Novel fractal-shaped bandpass filter using quarter substrate integrated waveguide resonator (QSIWR)

In this article, quarter substrate integrated waveguide resonator (QSIWR) and fractal-shaped defected structure are used to design miniaturized SIW bandpass filters. With the QSIWR, a conventional SIW filter can be reduced in size by about 75% By using the the fractal-shaped QSIWR, the two-pole bandpass filter has simple structure, compact sizes and an extra transission zero in the upper stopband.