This paper describes a long-term project exploring advanced visual interfaces for antenna design. MERL developed three successive prototypes that embodied an evolution towards larger scales and more concrete semantics for visualization of large sets of candidate designs and then winnowing them down. We experimented with multidimensional scaling and then collective line graphs before settling on linked scatterplots to visualize performance in a design of up to 10 million antennas at a time. In the end, the scatterplot solution was most successful at balancing intelligibility with visualization of the space as a whole. The design allows for adding more 1D or 2D linked feature visualizations if needed, and it smoothly transitions to other