Modulated input signal filter

摘要

A modulated input signal is filtered to reduce noise. The state of the input signal controls the state of a switch. Depending upon its state, the switch connects one of two circuits to a gate. The gate receives the input signal and it passes or blocks the signal depending upon the state of the signal received from the switched circuits. When it is passing the input signal, the output of the gate is equivalent to the input signal. When it is blocking the input signal, the output of the gate is set to a default state. The default state is independent of the input signal. One of the switched circuits gradually modifies the signal provided by the gate to allow the input signal to pass through. The other switched circuit gradually modifies the signal provided to the gate to block the input signal.