Integrated resistance-capacitance semiconductor frequency selective filter

Claim 1

A FREQUENCY SELECTIVE R.C. FILTER COMPRISING AN INTEGRATED SEMICONDUCTOR DEVICE HAVING A FIRST REGION OF SEMICONDUCTOR MATERIAL OF GIVEN TYPE CONDUCTIVITY, A REGION OF SEMICONDUCTOR MATERIAL OF OPPOSITE TYPE CONDUCTIVITY IN CONTACT WITH SAID GIVEN TYPE CONDUCTIVITY MATERIAL TO THEREBY FORM A FIRST P-N CAPACITANCE JUNCTION THEREWITH, A SECOND REGION OF SEMICONDUCTOR MATERIAL OF GIVEN TYPE CONDUCTIVITY ALSO IN CONTACT WITH SAID OPPOSITE TYPE CONDUCTIVITY MATERIAL TO THEREBY FORM A SECOND CAPACITANCE P-N JUNCTION THEREWITH, A FILM OF CONDUCTIVE MATERIAL DISPOSED ON A SURFACE OF EACH REGION OF SAID GIVEN TUPE CONDUCTIVITY MATERIAL, WHEREBY A CAPACITOR IS FORMED BETWEEN SAID REGION OF OPPOSITE TYPE CONDUCTIVITY AND EACH OF SAID FILMS, MEANS ELECTRICALLY CONNECTING SAID CONDUCTIVE FILMS TO ONE ANOTHER TO THEREBY CONNECT SAID CAPACITORS IN PARALLEL RELATIONSHIP TO PROVIDE A CAPACITANCE VALUE APPROXIMATELY TWICE THE NORMAL VALUE ACHIEVED WITHOUT SAID CONDUCTIVE FILMS, A PAIR OF TERMINALS, SAID TERMINALS BEING IN CONTACT WITH SAID REGION OF OPPOSITE TYPE CONDUCTIVITY AT SPACED POINTS THEREON, AND A THIRD TERMINAL CONNECTED TO ONE OF SAID REGIONS OF GIVEN TYPE CONDUCTIVITY, WHEREBY AN ELECTRICAL CIRCUIT IS FORMED BETWEEN SAID TERMINALS WHEREIN THE SELECTED FREQUENCY IS REDUCED TO APPROXIMATELY ONE-HALF THE NORMAL VALUE.