Four-Element Meandered Sunflower MIMO Antenna for Ultra-Wideband Systems

Ultra-wideband (UWB) technology is known to have a high data rate in wireless communications due to its broad frequency range and low power consumption. Its flexibility enables a wide range of applications, including multiple-input multiple-output (MIMO) systems, suited for advanced wireless communication systems. In this manuscript a novel meandered MIMO antenna, designed explicitly for UWB applications, is proposed and studied. The antenna features meandered strips arranged in a circular pattern, resembling a sunflower. The antenna structure is built on an FR4 with 24 × 24 × 1.6 mm3 size for a single element and 48 × 48 × 1.6 mm3 for the MIMO configuration. The antenna operates over a wide frequency range between 2.9 and 20 GHz, achieving a fractional bandwidth of 151%. In the MIMO configuration, it maintains good isolation, exceeding 15 dB across the entire operating band. The measured efficiency of the antenna surpasses 75%, with a peak gain of 5.9 dBi. Additionally, key parameters for MIMO performance include an envelope correlation coefficient (ECC) below 0.002, mean effective gain (MEG) less than −3 dB, channel capacity loss (CCL) under 0.25 bps/Hz, and a total active reflection coefficient (TARC) below −20 dB.