This article presents a novel dual-fed triple-frequency bands antenna using quarter-mode (QM)/ Eight-mode (EM) substrate integrated waveguide (SIW) cavity resonators. A V-shaped slot is etched into the patch to divide the half-mode cavity into one QM and two EM cavities. One section of the EM cavity and QM cavity are excited with the help of individual micro-strip feedlines. This configuration yields two distinct frequency bands at 4.85 GHz due to TE110 mode of the EMSIW cavity and 5.87 GHz due to TE110 mode of the QMSIW cavity confirming the self-diplexing property. Later, when both the EM cavity sections are joined with the help of two metallic strips, an additional resonance appears at 7.34 GHz due to the excitation of TE120 mode. As compared to the conventional counterparts, the proposed structure is compact and simple. The footprint of the top patch is 0.6λ1 × 0.3λ1. To authenticate the proposed idea, the design is experimentally verified, and the measured results show a good covenant with the simulated results.
