Dual-band Cavity-Backed Dumbbell-Shaped Slot Antenna

In this paper, a novel dumbbell-shaped slot along with thin substrate integrated waveguide (SIW) cavity backing is used to design dual-band slot antenna. The design in this paper has unidirectional radiation pattern, high gain, high (FTBR) at each resonant frequency while having low profile, planar configuration. The unique slot shape creates complex current distribution at different frequencies that results in simultaneous excitation of hybrid mode at higher frequency along with conventional mode in the cavity. Both conventional mode and the hybrid mode helps the modified slot to radiate at the corresponding resonant frequencies resulting in compact, dual-band antenna. This designed antenna resonates at 7.1 GHz and 11.5 GHz with gain of 6.7 dB and 5.8 dB respectively. The FTBR of the antenna are above 10 dB at both operating frequencies.