Patent attributes
An antenna substrate includes a substrate, a modulation/demodulation circuit, a printed antenna, a first switch circuit, and a second switch circuit. The printed antenna printed on the substrate includes a plurality of unit coils. The first switch circuit selectively switches to a state where a part or all of the plurality of unit coils are selectively and electrically connected in series, or a state where a part or all of the plurality of unit coils are electrically disconnected, in accordance with a first control signal inputted to the first switch circuit. The second switch circuit selectively and electrically connects a first end of any one of the plurality of unit coils to the modulation/demodulation circuit in accordance with a second control signal inputted to the second switch circuit.
