Compact Bandpass Filters And Planar Magic-T Based On One-Third Triangular Resonator Of Substrate Integrated Waveguide

Due to numerous advantages such as minimal size, high quality factor, low insertion loss, high power capability, low-cost and easy integration in standard PCB or LTCC, substrate integrated waveguides(SIWs) and substrate integrated circuits(SICs) have been widely applied to the designs of microwave, millimeter-wave circuits and systems since they were proposed in recent years. A large number of papers have studied the rectangular and circular SICs, but there is very little investigation concerning the triangular SICs. Thanks to this particular structure, the components of a triangular SIC are very compact. Therefore, it is worth putting more attention on the research of the triangular SICs.In this parper, a one-third triangular resonator with two electric walls and two virtual magnetic walls is proposed to degisn SICs. This structure is realized by taking out one-third of an equilateral or isosceles triangular resonator of substrate integrated waveguide and therefore, it is called the one-third-mode substrate integrated resonator(OTMSIR). The characteristics of the OTMSIR cavity are studied, which makes the OTMSIR a good candidate to construct wide band microwave components. Based on this and defeted ground structure(DGS) technique, a quadruple-mode bandpass filter with an OTMSIR and two bandpass filters with OTMSIRs are designed and simulated, respectively. To investigate other applications of OTMSIR, a plane compact magic-T is designed by using OTMSIRs and soltline. These components are fabricated, tested and compared to other SICs, the results indicate that the OTMSIR is an attractive candidate of microwave and millimeters-wave miniaturized components and circuits with high bandwidths.