Mode analysis of the 5 meter Terahertz antenna for Dome A, Antarctica

The terahertz windows of the 5 meter Dome A Terahertz Explorer (DATE5) are primarily over the wavelengths between 350 and 200 μm. For studying the performance of the DATE5, based on a finite element model of the whole telescope assembly, the Eigen frequencies and Eigen modes of the DATE5 structure at different elevation angles are studied. The obtained results show the ranges of first 3 Eigen frequencies are in [5.73Hz, 6.22Hz], [6.84Hz, 7.60Hz], and [10.20 Hz, 13.30Hz] respectively, and show dependence with elevation angles. All of the Eigen frequencies are larger than 5 Hz, which meet the performance requirements for this telescope.