4-Port MIMO Antenna with Defected Ground Structure for 5G Millimeter Wave Applications

TLDR

The authors propose a 4‑port MIMO antenna array for 5G millimeter‑wave applications. The array consists of two identical rectangular slotted‑patch elements fed by a T‑junction power combiner, uses a defected ground with rectangular, circular, and zigzag slots, incorporates polarization diversity for high isolation, and was fabricated and measured. Measurements confirm operation over 25.5–29.6 GHz with a peak gain of 8.3 dBi, low envelope correlation, and favorable channel‑capacity, effective‑gain, and diversity‑gain metrics, indicating suitability for 5G MIMO.

Abstract

We present a 4-port Multiple-Input-Multiple-Output (MIMO) antenna array operating in the mm-wave band for 5G applications. An identical two-element array excited by the feed network based on a T-junction power combiner/divider is introduced in the reported paper. The array elements are rectangular-shaped slotted patch antennas, while the ground plane is made defected with rectangular, circular, and a zigzag-shaped slotted structure to enhance the radiation characteristics of the antenna. To validate the performance, the MIMO structure is fabricated and measured. The simulated and measured results are in good coherence. The proposed structure can operate in a 25.5–29.6 GHz frequency band supporting the impending mm-wave 5G applications. Moreover, the peak gain attained for the operating frequency band is 8.3 dBi. Additionally, to obtain high isolation between antenna elements, the polarization diversity is employed between the adjacent radiators, resulting in a low Envelope Correlation Coefficient (ECC). Other MIMO performance metrics such as the Channel Capacity Loss (CCL), Mean Effective Gain (MEG), and Diversity gain (DG) of the proposed structure are analyzed, and the results indicate the suitability of the design as a potential contender for imminent mm-wave 5G MIMO applications.