Characterization of Indium Tin Oxide (ITO) PET Films for the Development of an Image Quality Tool (IQT)*

To ensure the safety of travelers worldwide, airports use active millimeter wave Advanced Imaging Technology (AIT) systems to detect potential threats such as explosives. There is a need for an Image Quality Standard (IQT) to quantitatively guarantee the functionality of the AIT systems. Through the establishment of an IQT standard, it can be assured that an AIT is functioning the same when manufactured, pre- and post-certification, and at any point throughout its lifetime.

Our research proposes Indium Tin Oxide (ITO) coated polyethylene terephthalate (PET) films as an IQT standard for the range of 60-90 GHz, which overlaps with the frequency range of AIT systems currently in use. Five ITO-PET films of various resistivities are evaluated using free space reflection measurements. These films show stability over the 60-90 GHz range and an inverse relationship between surface resistivity and reflectivity is established. This stability confirms the potential for ITO-PET films to act as a standard in evaluating the functionality of IQT systems.