Which type of detector is used for demodulating SSB signals?

Single Sideband (SSB) signals are essentially AM signals with the carrier and one sideband removed. Because the carrier is missing, a simple envelope detector cannot recover the audio. Instead, a product detector is used to demodulate the signal. A product detector works by taking the incoming SSB signal and mixing (multiplying) it with a locally generated carrier from a Beat Frequency Oscillator (BFO). The "product" of these two signals yields the original audio frequencies, mathematically shifting the RF sideband back down to the audio baseband. Discriminators and phase detectors are typically used for frequency or phase modulation (FM/PM) demodulation, not for SSB. Therefore, the product detector is the specific circuit designed to insert the missing carrier and extract the audio from an SSB transmission.