A 4-Bit optical true time-delay for 10-GHz phased array antennas using optical MEMS switches and fiber-optic delay lines

Abstract

A 4-bit true time-delay (TTD) for 10-GHz linear phased-array antenna (PAA) systems using the optical microelectromechanical (MEMS) switches and fiber-optic delay-lines were investigated. Each matrix element consisted of a 2x2 optical MEMS switch and a single-mode fiber-optic delay-line connected between cross parts of the MEMS switch. The optical pulses injected into the feeder were reflected from both cleaved ends of fiber attached to the output port of the last MEMS switches. The results show that power variation could be equalized either optically using variable optical attenuators or electrically by adjusting gain of RF amplifiers located at the photo-detector output.