A Compact Substrate Integrated Waveguide Cavity-Backed Self-Triplexing Antenna

A low-profile and efficient substrate integrated waveguide (SIW) based self-triplexing antenna for Worldwide Interoperability for Microwave Access (WiMAX), fifth-generation (5G) and wireless LAN (WLAN) applications is proposed in this brief. The antenna consists of two SIW cavities, out of which one is embedded in the other. The outer SIW cavity is excited with 50Ω microstrip lines while the inner cavity inside the outer one is excited through a 50Ω coaxial probe. The proposed triplexingantenna works at three different frequencies [3.5 GHz (WiMAX band), 4.8 GHz (5G band) and 5.4 GHz (WLAN band)]. The outer SIW cavity provides two resonances at 4.8 and 5.4 GHz, while the inner cavity generates resonance at 3.5 GHz. High isolation (>26 dB) between the three ports is observed upon excitation of one cavity mode (TE
₁₀₁
) and one patch mode (TM
₁₀
). The antenna posses high gain and efficiency for all three bands along with >16.1 dB front-to-back ratio (FTBR). The proposed model is fabricated for validation of the simulated results. A reasonable matching between the simulated and measured results is observed.