An Active Phased Array With Optical Control And Beam-scanning Capability

Radar, missile guidance and communications systems typically have rigid spatial constraints. However, in conventional systems, large amplifiers and motors are requirtxl to transmit high power and scan the antenna main beam, respectively. Waveguide typically is used because it has low loss and high power capability, but is bulky and not easily routed. These obstacles have: led to continuing research in system and component designs to produce integrated and compact designs. One method that has shown promise in remedying some of these problems is the active antenna array, which integrates active components directly into the antenna platform. Research has shown that power can be combined quasi-optically in active antenna arrays [I]-[3]. Also, the main beam can be electronically scanned by controlling the phase between adjacent antenna elements [4]-[5]. Recently, an active phased array with optical input and beam-scanning capability was reported [6]. In [6], a microwave reference signal is prlovided through an optical fiber link, but array control signal are provided electronically. In this work, a novel method of controlling individual array elements for beam-scanning is accomplished by optically illuminating commercially available MESFET transistors.