AdvancedA-006-004-002
What does a product detector do?
C
Answer
Propagation and operating practice
Type
A
It amplifies and narrows band-pass frequencies
B
It provides local oscillations for input to a mixer
C
It mixes an incoming signal with a locally generated carrier
D
It detects cross-modulation products
Answer Notes
A product detector is a specialized type of mixer used in radio receivers specifically to demodulate Single Sideband (SSB) and Continuous Wave (CW) signals. It works by multiplying, or 'mixing', the incoming Intermediate Frequency (IF) signal with an unmodulated local carrier generated by the receiver's Beat Frequency Oscillator (BFO).
The mathematical output of this mixing process is the 'product' of the two signals, which yields the recovered baseband audio signal. This is why it is called a product detector.
Distractors like 'detects cross-modulation products' play on the word 'product' but actually describe a form of interference or distortion, not the intended demodulation function of this circuit.
Previous · A-006-004-001
What audio shaping network is added at an FM receiver to restore proportionally attenuated lower audio frequencies?
Next · A-006-004-003
Distortion in a receiver that only affects strong signals usually indicates a defect in or mis-adjustment of the: