Sensitivity analysis of a 3-D printed low-cost compact waveguide low-pass filter

A sensitivity analysis of a very compact low-loss waveguide low-pass filter and its classical counterpart, a waffle-iron filter, is shown in this paper. The tolerance analysis of the previous filter design methods will be analyzed, compared, and discussed from the predicted manufacturing yield point of view. It is found that the presented filter allows relaxed fabrication tolerances which let us manufacture it using a low-cost 3-D printer. Finally, in order to demonstrate the robustness of the design method, a lightweight prototype manufactured by stereo-lithography (SLA) 3-D printing in photo-polymer resin and then coated with copper is shown. The measured frequency response shows an excellent agreement with the simulations.