C-Band Multilayer Bandpass Filter Using Open-Loop Resonators With Floating Metallic Patches

This letter presents a fourth-order quasi elliptic bandpass filter based on a multilayer technology. Thanks to the use of the third dimension, multilayer technology appears as a very convenient solution when a high coupling is required. This led us to use a coupling coefficient-based approach to design a very compact filter through the association of open-loop resonators and floating metallic patches to elevate coupling.