Design procedure of low cost substrate microstrip filters based on nonresonating nodes

A complete design procedure of microstrip filters with high electrical performance using non-resonating nodes (NRN) is proposed. Such design procedure, based on a distributed model with frequency dependent inverters, allows the flexible allocation of transmission zeros in order to obtain high selectivity filtering responses, as well as the reduction of their frequency sensitivity. We have successfully validated this novel strategy with the design of a high performance microstrip filter, making use of a low cost substrate (i.e. with a low dielectric constant) and considering losses effects.