Small biomimetic array for direction finding and superdirectivity

Satellite and terrestrial (wireless) communication systems require high functionality (i.e., direction finding, beam steering, reconfigurability, frequency agility, and broadband) to address multiservice, multiband, and multistandard operation in a confined small volume. Although there are existing technologies with such functionality, the associated devices are large and heavy, and often limited in functionality. However, recent developments in conformal miniature ultra-wideband apertures with phase amplification of the received/transmitted signal provide for a new direction in fulfilling the lofty goal of miniature antenna direction finding apertures. A way to overcome reduced resolution is to amplify the phase difference between adjacent elements. In this paper, we propose to enhance the phase difference between adjacent elements (as close as λ/10 apart) by controlling interelement coupling. The design is achieved by casting the array elements in a T- or π-resonator network. Optimization leads to an antenna-circuit structure that achieves phase amplification. This equivalent circuit mimics the hearing capabilities of some small insects (e.g., the parasitoid Ormia ochracea).