FIBEROPTIC PRISM TRUE TIME-DELAY ANTENNA FEED

We describe and present experimental results for a novel and elegant o ptical-control technique for implementing a true time delay function f or array antennas. A microwave signal is transmitted on a wavelength-t unable optical carrier through a fiber-optic prism-a set of nominally equal-delay fibers with differing net dispersion-to photodetectors tha t feed each antenna element. The relative interelement time-delay (bea m angle) adjustment is accomplished by tuning the optical carrier wave length. Measured antenna patterns of a two-element array clearly demon strate beam steering and true time-delay operation over a two-octave b andwidth of 2-8 GHz.