Patent ID: 7183987
Filing Date: 2007-02-27
Classification: G06K,H01Q

Abstract:
1. An antenna apparatus connected to a communication apparatus that makes data communication with a contactless integrated circuit card by electromagnetic inductive coupling, the antenna apparatus comprising: a loop coil for electromagnetic inductive coupling; and a magnetic member disposed to face a main side of the loop coil, opposite to a side of the loop coil facing the integrated circuit card, wherein the magnetic member has a specific permeability μ′ and product Ms·t of saturation magnetization Ms and thickness t thereof based on a range set for facilitating communications with the contactless integrated circuit card; wherein the magnetic member has a wide portion wider than an outermost width of a winding section of the loop coil and a narrow portion narrower than an innermost width of the winding section; and the wide portion of the magnetic member is disposed to face the main side of the loop coil, opposite to the side of the loop coil facing the integrated circuit card, with the narrow portion being penetrated through a center of the loop coil, while the narrow portion is disposed to face a main side portion of the loop coil, facing the integrated circuit card and where a winding interval of the loop coil is narrow.