mixes the incoming SSB signal with a local oscillator (BFO - Beat Frequency Oscillator). This mixing process extracts the audio from the SSB signal. Product detectors are essential for SSB reception - they're how SSB receivers recover the audio. This is the primary use of product detectors.
错误选项分析
Option A: Incorrect. Product detectors aren't used in test gear to detect spurious mixing products - that's done by spectrum analyzers, not product detectors. Spurious detection isn't the use. Option B: Incorrect. Product detectors aren't used in transmitters for frequency multiplication - that's done by multipliers, not product detectors. Frequency multiplication isn't the use. Option C: Incorrect. Product detectors aren't used in FM receivers to filter sidebands - FM receivers use discriminators, not product detectors. FM demodulation is different.
知识点
Product detector, SSB receiver, Extract modulated signal, Demodulation
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.