Improved Magnetic Shielding for Superconductor Electronics

HYPRES has developed and demonstrated a family of wideband digital-RF receiver systems for applications in satellite and RF communications, signal intelligence and electronic warfare. In the heart of these systems are ultrahigh speed circuits of superconductor digital electronics. For a high fidelity operation, superconductor electronics needs magnetic environment that attenuates magnetic fields associated with Earth, system platform, and low frequency magnetic interference. This proposal focuses on the development of the novel approach to magnetic shielding of electronics – active magnetic cancellation. It is proposed to develop a hybrid magnetic shielding system comprised of a conventional mu-metal shield and a system of active canceling of the residual fields inside the shield. The system will include high-sensitivity magnetic sensors based on superconducting quantum interference filters – devices which can sense the absolute zero of magnetic field – and a feed back system with thin wire coils for active canceling. It is expected to achieve a factor of 100 improvement in the performance of such a magnetic environment in comparison with the existing passive magnetic shielding. When developed the active magnetic shielding system will become an integral part of the cryogenic package of all HYPRES digital–RF systems for DoD and commercial applications.