摘要 |
<p>The performance of a microwave antenna is improved by incorporating a fine wire dielectric material (16) which has a dielectric constant ε of less than unity at microwave frequencies. The effect of the dielectric material (16) is to refract microwaves (20) so that the antenna (14) appears to have a larger aperture than that of its physical size. Furthermore, by selecting the transmission cut off frequency of the dielectric material, two antenna elements which are intended to operate within different frequency bands can be mounted one behind the other.</p> |