Low cost material for multi-bit remote sensing

摘要

Multiple bits of information may be conveyed by passive target material incorporating filaments of magnetizable material having different magnetization functions and, in particular, different coercivities. Detection of the presence or absence of the individual filaments may be done remotely by measuring induced flux B as a function of an externally imposed magnetic field waveform and subjecting the measured induced flux signal to differentiation or Fourier transform techniques.