A Class of Biquadratic Impedances

An important class of biquadratic impedance functions consists of those functions realizable as the driving-point impedance of a network consisting of three resistors, one inductor, and one capacitor. This paper presents a study of a special subclass of these, namely, those realizable by unbalanced bridge networks composed of these five elements, one of the reactive elements being in the cross arm of the bridge. Such a network will, under suitable conditions, realize certain biquadratic impedance functions not obtainable by other networks composed of the same numbers of elements. Specific formulas are given for the synthesis of such bridge networks, together with a statement of the exact conditions upon the coefficients of the biquadratic impedance function for the physical realizability of such bridge networks.