Design and performance analysis of 2D and 3D microwave filters using additive manufacturing techniques

Sammanfattning

This thesis investigates whether three-dimensional microwave filter structures, enabledby inkjet-based additively manufactured electronics (AME), can improve performanceor reduce the physical size of microwave filters compared to conventionaltwo-dimensional designs. A third-order Chebyshev low-pass filter was implementedas the reference design in ANSYS HFSS and compared against six three-dimensionalconfigurations, including modified ground plane structures, multi-level conductor arrangements,and geometrical variations of the signal path. The performance of eachconfiguration was evaluated using S-parameters and electric field distributions.The results show that ground plane placement proved decisive for filter behavioracross all tested configurations. Three-dimensional modifications can preserve acceptablelow-pass filter performance, but only when the return current path remainscontrolled and transitions between filter sections are kept smooth. Among the investigatedconfigurations, the most compact designs achieve reductions in planarfootprint down to 28% and 32% of the reference, respectively, at the cost of modifiedfrequency responses, while the most geometrically controlled three-dimensionalstructure maintains a cutoff frequency closely comparable to the reference filter.What matters is not simply adding a third dimension, but understanding and controllingwhat happens electromagnetically when you do.