Electromagnetic analysis of beam-scanning antenna at millimeter-wave band based on photoconductivity using Fresnel-zone-plate technique

The proposed antenna is a Fresnel-zone-plate antenna (FZPA) in the Ka band that scans the beam of millimeter wave source. The antenna includes a semiconductor wafer (silicon, gallium arsenide) in which a spatially varying density of charge carriers is selectively established through selective optical illumination using a pulse laser. It is shown that the beam of the antenna can be scanned through the space by reconfiguring the masking of the wafer. The beam scanning is done in the transmission mode. The analysis of the far-zone radiation characteristics is presented using physical optics. Results for the antenna gain, the efficiency, and the co- and cross-polar patterns are given.