Radiation synthesizer systems provide efficient wideband operation with an antenna, such as a loop, which is small relative to operating wavelength. Energy dissipation is substantially reduced by cycling energy back and forth between a high-Q radiator and a storage capacitance. Systems using multi-segment loop antennas match antenna input impedance to switching circuit parameters. Control signal feeds employ fiber-optic cables and reduce conductive paths. Multi-voltage DC supply configurations use parallel conductor portions of antenna loop segments and reduce the need for separate DC supply conductors. Spurious conductive loops are thereby reduced and lightweight, flexible antenna constructions are enabled.