Yagi–Uda antenna or Yagi Yutian Antenna is a directional antenna consisting of a dipole and additional parasitic elements (such as a reflector and at least one deflector). It is an ideal choice for medium range RF communication between two points and can be used for anti drone operations. In fact, many of the first anti drone "guns" looked similar to these improvised devices.
The description of the YouTube video provides more information. The unnamed man in the video is apparently a member of the 100th Brigade of the militia of the Donetsk People's Republic, which claims to be in the separatist region of Ukraine. Although YouTube Machine translation from Russian to English is intermittent, it can be concluded that the anti unmanned machine gun is the result of the combination of "spare parts" and is the only existing one. War Gonzo insists that the specific details of the exact use of spare parts and any further information about gun development are "military secrets".
At the short moment when it appeared on the screen, the gun itself seemed to be a "bucket" consisting of an ambiguous boxy case and butt, a trigger that might be hung on the tactical belt, and a tape that seemed to be composed of two Yagi–Uda antenna connected together by electronic devices. If this DIY anti drone gun is truly effective, it will be those antennas that provide radio frequency interference capability, which will pose a threat to Ukrainian drones.
Nowadays, they have higher production quality in terms of configuration and ergonomics. Taking the Dronegun Tactical for anti drone system design as an example.
Dronegun Tactical uses Yagi–Uda antenna technology to obtain the jamming frequency range needed to defeat the intended target. When a drone is attacked and interfered by Dronegun's multi band radio frequency interference, the Drone Shield website explains that in at least most cases, the drone will "respond by landing vertically or returning to its remote control or starting point". Basically, the system will interfere with the remote control command link and place the drone in the default autonomous recovery or landing mode. If the Ukrainian drone in the video is attacked by similar interference technology, it can explain why it appears to have suffered minimal damage because its landing is controlled.
The precarious but sometimes ingenious improvisation combat technology has become a component of the conflict between Russia and Ukraine, and many components of these systems can be purchased on the market and online. Due to this accessibility, consumer grade drones have spread throughout the airspace above conflict zones, including Ukraine's airspace, so the emergence of temporary anti drone systems seems to be a logical response to the threat.
The so-called Ukrainian quadcopter drone in the video appears to be a Chinese made DJI Mavic 2, a commercial model known for use in conflicts that can be easily purchased online from websites such as Amazon, or at least with very similar designs Therefore, although the appearance may not be satisfactory, the casually developed simple anti unmanned machine gun may achieve success, but there are still serious issues with the legality of this gun.
This is not to say that we have not yet seen non-state actors using commercial signal jammers. For example, the new generation cartel in Jalisco, Mexico, a drug trafficking group known for its Spanish acronym CJNG, shared a video in June 2021 showing some members of its "elite group" equipped with cellular jammers, highlighting the increasing spread of commercial signal interference parallel to the technology of simple drones themselves. Considering that the separatist forces supported by Russia appear poorly equipped, simple anti drone weapons may be their only choice to counter the threat of low-end reconnaissance drones or drones equipped with explosive ordnance.
