| abstract |
The present invention relates to a Cassegrain radar antenna. The antenna comprises a feed and a metamaterial panel. The metamaterial panel comprises multiple core layers having identical refractive index distributions. Each core layer of the metamaterial panel consists of multiple metamaterial units. The metamaterial units comprise unit substrates having artificial metal microstructures or artificial pore structures. By changing the pattern of refractive index distribution within the metamaterial panel, the Cassegrain radar antenna of the present invention allows for greatly improved far-field power of the antenna, thus extending antenna transmission distance, while at the same time, by arranging a wave-absorbing material layer within a cavity of the antenna, allows for improved front-to-back ratio of the antenna, thus increasing antenna directionality. |