Systematic Design Method of Passive Ladder Filters using a Generalised Variable

This paper focuses on the design of passive filters with a ladder structure. Based on convex optimisation, we propose an approach to extend the traditional LC-ladder filter design method to lossless passive components. To achieve this, a generalised variable T(s) is introduced, leading to a new convex formulation of the design problem. The approach is applied on an academic design problem: the design of a LC-bandpass ladder filter. This provides a first and crucial step before designing filters of practical interest.