Compact EMSIW Quadruplexing Antenna

Abstract

This letter proposes a compact self-quadruplexing antenna based on an eighth-mode substrate integrated waveguide (EMSIW). The proposed antenna design integrates the unique properties of the EMSIW to achieve an efficient and isolated quadruplexing functionality with a highly compacted geometry. The proposed design operates at different frequencies: 4.3 GHz for Port-1, 5.2 GHz for Port-2, 5.8 GHz for Port-3, and 6.9 GHz for Port-4 when each respective port is active. A full-mode square SIW configuration is considered, which is subsequently transformed into an uneven eighth-mode SIW. Different dimensions of slots are strategically added to each cavity to achieve different operating frequencies and compactness. As a result, it takes up a compact area measuring 0.11$\lambda _{g}^{2}$. In addition, the proposed design ensures reasonable separation between the resonators to maintain isolation level of 29.1 dB. The proposed antenna gains are observed as 5.19 dBi (4.3 GHz), 5.63 dBi (5.2 GHz), 6.88 dBi (5.8 GHz), and 7.57 dBi (6.9 GHz).The proposed quadruplexing antenna offers attractive features that make it well suited for next-generation wireless communication devices. These features include mainly compact size, excellent isolation, independently controllable frequency bands, and high gain characteristics, making it highly desirable for modern wireless communication.