US Patent 7688268 Multi-band antenna system

The present invention is an improved antenna system. In an embodiment of the invention, the antenna system of the present invention may be a high-gain, low-profile wide-band antenna. Advantageously, the antenna system of the present invention may include a plate with reflecting elements to form a reflectarray antenna suitable for mounting on an aircraft. The reflectarray antenna of the present invention may be formed from a planar array of waveguides which may operate as a low loss, wide-band reflecting elements. Individual waveguides may be designed to scatter an incident field while impressing appropriate phase shifts in order to form a plane wavefront at the array aperture to produce a desired output signal. Waveguides may include ridges to employ vertical and horizontal polarization across a wide bandwidth operable at a high frequency, such as 10 GHz to 30 GHz.