Unmanned Systems Technology 038 l Skyeton Raybird-3 l Data storage l Sea-Kit X-Class USV l USVs insight l Spectronik PEM fuel cells l Blue White Robotics UVIO l Antennas l AUVSI Xponential Virtual 2021 report

to correct for ionospheric disturbances to output corrections that are broadcast to subscribers’ antennas tuned to receive transmissions over the L band or a cellular band. Electronic steering As mentioned, beam steering can be highly useful for maintaining polarisation between an unmanned vehicle and its GCS. Traditionally, this has been performed mechanically, such as through a gimballed directional antenna, which works well enough if the gimbal does not have to change direction frequently or rapidly. However, if the vehicle is moving at speed around the GCS and needs to circle closely around it, gimballed directional antennas rarely move fast enough to maintain an accurate link. Also, as with any machinery, the moving parts on the gimbal are subject to mechanical failure and could significantly disrupt operations if they break. Electronically steered antennas have numerous advantages over mechanical steering, however, and eliminate key drawbacks. They can vary in design, but one of the most effective architectures available now is a digital array, consisting of several panels of miniature directional patch antennas. These are controlled through digital signal processors (DSPs) to enable dynamic configuration of every element of the multi-element array. The panels are oriented so that transceivers point in virtually every direction around the array, accounting for all altitudes and positions within line of sight. Modern processor speeds enable these arrays to detect sudden changes in terms of where incoming data is arriving from, and hence switch and turn the direction of their transmissions and receptions within microseconds. Not only are the comparatively slow turning speeds of gimballed antennas overcome in this way, enabling consistent links with agile and even supersonic UAVs, but a singular electronic beamforming array could also be used to monitor or even command a swarm of vehicles around it, without losing telemetry or control. By contrast, a gimballed antenna can point in only one direction at a time. Using DSPs in such arrays allows them to be interfaced via Ethernet, which is key to enabling each unmanned vehicle to be instantly recognised through its IP address over long ranges and at broadband speeds. This effectively creates an ad hoc IP-based network between the radios and antennas of a GCS and an unmanned fleet, with easy integration of – and interoperability between – other IP-based systems. Developing these electronically steered arrays is not easy though. In hardware terms, power consumption and the complexity of the overall system architecture can spiral out of control Air | Ground | Sea | Ground Control Stations Made in San Diego high-performance Antennas for unmanned systems Southwest Antennas engineers rugged antennas and RF accessory solutions that enable unmanned system communication for military, law enforcement, and commercial customers around the world. Contact us to learn how we can keep you connected when it matters most. southwestantennas.com/unmanned Omni & directional antennas Embedded antennas MIMO antennas RF filters & signal processing accessories