Compact Stacked-Patch Antenna for Directional Modulation in Azimuth and Elevation Planes

This work proposes a compact stacked-patch antenna capable of beamsteering in the vertical and horizontal directions. These characteristics are studied to realize directional modulation (DM) schemes in the vertical and horizontal planes, using a structure of 0.56λ diameter. The design offers a unidirectional beamsteering across the entire xy-plane, with a scanning range of 118° and 112° in the xz and yz-planes, respectively. A peak realized gain of 6.75 dBi is achieved, with an isolation better than 15 dB at the center frequency of 2.4 GHz. The directional modulation performance shows a beamwidth with Bit Error Rate (BER) < 10
⁻²
of 33° in the horizontal plane, and 50° for the elevation planes. This performance is proposed to improve the secrecy and privacy of data transmission in the growing field of small Internet of Things (IoT) technology.