We introduce a new dipolar recoupling scheme, dubbed PARIS-xy (phase-alternated recoupling irradiation scheme using orthogonal radio-frequency phases), to promote efficient broadband magnetization exchange between C-13 nuclei using moderate radio-frequency amplitudes at very high magnetic field strengths and spinning speeds. Experimental observations for a wide range of spinning frequencies 30 <= nu(rot) <= 60 kHz and magnetic field strengths (B-0 = 9.4, 17.6 and 21.2 T) are backed up by numerical simulations. (C) 2010 Elsevier B. V. All rights reserved.