| 摘要 |
<p>Substantially planar phase shifting elements, for example for use in antennas, may be constructed to deviate electromagnetic radiation in the frequency range 30 MHz-300 GHz. Phase shifting elements analogous to lenses, prisms and focussing reflectors impart a phase shift to radiation incident thereon which varies with the position of incidence. Multi-layer phase shifting elements comprise spaced thin dielectric sheets with a graded metallic coating providing a suspectance varying with position on the sheet. Antenna apparatus uses the phase shifting elements analogous to lenses and focussing reflectors as the antenna itself, and uses the phase shifting elements analogous to prisms for beam steering.</p> |
