Active learning method for designing miniaturized waveguide filters loaded by broadside-coupled split ring resonators

This paper focuses on the design and fabrication of miniaturized rectangular waveguide bandpass filters which are loaded by broadside-coupled split ring resonators. The conventional coupling matrix approach is proposed to design these kinds of filters. Also the time consuming process of coupling factor computation which is based on full wave simulations is replaced by a very fast and accurate fuzzy based method which is named active learning method (ALM). Therefore coupling factor computation time decreases to several minutes instead of several hours in the conventional approach while keeping accuracy. Using the ALM-based extracted coupling factor surfaces two Chebychev bandpass filters were designed and fabricated. A very good agreement between simulation and measurement results shows the accuracy of the proposed method.