Function generator for radar stc circuits

Claim 1

IN A RADAR SYSTEM IN WHICH SHORT PULSES OF HIGH FREQUENCY ENERGY ARE PERIODICALLY RADIATED AND IN WHICH ECHOES OF SAID PULSES ARE RECEIVED IN A RECEIVER THE GAIN OF WHICH MAY BE CONTROLLED BY AN APPLIED GAIN CONTROL VOLTAGE, APPARATUS FOR CONTROLLING THE GAIN OF SAID RECEIVER AS A DIRECT PREDETERMINED FUNCTION OF RANGE, COMPRISING: A CAPACITOR; A SOURCE OF DIRECT VOLTAGE; A CHARGING CIRCUIT CONNECTING SAID SOURCE TO SAID CAPACITOR FOR CHARGING SAID CAPACITOR TO A PREDETERMINED VOLTAGE; A PAIR OF DISCHARGE CIRCUITS CONNECTED IN PARALLEL ACROSS SAID CAPACITOR, SAID CIRCUITS PROVIDING DIFFERENT DISCHARGE TIME CONSTANTS; MEANS SYNCHRONIZED WITH SAID RADIATED PULSES FOR OPENING SAID CHARGING CIRCUIT FOLLOWING EACH RADIATED PULSE FOR AN INTERVAL LESS THAN THE REPETITION PERIOD OF SAID PULSES; A ZENER DIODE CONNECTED AS A SERIES ELEMENT IN THE DISCHARGE CIRCUIT HAVING THE SHORTER TIME CONSTANT, SAID ZENER DIODE HAVING A BREAKDOWN VOLTAGE LYING BETWEEN THE CAPACITOR VOLTAGES AT THE BEGINNING AND THE END OF SAID INTERVAL; AND MEANS FOR APPLYING THE VOLTAGE ACROSS SAID CAPACITOR TO SAID RECEIVER AS A GAIN CONTROL VOLTAGE.