**Abstract**

Microwave planar bandpass filters are indispensable in wireless communication systems in most applications. With miniaturization and limited spectrum, there is a great need for a compact, selective bandpass filter with a wide stopband performance. Substrate integrated waveguide (SIW) has become a potential technology for designing and developing microwave and millimeter-wave components, circuits, and systems. This chapter presents novel, compact metamaterial-based bandpass filters with improved stopbands. Several filters' design methodology and performance are evaluated using broadside-coupled complementary split-ring resonators (BC-CSRR) and edge-coupled complementary split-ring resonators (EC-CSRR) techniques. A comprehensive method to evaluate negative permittivity and permeability for designing the proposed metamaterial structure is also described. These filters have not only compact size but also a wider upper stopband resulting from bandstop resonator characteristics.

**Keywords:** substrate integrated waveguide, miniaturization, BPF, EC-CSRR, BC-CSRR
