Image plate/short backfire antenna

摘要

The described embodiments of the present invention provide a high-gain antenna while allowing for the inclusion of devices within the antenna array. In one embodiment of the invention an array of receiver/transmitter elements is positioned in a pan-like reflector base. The elements are positioned one-quarter of a wavelength from the surface of the base. The wavelength is the wavelength of the chosen frequency of transmission or reception of the antenna. A partially reflective plate is positioned one-half wavelength from the base and thus one quarter wavelength from the elements. Reflective disks are also positioned one-half wavelength above the base and are positioned directly above the elements. The disks create a resonant cavity around the elements for waves of the chosen frequency arriving from near normal to the plane of the base or being emanated from the elements at a normal or near-normal angle. The partially reflective plate extends this resonant area spatially from the element. Because of the extending effect, wider dispersion between array elements may be utilized, wider dispersion between array elements may be utilized while maintaining good gain and side-lobe characteristics. In another embodiment the wider spatial characteristics allow the use of an irregular array. This array allows space for electro-optical devices in the array itself. Another embodiment includes an optically transparent portion of the base. This transparent portion is treated so the surface of it is conductive and thus electromagnetically reflective. The transparent portion allows for optical transmission to sensors located beneath the transparent portion.