SAMPLING GATES 1. Sampling gates are transmission circuits in which the output is the exact replica of the input during a selected time interval and is zero otherwise. 2. The time interval for the transmission of the signal is selected by an externally impressed signal called the gating signal which is usually rectangular in wave shape. 3. The sampling gates are also called transmission gates or selection circuits. 4. A gate circuit that extracts information from the input waveform only when activated by a selector pulse.