A NUMERICAL METHOD IS PROPOSED FOR CALCULATING THE INPUT CIRCUIT FUNCTION FROM REAL AND IMAGINARY COMPONENTS OF THE IMMITANCE, SPECIFIED IN A LIMITED RANGE OF FREQUENCIES (IN THE FORM OF TABLES OR GRAPHS). THE MAXIMUM CAPABILITIES OF PASSIVE RLC-CIRCUITS ARE INVESTIGATED IN THE SENSE OF THEIR ABILITY TO REPRODUCE ARBITRARY CURVES OF THE IMMITANCE COMPONENTS. EXAMPLES OF COMPUTER-AIDED CIRCUIT SYNTHESIS ARE GIVEN.