Grey-scale holographic structure and system for generating a millimeter-wave collimated wavefront in a compact range

摘要

Embodiments of a grey-scale holographic structure and system for generating a collimated wavefront in a compact range are generally described herein. In some embodiments, the grey-scale holographic structure comprising millimeter-wave transmissive material having a surface arranged to provide differing amounts of phase-delay to an incident millimeter-wave wavefront as the incident wavefront passes through the material. The grey-scale holographic structure may comprises a plurality of layers (N) to provide a phase total delay of lambda which results from a series tuned layers, each having a thickness of a wavelength/N. Each layer provides a predetermined amount of phase delay allowing the structure to operate as a phase-delay hologram.

主权项

1. A method of designing and fabricating a grey-scale holographic structure comprising:
generating a diffractive-optics model to convert an incident millimeter-wave wavefront based on amplitude and phase characteristics to an output wavefront having predetermined characteristics, the diffractive-optics model comprising one or more computer generated holograms (CGHs) and indicating an amount of phase delay at each location across a surface of the CGH; generating a bitmap from the diffractive-optics model, the bitmap comprising a plurality of values, each value representing an amount of phase delay that is associated with a layer height; and fabricating the grey-scale holographic structure from millimeter-wave transmissive material based on the bitmap using a three-dimensional fabrication process, the holographic structure comprising a plurality of layers having layer heights based on values of the bitmap.