A new filter design technique based on transformed frequency variation is described in this paper. This technique is developed for the purpose of inpro-ving numerical conditions and solving the approximation problem

in the filter design. The paper discusses the application of this technique to each stage of the synthesis process and develops a complete CAD programme for equiripple lowpass and highpass filters. With the desired attenuation-frequency characteristic inputted

the computer can give data output defining the network structure

attenuation-frequency characteristic and delay characteristic as required.