Electrically Small Supergain Arrays

The theory, computer simulations, and experimental measurements are presented for electrically small two-element supergain arrays with near optimal endfire gains of 7 dB. We show how the difficulties of narrow tolerances, large mismatches, low radiation efficiencies, and reduced scattering of electrically small parasitic elements are overcome by using electrically small resonant antennas as the elements in both separately driven and singly driven (parasitic) two-element electrically small supergain endfire arrays. Although rapidly increasing narrow tolerances prevent the practical realization of the maximum theoretically possible endfire gain of electrically small arrays with many elements, the theory and preliminary numerical simulations indicate that near maximum supergains are also achievable in practice for electrically small arrays with three (and possibly more) resonant elements if the decreasing bandwidth with increasing number of elements can be tolerated.Comment: 10 pages, 11 figures, submitted to IEEE Transactions on Antennas and Propagation (December 2006

Small end-fire superdirective folded meandered monopole antenna array

International audienceIn this letter, we present a compact four-element superdirective antenna array operating at 900M Hz frequency band. In this antenna, only one element is excited while the others are parasitic-loaded elements. The antenna total dimensions are 231 × 122mm 2 and it has a total directivity of 11.6dBi and radiation efficiency of 46%. This antenna is significantly compact compared with others presenting the same directivity

РЕАЛІЗАЦІЯ ІНФОРМАЦІЙНИХ ЛОГІСТИЧНИХ СТРУКТУР У КЛАСАХ ЗАДАЧ СИСТЕМ МАСОВОГО ОБСЛУГОВУВАННЯ

The articles in concerned with the problems of realization of information logistics structures in task classes of mass service systems. The samples of building the mathematical palterrs and developrug the algorithms of effective information service of logistics systems are given.Розглядаються проблеми реалізації інформаційних логістичних структур у класах задач систем масового обслуговування. Наведені приклади побудови математичних моделей і розробки алгоритмів ефективного інформаційного обслуговування логістичних систем