implementation of a fourth-order compact quasi-elliptic substrate integrated waveguide filter in c-band

Substrate integrated waveguide (siw) technology by application of the planar construction process obtains a catchy means for integrating planar and nonplanar circuits. further, it is hard to realize the negative coupling needed to create a compact quasi-elliptic bandpass filter based on a single-layered siw structure. the presented work proposes a specific planar and negative coupling configuration that provides two transmission zeroes at 5.03 ghz and 6.26 ghz. this article presents a fourth-order quasi-elliptic filter. the proposed filter is also wide-band. this structure is implemented in siw knowledge. the siw filter has a central frequency of 5.5 ghz. the perfect bandwidth is 0.7 ghz. it is realized on a single-layer substrate from rogers ro4003. the thickness of the substrate is considered as 0.508 mm. the measured outcomes of this filter, which show an excellent selectivity, and a low insertion loss of about 1.9 db, agree suitably with simulation results. the designed filter's innovation provides these features: compact, low cost, wide-band, good selectivity, low insertion loss, and agreement between simulation and fabrication.