Patent ID: 8378917

Claim:
A proximity antenna comprising: an approximately annular substrate comprising an insulating material; a first wiring pattern formed alone the shape of the substrate on one surface of the substrate, the first wiring pattern being approximately annular and having one end and the other end; and a second wiring pattern formed along the shape of the substrate on the other surface of the substrate, the second wiring pattern being approximately annular and having one end and the other end, wherein the one end and the other end of the first wiring pattern and the one end and the other end of the second wiring pattern are disposed so that the first wiring pattern and the second wiring pattern are interdigitally coupled with each other in case both of the other end of the first wiring pattern and the other end of the second wiring pattern are supplied with a ground level, and the one end of the first wiring pattern and the one end of the second wiring pattern are connected to a pair of signal lines used in a differential, transmission system.