What is the TRML-4D? HENSOLDT’s GaN AESA Air Defense Radar
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When a Shahed drone appears on a radar screen over Kyiv, the detection chain often begins with a German sensor. HENSOLDT’s TRML-4D — a C-band GaN AESA radar capable of simultaneously tracking over 1,500 targets at ranges up to 250 km — has become one of the most consequential air defense sensors of the current conflict in Ukraine. Introduced at Eurosatory 2018, it was purpose-built for exactly the kind of threat environment Ukraine now faces: mass drone attacks, cruise missile salvos, and supersonic missiles operating across a cluttered, contested airspace.
The TRML-4D’s combination of GaN transmit-receive modules with multiple digitally formed beams gives it two critical operational characteristics. First, simultaneous surveillance and fire control from a single aperture — eliminating the need for separate search and track radars. Second, a 0.01 m² minimum RCS detection threshold that encompasses small commercial UAVs, loitering munitions, and low-observable cruise missiles that older systems miss.
In Ukraine, these characteristics have translated directly into operational value. The Bundeswehr-funded TRML-4D transfers since 2022 have contributed to detection and engagement of Russian cruise missiles and Shahed-series UAS that previously evaded less capable radars.
