**8. Conclusions**

The metamaterials can be applied to enhance bandwidth, create a compact structure or multifrequency bands, etc. In this chapter, various compact and selective CSRR integrated SIW bandpass filters have been analyzed, demonstrating their

performance. To apply metamaterials, the first step is to design their unit cells, creating special metamaterial properties at the desired frequency. The size of the unit cells is calculated, simulated, and optimized using the HFSS software. First, three edge-coupled CSRR (EC-CSRR) BPFs have been analyzed for the design and performance. Then two broadside-coupled CSRR (BC-CSRR) BPFs have been analyzed elaborately and evaluated for performance.
