Energy Efficient Dynamic Directional Modulation with Electrically Small Antennas

This letter proposes a compact and energy-efficient directional modulation scheme for small power constrained devices (e.g., Internet of Things wireless sensors). The uses uniform circular array monopole antennas, with single radiofrequency chain antenna active at time. antennas can be located in close proximity, offering significant size reduction. Furthermore, the was demonstrated to operate successfully an 0.6 λ diameter. system does not generate additional artificial noise, limiting interference other systems. Finally, switching sequence randomly generated without fine-tuned synchronization transmitter.