A compact SIW metamaterial coupled gap zeroth order bandpass filter with two transmission zeros

This paper presents a new compact metamaterial bandpass filter based on coupled gap composite right left handed transmission line resonator using substrate integrated waveguide to become low loss. The filter size is only 20 × 15 mm
²
which is (0.61 λ
g
) at center frequency (6.8 GHz). Moreover, the filter was designed to demonstrate a zeroth order at 6.8 GHz with two transmission zeros; the first one is at −44 dB and the second one is close to −50 dB in a high selective characteristics (less than only 300 MHz from centre frequency). The paper exhibits the equivalent circuit model, 3D full wave simulation and fabrication measurement results. Good agreement between the presented data is achieved.