A Low-Profile Dual-Band Multi-Port Diversity Antenna

A dual-band diversity antenna operating simultaneously at 2.45 GHz and 3.50 GHz is proposed for multipleinput multiple-output (MIMO) applications. The proposed design achieves seven modes of operations by integrating a dual-band triple-mode antenna with four additional planar dipoles, while still maintaining a low-profile configuration of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.09 \lambda_{L}$</tex> at the lowest operating frequency and an isolation of greater than 20 dB between any pair of ports. It achieves a 10 dB return loss fractional bandwidths of 4.5 % and 17.7 % at the two target bands, respectively. The proposed antenna demonstrates a significant enhancement compared to existing designs in the literature for the same application, supporting seven independent ports while achieving both pattern and polarization diversity across two targeted frequency bands.