DUAL-BAND LOW PROFILE SIW CAVITY-BACKED ANTENNA BY USING BILATERAL SLOTS

In this paper, a design of a low profile cavity backed antenna consisting of bilateral slots is developed for generating two frequencies. Here, the whole antenna including substrate integrated waveguide (SIW) cavity is constructed from only one substrate with the height of 0.026λ0. The long transversal slot at the ground plane is excited by TE210 mode of the cavity and produces one hybrid mode resonance at 9.85 GHz. When the short transversal slot cut is incorporated in the top portion of the cavity, TE310 mode is perturbed, which results in generating an additional hybrid mode resonance at 14 GHz. Both these hybrid modes help to create a dual-band response. A sample of the proposed design is fabricated, and it has been verified experimentally that the bandwidths of the proposed design are 530 MHz (5.48%) and 440 MHz (3.15%) at lower and higher resonant frequencies, respectively. The antenna renders measured peak gains of 6.62 dBi and 6.44 dBi at 9.85 GHz and 14 GHz, respectively. The cross-polarization level of maximum −20 dB and same polarization planes are obtained at both the operating frequencies.