The ATH1G18A is a microwave horn antenna that operates from 1 to 18 GHz. It provides an isotropic gain of more than 7 dB and can handle an input power of up to 300 watts. This antenna provides constant high intensity fields necessary for RFI/EMI field testing within and beyond the confines of a shielded room and is designed to perform emissions measurements when calibrated. The antenna measuring 24.1 x 15.2 x 22.9 cm has an N-type female connector and can be easily mounted on a tripod. The ATH1G18A can be custom calibrated to a user’s requirements.