Design, manufacture and characterization of compact filter assemblies for radiofrequency applications

Abstract

This paper presents the use of additive manufacturing in the design and fabrication of a non-planar fully 3D-printed low-pass filter. The process implements stereolithographic 3D printing and copper electroplating to produce the necessary parts and their casing. The filter we produce acts as a demonstrator: we present the possibility of constructing building blocks and combining different elements into a full assembly for system integration. We introduce the “drop-and-screw” concept, which is implemented to mount the parts into a single connectorized assembly without the need for welding. The method we propose may be suitable for building other components by simply changing the building blocks. We pay special attention to the design of the constituent parts of the filter (a 3D conical inductor and a 3D capacitor), exploring new geometries to reduce the size of the final filter prototypes. The results demonstrate the potential of additive manufacturing in the construction of high-performance RF components and assemblies, and we present a modular prototype with a high degree of reconfigurability and multifunctionality.