Other quasi-optical components

Rectenna arrays have been developed for arbitrarily polarized broadband radiation (Joe Hagerty) with reasonable efficiencies (50%) for low incident power densities. The applications are energy recycling. A variety of loaded grids for mode selection, tuning, switching, phase modulation, polarization-conversion etc. have also been demonstrated (see publications).

Spiral antenna array (left and right-hand circularly polarized) integrated with diodes for reception and rectification of radiation in the 1-12GHz range (Joseph Hagerty)