Layer-by-layer photonic crystal horn antenna

We introduce a horn antenna in a three-dimensional layer-by-layer photonic crystal that provides highly efficient transmission from a defect waveguide to free space. This device is physically realizable, thus providing a significant advance over an ideal two-dimensional photonic crystal horn antenna. Through numerical simulations we demonstrate the directional nature of the radiation pattern in the H-plane and its broader radiation characteristics in the E-plane. The antenna is shown to achieve a bandwidth that is almost equal to that of the defect waveguide, which illustrates that this horn antenna operates as an excellent output coupler for the photonic crystal waveguide. Further, the horn antenna may be easily integrated with other layer-by-layer photonic crystal components to form ultracompact devices for communication systems.