Monolithic Phase Shifter Study

Modeling and testing of monolithic coplanar waveguide (CPW) phase shifters using both optical and Schottky-contact control techniques have been performed. Simulation work on a periodically illuminated structure has been completed, showing that some improvement in performance may be possible, although with a reduction in frequency bandwidth. CPW transmission lines have been fabricated on semi-insulating GaAs, on lightly and heavily doped epi GaAs, and on AlGaAs/GaAs heterostructure, and electrical characterization has been performed. Both Schottky-bias controlled mechanism, using constant D.C. bias while using optical control has also been developed, which has yielded the best experimental performance to date for a distributed CPW phase shifter.