In this article, a new approach has been demonstrated for the bandwidth enlargement of a substrate integrated waveguide (SIW) cavity-backed antenna. The proposed structure employs bilateral slots, instead of unilateral slots, which is a distinct approach, in contrast to traditional cavity antennas. The proposed antenna embodies SIW cavity with a height less than 0.017λ0 and thus holds low-profile planar geometry, while retaining lower losses and light weight. The non-resonant slot, at the bottom plate, produces two-hybrid modes (odd TE210 and even TE210). The quality factor (Q) of these hybrid modes is greatly reduced by loading the resonant slot cut at the top metallic plate of the SIW cavity which leads to achieving a wideband response. A sample is fabricated and investigated at X-band. It is shown that the experimental results are well-matched with the simulated ones. The measured impedance bandwidth of the proposed antenna is 860 MHz (8.6%). Moreover, it renders a maximum gain of 6.56 dBi at 9.78 GHz and 6.75 dBi at 10.35 GHz, within the operating bandwidth. The cross-polarization radiation levels of maximum -26 dB and -28 dB are obtained at the corresponding resonant frequencies, respectively.
2. Zhou, S. G., G. L. Huang, and T. H. Chio, "A low-profile wideband cavity-backed bowtie antenna," Microw. Opt. Techno. Lett., Vol. 55, No. 6, 1422-1426, 2013.
3. Deslandes, D. and K. Wu, "Accurate modeling wave mechanisms and design considerations of substrate integrated waveguide," IEEE Trans. Microw. Theory Tech., Vol. 54, No. 6, 2516-2526, 2006.
4. Luo, G. Q., T. Y. Wang, and X. H. Zhang, "Review of low profile substrate integrated waveguide cavity backed antennas," Int. J. Antennas Propag., 746920, 2013.
5. Luo, G. Q., Z. F. Hu, L. X. Dong, and L. L. Sun, "Planar slot antenna backed by substrate integrated waveguide cavity," IEEE Antennas Wirel. Propag. Lett., Vol. 7, No. 8, 236-239, Aug. 2008.
6. Luo, G. Q., Z. F. Hu, W. J. Li, X. H. Zhang, L. L. Sun, and J. F. Zheng, "Bandwidth-enhanced low-profile cavity-backed slot antenna by using hybrid SIW cavity modes," IEEE Trans. Antennas Propag., Vol. 60, No. 4, 1698-1704, 2012.
7. Yun, S., D. Kim, and S. Nam, "Bandwidth and efficiency enhancement of cavity-backed slot antenna using a substrate removal," IEEE Antennas Wirel. Propag. Lett., Vol. 11, 1458-1461, 2012.
8. Yun, S., D. Kim, and S. Nam, "Bandwidth enhancement of cavity-backed slot antenna using a via-hole above the slot," IEEE Antennas Wirel. Propag. Lett., Vol. 11, 1092-1095, 2012.
9. Yang, W. and J. Zhou, "Wideband low-profile substrate integrated waveguide cavity-backed E-shaped patch antenna," IEEE Antennas Wirel. Propag. Lett., Vol. 12, 143-146, 2013.
10. Mukherjee, S., A. Biswas, and K. V. Srivastava, "Bandwidth enhancement of substrate integrated waveguide cavity backed slot antenna by offset feeding technique," IEEE Applied Electromagnetics Conf. (AEMC), Dec. 2013.
11. Baghernia, E. and M. H. Neshati, "Development of a broadband substrate integrated waveguide cavity backed slot antenna using perturbation technique," Appl. Comput. Electro. Soc. J., Vol. 29, No. 11, 847-855, 2014.
12. Heydarzadeh, F. and M. H. Neshati, "Design and development a wideband SIW based cavity-backed slot antenna using two symmetrical circular corner perturbations," Int. J. RF Microw. Comput. Aided Eng., Vol. 28, No. 9, e21552, 2018.
13. Chaturvedi, D., "SIW cavity-backed 24o inclined-slots antenna for ISM band application," Int. J. RF Microw. Comput. Aided Eng., Vol. 30, No. 5, e22160, 2020.
14. Ali, H. A., E. Massoni, L. Silvestri, M. Bozzi, L. Perregrini, and A. Gharsallah, "Increasing the bandwidth of cavity-backed SIW antennas by using stacked cavities," Int. J. Microw. and Wireless Tech., Vol. 10, No. 8, 942-947, 2018.
15. Lokeshwar, B., D. Venkatasekhar, and A. Sudhakar, "Dual-band low profile SIW cavity-backed antenna by using bilateral slots," Progress In Electromagnetics Research C, Vol. 100, 263-273, 2020.