[en] The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton–proton collisions produced at the Large Hadron Collider (LHC) at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 10"3"4 cm"−"2 s"−"1. The High Luminosity LHC (HL-LHC) programme is now developed for up to 5–7 times the design luminosity, with the goal of accumulating an integrated luminosity of 3000 fb"−"1. In the HL-LHC phase, the increased radiation levels and an improved ATLAS trigger system require a replacement of the Front-end (FE) and Back-end (BE) electronics of the LAr Calorimeters. Results from research and development of individual components and their radiation qualification as well as the overall system design will be presented.