2026-05-26 Latest Published
By Xiaoyan Wei
Zhonggen Wang
Wenyan Nie
Chenlu Li
Zhengting Zhang
Progress In Electromagnetics Research C, Vol. 171, 1-13, 2026
Abstract
This paper proposes a flexible four-element super-wideband (SWB) multiple-input multiple-output (MIMO) antenna based on characteristic mode analysis (CMA) for wearable wireless communication, broadband sensing, and wireless body area network (WBAN) applications. The antenna employs a spiral mesh radiator combined with a defected ground plane incorporating triangular and T-shaped slots to form a multi-slot-coupled current path, enabling the cooperative excitation of multiple characteristic modes. The proposed antenna achieves an impedance bandwidth of 3.23-44.68 GHz, satisfying the SWB criterion. A four-port MIMO configuration is adopted to enhance diversity and isolation performance. Measured results agree well with simulations, with port isolation better than 20 dB across the operating band. In addition, the envelope correlation coefficient (ECC) is below 0.0015; the diversity gain (DG) is close to 10 dB; the total active reflection coefficient (TARC) is below -10 dB; and the channel capacity loss (CCL) is less than 0.12 bit/s/Hz. The antenna also maintains stable SWB impedance matching and radiation performance under bending conditions, making it suitable for flexible SWB wearable and WBAN systems.
