Electrically Small Multimodal 3D Beamforming MIMO Antenna for PHY-Layer Security

TL;DR

This paper introduces a compact 3D beamforming MIMO antenna designed for physical layer security, enabling directional modulation to enhance secure wireless communication with low error rates.

Contribution

It presents a novel electrically small 3D beamforming antenna with five-mode MIMO operation and demonstrates its effectiveness for PHY-layer security via directional modulation.

Findings

Achieved low BER of 2×10^{-5} in the desired direction.

Demonstrated beamwidths of 55° azimuth and 58° elevation.

Radiation efficiency up to 55%.

Abstract

This work proposes an electrically small 3D beamforming antenna for PHYsical Layer (PHY-layer) security. The antenna comprises two layers of stacked patch structures and is a five-mode five-port MIMO system operating around 1.85 GHz with electrical size ${ka=0.98}$ and radiation efficiency of up to ${55\%}$. By studying the properties of the excited modes, phase and amplitude control allow for unidirectional beam scanning towards any direction around the elevation and azimuth planes. PHY-layer security is investigated using the directional modulation (DM) technique, which transmits unscrambled baseband constellation symbols to a pre-specified secure direction while simultaneously spatially distorting the same constellations in all other directions. Bit Error Rate (BER) calculations reveal very low values of ${2\times10^{-5}}$ for the desired direction of the legitimate receiver, with BER${<10^{-2}}$ beamwidths of ${55^{\circ}}$ and ${58^{\circ}}$ for the azimuth and elevation planes, respectively.