Quadruplex Slot Antenna for Dual-standard Operation with Small Frequency Ratio

In this communication, a novel four-port slot antenna designed for both 5G New Radio (NR) and WiFi operations is introduced. Wideband NR antennas are achieved using a hybrid mode concept. Then, two NR slot antennas are co-designed as a radiative bandstop structure. By moving the resonance frequencies of the hybrid modes close to the band-reject points of this bandstop filter, a wideband decoupled dual-antenna structure is achieved. To enhance functionality, two additional ports are incorporated into the dummy slot area between these two NR ports, resulting in a quadruplex antenna. In this final configuration, two of the antennas are optimized for 5G NR applications, covering the 5G N77, N78, and N79 bands (3.3 GHz-5.0 GHz), while the remaining two antennas serve the WiFi band (5.15 GHz-5.8 GHz). Compared to other presented works, the simulation and experimental results demonstrate that this work not only, for the first time, achieves simultaneously wideband in-band and small frequency ratio (1.05) out-of-band duplex in one single module, but also has the advantages of high isolation, compact size, and low cost.