GTRI reconfigurable aperture design

Researchers at the Georgia Tech Research Institute (GTRI) have been investigating a reconfigurable aperture concept by which the current distribution on an antenna can be controlled for the purpose of changing the aperture's function during operation. The geometry of the particular aperture being developed is shown. It consists of electrically small metallic pads connected by switches (FETs or MEMS) with a single feed point on the aperture. To illustrate the use of the switches to configure the aperture, certain switches are closed to form a bowtie pattern. GTRI anticipates that such an aperture will enable the following adaptations: (1) switching between broadband, low-gain operation and narrow-band, high-gain operation; (2) steering of the pattern from broadside; and (3) switching between omni-directional and directive horizontal patterns. This paper discusses the technical challenges in making this aperture a reality, how these challenges might be overcome, and the performance of the prototypes.