This paper presents an eight‐element antenna array designed for triple‐band multi‐input multi‐output (MIMO) operation in fifth‐generation (5G) mobile terminals. Each antenna element comprises a triple open‐loop structure on a metal frame and fed by a customized feed element. The triple open‐loop design not only significantly miniaturizes the radiator but also provides wide bandwidth. The dimensions of the proposed antenna array are approximately 8.2 × 7 mm, with a small ground clearance of 8.2 × 0.3 mm. It fully covers 5G New Radio (NR) bands N41 (2.496–2.690 GHz), N77 (3.3–4.2 GHz), and N79 (4.4–5.0 GHz) at the three resonance frequencies. Several critical parameters—including bandwidth, reflection coefficient, isolation, total radiation efficiency, and envelope correlation coefficient—have been studied. An antenna prototype was fabricated and measured; excellent agreement between simulation and experiment confirms that the triple open‐loop array is well suited for 5G handsets demanding compact, triple‐band MIMO antennas.
Huang et al. (Thu,) studied this question.