A device includes at least one ultra-small resonant structure; and shielding constructed and adapted to shield at least a portion of said ultra-small resonant structure with a high-permeability magnetic material. The magnetic material is formed from a substance selected from a non-conductive magnetic oxide such as a ferrite; a cobaltite, a chromite, and a manganite. The magnetic material may be mumetal, permalloy, Hipernom, HyMu-80, supermalloy, supermumetal, nilomag, sanbold, Mo-Permalloy, Ultraperm, or M-1040.