Voltage-controlled attenuator

Claim 1

AN ATTENUATION CIRCUIT, COMPRISING: A PLURALITY OF ATTENUATION STAGES, EACH OF SAID ATTENUATION STAGES HAVING A FIRST VOLTAGE-SENSITIVE CAPACITIVE ELEMENT AND A SECOND VOLTAGE-SENSITIVE CAPACITIVE ELEMENT CONNECTED IN SERIES, EACH SUCCEEDING STAGE OF SID ATTENUATION CIRCUIT BEING CONNECTED ACROSS THE SECOND CAPACITIVE ELEMENT OF THE PROCEDING STAGE WITH THE FIRST CAPACITIVE ELEMENT OF ALL OF THE STAGES BEING CONNECTED IN SERIES, MEANS FOR APPLYING AN R.F. SIGNAL TO THE FIRST STAGE OF SAID ATTENUATION CIRCUIT, A DIRECT CURRENT POWER SUPPLY, MEANS FOR CONNECTING SAID POWER SUPPLY ACROSS THE SECOND VOLTAGESENSITIVE CAPACITIVE ELEMENT OF EACH OF SAID STAGES, MEANS CONNECTED BETWEEN SAID POWER SUPPLY AND SAID SECOND VOLTAGE-SENSITIVE CAPACITIVE ELEMENT OF EACH OF SAID STAGES FOR VARYING THE VOLTAGE APPLIED ACROSS THE SECOND VOLTAGESENSITIVE CAPACITOR, R.F. SIGNAL DECOUPLING MEANS, CONNECTED BETWEEN EACH OF SAID STAGES AND SAID POWER SUPPLY, ADDITIONAL VOLTAGE-SENSITIVE CAPACITIVE MEANS CONNECTED IN THE INPUT CIRCUIT OF SAID FIRST ATTENUATION STAGE, MEANS FOR CONNECTING SAID POWER SUPPLY ACROSS SAID ADDITIONAL CAPACITIVE MEANS, MEANS FOR VARYING THE VOLTAGE APPLIED TO SAID ADDITIONAL CAPACITIVE MEANS INVERSELY TO THE VOLTAGE APPLIED TO BE SECOND VOLTAGE-SENSITIVE CAPACITIVE ELEMENT OF EACH OF SAID STAGES TO THEREBY PROVIDE SUBSTANTIALLY CONSTANT INUT IMPEDANCE TO THE ATTENUATION CIRCUIT.