Independent control of harmonic amplitudes and phases (adapted from [31]). (a) Conceptual illustration. (b) Schematic of the coding element featuring four varactor diodes. (c) Measured amplitudes and phases at various harmonic orders, for different combinations of the biasing voltages. (d) Measured scattering patterns at the harmonic order +1, for three different spatial codings; patterns of different colors illustrate the possibility to independently control the amplitude by acting on the temporal coding. (e) Representative examples of multi-order harmonic tailoring of the scattering patterns (measured and theoretical).