2-D Beam Focusing Control Based On Passive Frequency Selective Surface (Fss)

In this paper, the novel design methodology of 2-D beam focusing control based on passive frequency selective surface (FSS) is proposed and described. The beam focusing antenna is composed of 1-D array source and 2-D FSS having a good transmittance and a full transmission phase variation of 360 degrees. The 2-D FSS is designed to make the phase of wave radiated by one source be in-phase, so the transmission phase of the 2-D FSS is concave in itself. Then, the designed 2-D FSS is integrated to the 1-D array source and the longitudinal and the transverse beam focusing controls can be achieved by changing the phase shape of the array source. The relation between the focusing point and the phase combination of the sources is analyzed by a parabolic formula, and the performance of the beam focusing control system is confirmed by both simulation and measurement. From both results, it is concluded that the focusing spot can be tuned longitudinally and transversely by the proposed methodology at 5.8 GHz. In addition, the electric field intensity of 1-D array source with 2-D FSS increases by about 35% compared to that of only 1-D array source.