Synthesis of Vertical Interdigital Filters Using Multilayered Technologies

Taking advantage of multilayer technologies, a vertical evolution of the interdigital topology is proposed with its associated synthesis method. In order to validate this filter topology, a 4-pole filter, centered at 10 GHz, and an 11-pole filter, centered at 6 GHz, have been designed and fabricated using low-temperature co-fired ceramic (LTCC) technology. Two other multipole filters have also been designed showing a large surface reduction with respect to equivalent interdigital filters. LTCC technology has been chosen for fabricating the filters, but the proposed topology can also be implemented with other multilayer technologies.