An antenna system (205) includes an antenna structure (215), a receiver (220), and an antenna system controller (225). The antenna structure includes an arrangement of antennas (237), a signal combiner (240), and a switching matrix (235). The arrangement of antennas is designed to have a set of antenna element separations that are optimized to provide lowest correlation coefficients of intercepted radio signals for a corresponding set of electromagnetic environment types that vary from a very low density scattering environment to a maximum density scattering environment. The antennas (230), (231), (232), (233), (234) in the antenna arrangement each include at least one element that has a common polarization. There is at least one antenna that is a dual polarized antenna. The antenna system selects an antenna element pair that corresponds to the environment type which it is operating and thereby receives a best combined signal.