Coupling localized sources to controlled polarized broadside radiation using Huygens metasurfaces

We present a path for integrating arbitrary 3D localized sources with Huygens metasurfaces (HMS) to form directive broadside radiators with desirable polarization. This step is essential for development of practical devices based on this novel class of metasurfaces, harnessing both electric and magnetic sheet impedances to manipulate fields with reduced reflections. Extending previous work, we utilize the plane-wave spectral representation of the vectorial fields to synthesize passive lossless HMSs by locally enforcing power conservation and impedance equalization; polarization control is achieved via unit cell rotation. Semianalytical design formulas are derived and applied to devise an HMS coupling a vertical magnetic dipole to directive circularly-polarized radiation.