Deployable Wide-Aperture Array Antennas

Lyndon B. Johnson Space Center, Houston, Texas

Inexpensive, lightweight array antennas on flexible substrates are under development to satisfy a need for large-aperture antennas that can be stored compactly during transport and deployed to full size in the field. Conceived for use aboard spacecraft, antennas of this type also have potential terrestrial uses ? most likely, as means to extend the ranges of cellular telephones in rural settings.

A Wide Array of Four Radiating Antenna Elements and their transmission line would be made from flexible conductive materials on a flexible dielectric sheet. When not in use, the antenna could be rolled into a compact cylinder in the manner of a window shade.

Several simple deployment mechanisms are envisioned. One example is shown in the figure, where the deployment mechanism, a springlike material contained in a sleeve around the perimeter of a flexible membrane, is based on a common automobile

The deployable antenna may comprise multiple types of antenna elements. For example, thin profile antenna elements above a ground plane, both attached to the supporting flexible membrane, can be used to create a unidirectional boresight radiation pattern. Or, antenna elements without a ground plane, such as bow-tie dipoles, can be attached to the membrane to create a bidirectional array such as that shown in the figure. For either type of antenna element, the dual configuration, i.e., elements formed of slots in a conductive membrane, can also be used. Finally, wide bandwidth antennas or arrays can be formed in which the principal direction of radiation is in the plane of the membrane. For this embodiment, the set of elements on the membrane is arranged to form one or more traveling wave antennas. In this case, a noncon-ductive form of the perimeter springlike material is required to provide the deploying force.

This work was done by Patrick W. Fink, Justin A. Dobbins, Greg Y. Lin, Andrew Chu, and Robert C. Scully of Johnson Space Center. This invention is owned by NASA, and a patent application has been filed. Inquiries concerning nonexclusive or exclusive license for its commercial development should be addressed to