Patent ID: 8854131

Claim:
A method for bidirectional signal propagation comprising: sensing a voltage level of a first signal at a first port with a threshold detector; coupling the first port to an output of a variable gain amplifier with a first solid state switch if the voltage level of the first signal is less than a threshold voltage, whereby a second signal applied to a second port coupled to an input of the variable gain amplifier is propagated in a first direction from the second port to the first port; bypassing the variable gain amplifier with a second solid state switch if the voltage level of the first signal is greater than the threshold voltage such that the first signal is propagated in a second direction from the first port to the second port, wherein the second port is coupled to the input of the variable gain amplifier by a third solid state switch which is opened when the amplifier is bypassed by the second solid state switch; and controlling the gain of the variable gain amplifier with a control signal comprising a ramp signal that is related to the voltage level of the first signal.