Balanced drive for semiconductor diode attenuator in automatic gain controlled amplifier

Claim 1

IN COMBINATION WITH A SIGNAL TRANSMISSION LINE CONNECTED BETWEEN A SOURCE AND A LOAD, MEANS SHUNTING SAID LINE FOR VARIABLY ATTENUATING THE SIGNALS ON SAID LINE COMPRISING: (A) A RESISTOR CONNECTED IN SERIES WITH SAID LINE BETWEEN SAID SOURCE AND SAID LOAD, (B) A PAIR OF SERIES-CONNECTED SEMICONDUCTOR DIODES POLED IN THE SAME DIRECTION, THE JUNCTURE ADJACENT TERMINALS OF SAID PAIR OF DIODES BEING CONNECTED TO SAID LINE AT A POINT BETWEEN SAID RESISTOR AND SAID LOAD, (C) A PAIR OF LIKE RESISTORS CONNECTED IN SERIES BETWEEN THE REMAINING TERMINALS OF SAID PAIR OF DIODES, (D) FIRST MEANS HAVING AN OUTPUT CONNECTED TO THE REMAINING TERMINAL OF ONE OF SAID PAIR OF DIODES AND ADAPTED TO APPLY A FIRST VOLTAGE THERETO HAVING A PREDETERMINED MAGNITUDE AND POLARITY, (E) AND SECOND MEANS HAVING AN OUTPUT CONNECTED TO THE REMAINING TERMINAL OF THE OTHER OF SAID PAIR OF DIODES AND ADAPTED TO APPLY A SECOND VOLTAGE THERETO HAVING A MAGNITUDE EQUAL TO SAID FIRST VOLTAGE BUT OF OPPOSITE POLARITY, SAID SECOND MEANS HAVING AN INPUT CONNECTED TO SAID JUNCTURE OF SAID PAIR OF LIKE RESISTORS AND BEING RESPONSIVE TO THE POTENTIAL THEREON.