Antenna system design for multicopter UAVs utilizing characteristic modes

Multicopter UAVs have limited real estate for the antennas and the driving electronics. Often times, antennas are placed either too close to the electronics, or in the landing gear of the drones. From an EMC point of view, these are highly undesirable locations that typically result in significant radiated desense which impacts the system overall performance. Here, we use characteristic modes for better understanding of the source of desense, and we use the resulting insight as a guide for alternate antenna placement. Next, a conformal helical antenna system operating at 2.4–2.5 GHz frequency band is designed for multicopter UAV applications. Specifically, six helical antennas are placed onto the six arms of a hexacopter UAV to construct an antenna system for UAV-to-ground station and/or UAV-to-UAV communications. In addition to minimizing de-sense, the beam of the antenna system can be controlled by adjusting the amplitude and phase combinations of the excitations of the six helical antenna elements, which helps to address other interferences such as those generated by intentional jammers.