Synthesis and Design of a Compact Electrically-Coupled Combline Filter with Multi-Sections Resonator
Résumé
In this paper, a novel filter topology called Electrically-Coupled Combline (ECC) is proposed. The main asset of this topology compared to the standard Magnetic Coupling Combline (MCC) filter is that it is fully achievable with a planar technology. The synthesis of the filter is introduced and a practical implementation on a third-order filter is presented. To increase the electrical couplings to levels needed by this topology to achieved the desired relative passband (40%), the proposed Electrically Coupled Combline filter uses a Multi-Section line. Finally, the measurements are shown, and they appear to be consistent with the simulated results, exhibiting high compactness and good electrical performances. A third-order filter working at 125 MHz with a relative passband of 40% is finally presented to demonstrate the interest of this novel topology.