A New Algorithm for the Tuning of Analog Filters

摘要

Typically, in the manufacture of electrical filters it is not practical to specify component tolerances in order to achieve one-hundred percent yield. Rather it is more cost-effective to have less stringent tolerances on the componenet values and to tune those filters which do not meet the design specifications by adjusting a subset of the component values. For example, in the manufacture of hybrid thin or thick film active filters, the capacitors are not normally trimmed, so that only the resistors in the circuit can be used to tune the filter. Furthermore, resistor trimming increases the resistance so that a carefully designed tuning scheme is required. In addition, tuning can be a very expensive process, so that it is important to have a tuning algorithm which is efficient and which maximizes the yield. In this thesis a new algorithm is proposed for the tuning of analog filters. Tellegen's theorem and the adjoint network concept are used to relate large changes in a set of tuning elements to desired voltage changes in the manufactured filter.