A Wideband Triple-mode Substrate Integrated Waveguide Cavity-backed Slot Antenna

In this paper, A wideband substrate integrated waveguide (SIW) cavity-backed slot antenna with triple resonances is presented. The SIW cavity used for the antenna is fed by an offset coaxial probe to excite the TE210 and TE410 modes, and two radiation slots are etched on the left and right sides of the cavity. The TE410 mode is split into two resonances by the perturbation of the two slots. Besides, several pairs of shorting vias are loaded inside the cavity for moving up the TE210 mode so as to merge it with the two split TE410 modes. At the center of the cavity, a shorter slot and two shorting vias are introduced for the impedance matching. Thus, these three modes can be allocated together to achieve a wideband characteristic. Simulated results show that the proposed antenna has a bandwidth of 20.2% (from 4.7 GHz to 5.75 GHz) and a peak gain of 9.88 dBi, while keeping a low profile of 0.038.0 (wavelength in free space).