A design of a half-mode substrate integrated waveguide (HMSIW) cavity-backed self-diplexing antenna is proposed with a two-layer structure. The top layer comprises two HMSIW based cavities, and radiating patches are etched on the top-cladding of each cavity. The radiating patches are excited by two distinct printed microstrip lines on the backside of the bottom layer by using shorting-pins. The shorting-pin excites the corresponding cavity in its dominant mode, which resonates at two different frequencies in X-band. The simulated results demonstrate that the proposed design resonates at 8.20 GHz and 10.55 GHz with an isolation of higher than -25 dB between two excitations, which helps to introduce the self-diplexing phenomenon. Also, both resonant frequencies can be tuned independently by varying the dimensions of the corresponding cavity. Moreover, HMSIW cavity-backed structure and proposed feeding technique reduce the overall size of the antenna significantly, while it maintains high gain and unidirectional radiation characteristics for both operating frequencies.
2. Chaturvedi, D. and S. Raghavan, "Compact QMSIW based antennas for WLAN/Wban applications," Progress In Electromagnetics Research, Vol. 82, 145-153, 2018.
3. Kumar, A. and S. Raghavan, "Wideband slotted substrate integrated waveguide cavity-backed antenna for Ku–band application," Microw. Opt. Technol. Lett., Vol. 59, 1613-1619, 2017.
4. Luo, G. Q., Z. F. Hu, Y. Liang, L. Y. Yu, and L. L. Sun, "Development of low profile cavity backed crossed slot antenna for planar integration," IEEE Trans. Antennas Propag., Vol. 57, 2972-2979, 2009.
5. Zhang, T., W. Hong, , Y. Zhang, and K. Wu, "Design and analysis of SIW cavity backed dual-band antennas with a dual-mode triangular-ring slot," IEEE Tran. Antennas Propag., Vol. 62, 5007-5016, 2014.
6. Kumar, A. and S. Raghavan, "A self-triplexing SIW cavity-backed slot antenna," IEEE Antennas and Wireless Propagation Letters, 2018, DOI:10.1109/LAWP.2018.2815665.
7. Sam, S. and S. Lim, "Electrically small complementary split-ring resonator antenna on eighth-mode substrate integrated waveguide," Electron Lett., Vol. 49, 519-521, 2013.
8. Kumar, A. and S. Raghavan, "Broadband dual-circularly polarised SIW cavity antenna using a stacked structure," IET Electronics Letters, Vol. 53, No. 17, 1171-1172, 2017.