Low-Profile Magnetic Shielding for Circuit Board Electronics

Electronic components sensitive to magnetic fields, such as superconducting digital electonics, require magnetic shielding from ambient fields and magnetic pulses. While enclosures of high permeability magnetic materials are commonly used to achieve passive flux shunting, the structures are substantially larger than the circuitry being protected. For military and commercial satellites, this adds undesired volume and weight. A substantially lower-profile solution is proposed here in which stray magnetic fields are both passively shunted and actively nulled. The shielding assemblies are small and can be used alone or in arrays to cover desired areas of electronic components on printed circuit boards. The assemblies are expected to produce substantial magnetic-field reductions and yet have at least three times less the volume and weight of a purely passive shield.