What is a product detector?

A product detector is a device that demodulates signals using a mixing process combined with a locally generated carrier signal. This technique is integral to the process of demodulation in communication systems, where the incoming modulated signal is multiplied by a local oscillator frequency. The result of this mixing process produces new frequency components, including the baseband signal that contains the original information.

This method is efficient for recovering signals that have been modulated using various schemes, particularly for amplitude modulation (AM) and single sideband (SSB) signals. The product detector effectively extracts the desired information from the carrier wave, working by producing the sum and difference frequencies of the incoming signal and the local oscillator. Importantly, this allows for versatile demodulation capabilities, meaning it can be applied to a variety of modulation schemes beyond just AM.

The other options either misrepresent the function of a product detector or apply to different types of equipment or processes. While a product detector does not solely amplify RF signals without distortion, or isolate specific frequencies from a multi-signal environment, it is primarily recognized for its mixing capability to demodulate signals efficiently.