ATLAS hardware-based Endcap Muon Trigger for future upgrades

The LHC is expected to increase its center-of-mass energy from 13 TeV to 14 TeV for Run-3 scheduled from 2022 to 2024. After Run-3, upgrades for the High-Luminosity-LHC (HL-LHC) program is planned and the operation will start from 2027, increasing the instantaneous luminosity to 5.0 -- 7.5 times its nominal luminosity. Continuous upgrades of the ATLAS trigger system is planned to cope with the high event rate and keep the physics acceptance. During the Phase-1 Upgrade for Run-3, new detectors will be installed to improve the trigger performance. New trigger logic, combining information from detectors outside the magnetic field and new detectors installed inside the magnetic field, is introduced from Run-3 to reduce the trigger rate. In order to handle data from various detectors, a new trigger processor board has been developed and the design is presented. During the Phase-2 Upgrade for HL-LHC, the trigger and readout systems of the hardware-based trigger are planned to be upgraded. Full-granular information will be transferred to the trigger processor board which enables hardware-based track reconstruction to reconstruct off-line like tracks. To handle the full-granular information and perform the hardware-based track reconstruction, the trigger processor board will implement an FPGA with hundred of pairs of transceivers and huge memory resources. Expected trigger performance for the hardware-based endcap muon trigger in Run-3 and HL-LHC will also be presented.