A system and method for arbitrarily switching phase and amplitude at an antenna. A Direct Spatial Antenna Modulation (DSAM) system makes use of the spatial characteristics of a radiating antenna structure to directly alter a signal transmitted or received by the radiating structure. A data stream maps a carrier to different spatial points of excitation in the antenna structure, where each chosen configuration has different radiating characteristics including phase, amplitude, and polarization, which can be used represent data symbols. The spatial points of a radiating structure may be mapped directly to In-Phase and Quadrature components of the output using two spatial feedpoints and amplitude control to the feedpoints. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this Abstract.