Algorithm for the parameters of double tuned filter

On the basis of analyzing the characteristics of the simplest and the basic type of double tuned filter, an algorithm for precisely determining its parameters is presented. Using this method, the inductances and the capacitances of the filter can be calculated from known data such as the reactive compensation capacity, the tuned frequencies and the parallel resonant frequency, etc. There are various damped types of double tuned filters, they have three pairs of tuned frequencies under the conditions of: (i) the equivalent impedance being minimum; (ii) the total reactance being zero; and (iii) when the damping resistors are out of service. Usually the tuned frequencies of condition (i) or (ii) are selected to determine parameters of the filter in the design process. The diagram for determining the parameters of damped-types is also developed.