We study the response of the magnetopause to incident magnetosheath ULF fluctuations by combining the linear magnetohydrodynamics (MHD) approach with harmonic analysis. We consider plane wave fronts arriving at the magnetopause with various tangential wavelengths. The fluctuations in the magnetosheath are pulse trains or waves with a broadband ULF spectrum. We obtain the magnetopause response to these fluctuations based on the computation of the transmission, reflection, and absorption characteristics of monochromatic linear MHD waves at different frequencies in a given equilibrium magnetopause configuration. Particular attention is given to MHD wave mode conversion as an ingredient for explaining the enhanced electromagnetic fluctuation level near the magnetopause.