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Fig. 1. (Color online) (a) Illustration of the measurement setup for forgery detection of banknotes. The microwave signal is generated by the signal generator and falls through the waveguide onto the device under test (DUT) after being amplified by the power amplifier. The light emitted from the light emitting diode (LED) is left circularly polarized by a sheet polarizer and recorded by the camera after being reflected and elliptically polarized by the optical indicator (OI). The OI is composed of a glass substrate coated with indium tin oxide (ITO) thin film. (b) The photo of the measurement setup.
New Phys.: Sae Mulli 2022;72:953~958