3D Printed 5-Order Butterworth Passive Filter with Conical Inductors for RF Broadband Applications

This paper presents a full-3D manufacturing technology for RF electronics based on stereolitography 3D-printing and a metallization process that combines electroless coating with electroplating. To illustrate the quality of the fabrication process, a 5th-order passive low-pass filter based on Butterworth topology has been designed, fabricated and tested. Conical inductors, to enlarge the bandwidth, and 3D capacitors have been used in the design. The results obtained are in very good agreement with theory and FEM simulations.