New architectures for planar filters using split-ring resonators

An improved technique is outlined to design filters in planar configurations. The new procedure is applied to enhance the performance of some filters in planar configuration. This paper illustrates that complementary split-ring resonators (CSRRs), electrically coupled to a microstrip transmission line and split-ring resonators (SRRs) magnetically coupled to a finline structure can be applied to improve the design of such filters. For this propose, classical variants of millimeter wave filters have been analyzed. These components include microstrip low-pass filters, finline bandpass/bandstop filters and antipodal finline bandstop filters. The properties of these configurations are discussed; the experimental data are in good agreement with the simulations. The results show the usefulness and validity of the new structures as it is possible to achieve a very low insertion loss and very sharp transition bands with high rejection capabilities.