Self-Diplexing Antenna based on QMSIW with High Isolation for 5G NR Band Applications

In this paper, a self-diplexing antenna based on a quarter-mode substrate integrated waveguide (QMSIW) is presented. The diplexing function is accomplished by incorporating an cross-shaped slot on the top metallic plane of QMSIW. The antenna operates at resonant frequencies of 4.44 GHz and 5.24 GHz and achieved the corresponding port isolation of 39 dB and 46 dB, respectively. The self-diplexing microfluidic sensor exhibits high gain of 6.08 dBi and 5.87 dBi at the corresponding operating frequencies by the utilization on thinner substrate with compact antenna electrical size of 0.17 $\lambda _0^2$ (λ0 is the free space wavelength at the lowest resonant frequency). The 4.44 GHz frequency corresponds 5G NR band n79, which is crucial for enhanced mobile broadband (eMBB) applications. Meanwhile, the 5.24 GHz corresponds 5G NR band n46, is well-suited for private industrial 5G networks.