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.