Electrically Tunable HPM Phase Shifter for Naval Applications

The Navy needs high-power electrically tuned phase shifters to form high-power microwave (HPM) antenna arrays with electronic beam steering capability. In the proposed Phase I STTR, Physical Sciences Inc will collaborate with The University of Massachusetts-Amherst to develop novel electrically tunable dielectric materials with high breakdown strength, fast switching and low loss tangent. This effort will also bring the capability to produce microwave optimized tunable dielectric materials to the United States, rather than relying on foreign sourced materials. PSI will develop a waveguide-based phase shifter incorporating this material with >100 MW power handling, >1800°/s tuning agility, and a phase shifting figure-of-merit > 720 °/dB. Phase I will conclude with a physical prototype of the device and a differential phase shifter per insertion loss measurement. This technology has the potential to replace complex and expensive mechanically steered apertures with arrays of electrically tuned, low insertion loss X-band phase shifters. During Phase II, PSI will pursue two fabrication approaches for phase shifter prototypes incorporating tunable dielectric material. Once reliable manufacturing of full-length phase shifters is demonstrated, PSI will verify power handling with high peak power X-band magnetrons. PSI will also demonstrate high average power capability with temperature compensation for improving phase stability. Operational resilience testing will include humidity, altitude pressure, and min/max temperature qualification. Finally, antenna array power handling will be demonstrated at the end of the program using a high-power X-band source. An antenna subarray comprising >16 elements will be scanned in a far-field range to demonstrate >40° beam scanning in Azimuth and Elevation. The program will complete with fabrication and test of a full-scale array with >24 dBi gain on boresight.