Eight beam prototype fiber optic Rotman lens

Abstract

A prototype fiber optic Rotman lens was designed and fabricated using silica glass planar waveguide couplers, and precision lengths of single mode optical fiber. The form-factored photonic beamformer was integrated with a wideband linear antenna array to provide eight beam pointing directions corresponding to /spl plusmn/7.5/spl deg/, /spl plusmn/22.5/spl deg/, /spl plusmn/37.5/spl deg/, and /spl plusmn/52.5/spl deg/. Azimuthal antenna patterns were recorded for all beams at frequency increments of 500 MHz over the 2.0 to 4.0 GHz band to demonstrate squint free performance.