Which term describes the process of turning the negative half of a signal into positive voltages?

Which term describes the process of turning the negative half of a signal into positive voltages?

• A. Rectification
• B. Envelope
• C. Rejection/Threshold/Suppression
• D. Speckle

Answer: (A)

Rectification is the process of converting a signal that swings above and below zero into a unidirectional signal by flipping the negative portion to positive. In ultrasound receiver electronics, this turns the entire waveform into positive voltages, especially in full-wave rectification, which makes it possible to measure amplitude more easily. After rectification, the envelope of the signal is obtained by smoothing the rectified waveform with a low-pass filter, giving a smooth curve that tracks instantaneous amplitude. The other terms refer to different concepts: the envelope is the amplitude profile derived from the rectified signal; rejection/threshold/suppression involves removing unwanted parts of the signal; speckle is the granular image texture caused by coherent interference.

Rectification is the process of converting a signal that swings above and below zero into a unidirectional signal by flipping the negative portion to positive. In ultrasound receiver electronics, this turns the entire waveform into positive voltages, especially in full-wave rectification, which makes it possible to measure amplitude more easily. After rectification, the envelope of the signal is obtained by smoothing the rectified waveform with a low-pass filter, giving a smooth curve that tracks instantaneous amplitude. The other terms refer to different concepts: the envelope is the amplitude profile derived from the rectified signal; rejection/threshold/suppression involves removing unwanted parts of the signal; speckle is the granular image texture caused by coherent interference.