Patent ID: 7274297

Claim:
An RFID tag, comprising: an antenna substrate comprising an insulative layer and a conductive layer, the insulative layer of the antenna substrate comprising a first surface and a second surface opposed to the first surface, the conductive layer of the antenna substrate carried by the second surface of the insulative layer of the antenna substrate, the conductive layer of the antenna substrate patterned to form a slot antenna; a circuit substrate comprising an insulative layer and a conductive layer, the conductive layer of the circuit substrate patterned to form a circuit including an antenna line, a transformer, and a ground line, each conductively coupled to one another and physically formed in a plane defined by the conductive layer of the circuit substrate; and a semiconductor device electrically coupled to the circuit, wherein the antenna substrate and circuit substrate are coupled such that at least one portion of the slot antenna is electro-magnetically coupled through the insulative layer of the circuit substrate to at least one portion of the circuit without an electrical current path therebetween, to provide signals between the slot antenna and the semiconductor device.