Résumé
A new concept of letter identification by use of RF wave is presented in this paper. Since letters have various shapes, their Electromagnetic signature can be identified independently. Considering the Latin alphabet, its 26 letters can be identified for a given font size. To measure the electromagnetic signature of each letter, a wideband measurement set-up has been used with a frequency span until 10 GHz. It is based on a bi-static radar system with a pulse generator as source, compatible with UWB regulations, and a real time sampling oscilloscope as receiver. The Arial letters used in this work are 48 mm in height and were realized on a flexible Kapton substrate. The main application of metallic letters is in item identification. But the greatest interest of using metallic letters is based on combining the visual identification, with the remote Electro Magnetic identification, also possible outside the line of sight.