Impedances Call the Tune in Filter Design

This paper presents a simple graphical method for designing low pass filters in systems with mismatched load and source impedances. The insertion loss equations for these networks are expressed in terms of three variables which facilitate the development of a simple and rapid design technique. Nomographs and design charts, based on the results of a digital computer study of the equations, are presented for pi and tee type networks. Instructions for the use of the charts are included through the study of practical design examples.