Voltage controlled temperature stabi-lized variable gain circuits

Claim 1

IN A TRANSFER QUADRIPOLE AN ATTENUATING ELEMENT WITH THREE TERMINALS, SUBSTANTIALLY INSENSITIVE TO TEMPERATURE VARIATIONS, OF WHICH THE DEGREE OF ATTENUATION IS CONTROLLED BY AN ADJUSTABLE CONTROL POTENTIAL DIFFERENCE, COMPRISING A NEUTRAL POINT AT A REFERENCE POTENTIAL, AT LEAST ONE CHAIN OF TWO ASSOCIATED GROUPS EACH CONSISTING OF 2N DIODES CONNECTED IN SERIES WITH THE SAME ORIENTATION IN EACH GROUP, N BEING AN INTEGER, THE TWO ASSOCIATED GROUPS OF DIODES OF A CHAIN HAVING A COMMON TERMINAL AND TWO NON-COMMON TERMINALS BEING ALL AT THE SAME ALTERNATING POTENTIAL AS SAID NEUTRAL POINT AND BEING SO ASSOCIATED THAT THE ORIENTATION OF THE DIODES IN ONE OF SAID TWO GROUPS IS OPPOSITE TO THE ORIENTATION OF THE DIODES IN THE OTHER GROUP WITH RESPET TO SAID COMMON TERMINALS, ONE DIRECT CURRENT SOURCE ASSOCIATED TO EACH CHAIN OF DIODES HAVING TWO TERMINALS, A FIRST OF SAID TERMINALS BEING CONNECTED TO SAID NEUTRAL POINT AND A RESISTOR CONNECTING THE SECOND OF SAID TERMINALS TO THE COMMON TERMINAL OF THE TWO GROUPS OF DIODES OF SAID CHAIN WHEREBY SAID TWO GROUPS OF DIODES ARE PERMANENTLY FED BY DIRECT CURRENTS, A CONTROL VOLTAGE SOURCE PRODUCING A CONTROL POTENTIAL DIFFERENCE DISTRIBUTED IN TWO FRACTIONS EACH APPLIED RESPECTIVELY BETWEEN ONE NON-COMMON TERMINAL OF A GROUP OF DIODES AND A POINT AT THE SAME ALTERNATING POTENTIAL AS THE NEUTRAL POINT, THE THREE TERMINALS OF THE ATTENUATOR ELEMENT COMPRISING A FIRST TERMINAL AT THE SAME ALTERNATING POTENTIAL AS THE NEUTRAL POINT, A SECOND TERMINAL AT THE SAME ALTERNATING POTENTIAL AS A JUNCTION POINT BETWEEN THE NTH AND N+1TH OF A GROUP RECKONING FROM ONE TERMINAL OF SAID GROUP AND A THIRD TERMINAL AT THE SAME ALTERNATING POTENTIAL AS A JUNCTION POINT BETWEEN THE NTH AND N+1TH DIODE OF ANOTHER GROUP, RECKONING FROM ONE TERMINAL OF SAID GROUP.