Design of compact dual-band substrate integrated waveguide filtenna

A compact dual-band substrate integrated waveguide (SIW) filtenna is presented. A dual-mode SIW cavity, resonating at its fundamental mode TE110 and high-order mode TE120, which respectively dominate the lower and upper passbands, is employed as the feeding cavity. After that, a slot-loaded SIW cavity, performing as two half-mode radiating cavities, is perpendicularly arranged over the feeding cavity for the purpose of expanding the operational bandwidth and also strengthening the filtering response. Furthermore, two metal posts are utilized to independently regulate the coupling strength of magnetoelectric energy of the two passbands, respectively. A prototype of this dual-band SIW filtenna is designed, fabricated, and tested for validation. The measured results agree well with the simulated values, demonstrating that the maximum realized gains are 4.9 and 5.38 dBi, and the impedance bandwidths are 2.1% (2.792-2.852 GHz) and 4.1% (3.992-4.16 GHz) for lower and upper passbands, respectively.