A terminal active radar homing seeker operating at X-band is installed in the nose. The 23kg high explosive warhead designed by Chamberlain is fitted with a smart RF proximity fuse.
In June 2007, Raytheon announced the development of additional capabilities for SL-AMRAAM: the SL-AMRAAM ER missile, which will have a range of about 40km, and the capacity to launch Raytheon AIM-9X Sidewinder missiles, which have a range of 10km.
Raytheon AN/MPQ-64 Sentinel radar to carry out the surveillance and target search, acquisition, identification and tracking functions. The electronically scanned phased array radar uses range gate pulse doppler operation at X-band. Sentinel uses a high scan rate of 30rpm. The range is 75km.