Ultra-pure digital sideband separation at sub-millimeter wavelengths R. Finger, F. P. Mena, A. Baryshev, A. Khudchenko, R. Rodriguez, E. Huaracan, A. Alvear, J. Barkhof, R. Hesper and L. Bronfman A&A, 584 (2015) A3 Published online: 13 November 2015 DOI: 10.1051/0004-6361/201526503