Normalized radiometer bandpass profiles for LFI 30 GHz (top left), 44 GHz (bottom left), and 70 GHz (right) with a resolution of 100 MHz. Within each feed horn are two orthogonal linearly polarized components, denoted “M” and “S” for main- and side-arm radiometers, for measuring Q and U polarization. Individual bandpasses are highlighted in bold and the remaining are plotted behind for ease of comparison.