Patent ID: 6471878
Filing Date: 2002-10-29
Classification: G01S,G06F,G08B

Abstract:
A method for forming a radio frequency responsive target, comprising the steps of:(A) depositing a first metallic film layer on a non-conductive substrate; (B) generating a pattern of thin dipoles, each of said thin dipoles having a position and m angular orientation within said pattern of thin dipoles; (C) depositing an etchant resistant pattern on top of said first metallic film layer, said etchant resistant pattern corresponding to a photographic image of said pattern of thin dipoles, said etchant resistant pattern having a thickness; (D) after step (C), applying a second metallic layer on top of said first metallic film layer, said second metallic layer occupying areas on said first metallic film layer where said etchant resistant pattern is absent, said second metallic layer having a thickness equal to said thickness of said etchant resistant pattern; (E) after step (D), removing said etchant resistant pattern in order to expose portions of said first metallic film layer, and (F) after step (E), simultaneously etching said second metallic layer and said portions of said first metallic film layer until said portions of said first metallic film layer have been removed from said non-conductive substrate; wherein said target is formed of said pat of thin dipoles, and wherein said thin dipoles produce a composite analog radio frequency signal in response to an interrogating signal.