Four-port low-profile broadband antenna with fan-leaf slits and shorting pins for 5G mobile applications

Abstract

A four-port low-profile broadband patch antenna is designed for fifth-generation (5G) multi-input multi-output (MIMO) mobile applications. The designed antenna loads shorting pins S1 and S2 on a square patch with etched fan-leaf slits, making the parasitic patch work more visible. In addition, loading shorting pin S3 excites a low-frequency resonant mode, which enables the antenna to completely cover frequency ranges of 3.3–5 GHz (5G N77 and N79 bands). The effective height of the designed antenna is only 3.7 mm (0.05λ at 4.15 GHz). The antenna achieves a good balance between impedance bandwidth and profile, realizing wide bandwidth coverage. To confirm the precision of the results, the designed antenna is fabricated and measured. The measured results show that the −6 dB impedance bandwidth covers 3.3–5 GHz. All the isolation between ports are superior to 12 dB. The envelope correlation coefficients (ECCs) is below 0.15 and the overall efficiency is between 50% and 90% in the 3.3–5 GHz.