Design and Analysis of Miniaturized SIW Filter Loaded with Improved CSRR Structures

This work seeks to contribute to the ongoing advances in this field, aiming to address challenges and explore the potential of these resonant metamaterial structures for future microwave devices and systems. A lot of attention has been paid recently to Split-Ring Resonators (SRRs) and Complementary Split-Ring Resonators (CSRRs) due to their special electromagnetic characteristics, such as negative permeability and negative permittivity, which make them interesting options for cutting-edge microwave devices. The improved CSRR unit can be easily integrated on the surface of the SIW, making it an ideal candidate for the design of compact SIW filters. In this paper, an improved CSRR-loaded SIW filter is designed and analyzed based on its equivalent lumped parameter model. A filter with a center frequency at 22.6 GHz is designed. Several transmission zeros (TZs) are also realized to improve the skirt selectivity of the filter. The design process involves theoretical analysis and electromagnetic simulations to optimize the dimensions of the CSRR resonators to achieve the desired filter characteristics. The efficiency of the suggested enhanced CSRR-loaded SIW filter is confirmed by the good match between the simulated and measured findings. The increased CSRR-loaded SIW filter's ability to be miniaturized and operate better in sophisticated microwave applications is demonstrated by its successful implementation. This research paves the way for further advancements in SIW filter design and implementation, leveraging the advantages of CSRRs in achieving miniaturization and enhanced filter performance in the higher frequency ranges.