Substrate Integrated Waveguide Cross-Coupled Bandpass Filter With Wide-Stopband

This paper presents a fourth-order cross-coupled bandpass filter with wide-stopband designed using substrate integrated waveguide (SIW) cavities. The fundamental TE101 mode of the cavity is utilized to constitute the passband. The cross-coupling topology is adopted to realize two transmission zeros (TZs) at both sides of the passband which improve the filter selectivity. Moreover, the passband generated by the first higher-order mode of the cavity TE102 is suppressed by minimizing its coupling in order to obtain wide-stopband rejection. The designed filter is fabricated and measured in order to validate the present approach. The simulation and measurement results show an acceptable agreement between them.