  We propose an approach to actively tune the scattering pattern of a Mie-type
spherical antenna. The scheme is based on separate control over the induced
electric dipole and induced magnetic dipole using two coherent focused beams of
radial polarization and azimuthal polarization. By carefully tuning the
amplitude and phase relation of the two beams, a broadband unidirectional
scattering can be achieved, even at the wavelength where the antenna scatters
most efficiently. By moving the focus of one beam, a drastic switch of the
unidirectional scattering can be observed. Such scheme enables the design of
ultra-compact optical switches and directional couplers based on nanoantennas.
