The proposed LC structure is comprised of a flexible insulative layer folded back on itself about a predetermined foldline, said insulative layer having on one surface an electrically conductive layer configured to form first and second alike planar multi-turn spirals which, in a like folded superposition,...http://www.google.com.hk/patents/US5291180?utm_source=gb-gplus-share專利 US5291180 - LC structure useful in radio frequency security systems
