Design of self-diplexing and quadruplexing Substrate Integrated Waveguide (SIW) antennas for C- and X-band high-speed wireless applications

Abstract

Compact antenna designs have become a critical component in the recent advancements of wireless communication technologies over the past few decades. This paper presents a self-multiplexing antenna based on diplexing and quadruplexing Substrate-Integrated Waveguide (SIW) cavities. The diplexing structure incorporates two V-shaped slots, while the quadruplexing structure advances this concept by combining the slots to form a cross-shaped configuration within the cavity. The widths and lengths of the slots are carefully tuned to achieve variations in the respective operating frequencies without affecting the others. The proposed diplexing antenna resonates at 8.48 and 9.2 GHz, with a frequency ratio of 1.08, while the quadruplexing antenna operates at 6.9, 7.1, 7.48, and 8.2 GHz. Both designs exhibit isolation levels well below -20 dB and achieve a simulated peak gain of 5.6 dBi at the highest frequency, with a compact cavity area of 0.56 λg². The proposed antennas operate within the NR bands (n12, n18, n26), making them suitable for modern high-speed wireless communication systems. Moreover, the properties like multiband operation, compactness, high isolation, low loss, and low interference make the antenna favorable for the high-speed railway communication systems.

Keywords

Substrate Integrated Waveguide (SIW) / Multiplexing antenna / High-speed isolation / Gain / Multiple frequencies / Frequency ratio

CRediT authorship contribution statement

Ashish Kumar: Resources, Formal analysis, Conceptualization. Ahmed J.A. Al-Gburi: Writing - review & editing, Validation, Supervision, Project administration. Bhim Sain Singla: Writing - original draft, Software, Methodology.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

The authors would like to thank Punjabi University, Chitkara University in India, Universiti Teknikal Malaysia Melaka (UTeM), and the Ministry of Higher Education (MOHE) of Malaysia for supporting this project.

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