Electromagnetic resonance coupler

An electromagnetic resonance coupler for contactlessly transmitting a high frequency signal between a first resonant wiring and a second resonant wiring, the electromagnetic resonance coupler comprising:

• a transmission substrate;
• a reflective substrate facing the transmission substrate;
• the first resonant wiring having an open loop shape having a first opening;
• a first input/output wiring connected to the first resonant wiring;
• the second resonant wiring provided inside the first resonant wiring and having an open loop shape having a second opening;
• a second input/output wiring connected to the second resonant wiring, the first resonant wiring, the first input/output wiring, the second resonant wiring, and the second input/output wiring being provided on the transmission substrate;
• and
• a reflection wiring provided on the reflective substrate and having a open loop shape having a third opening,
• wherein, when viewed in a direction perpendicular to a main face of the transmission substrate,
• an overlapping portion of the reflection wiring and the first resonant wiring has an open loop shape having the first opening and the third opening, and
• an overlapping portion of the reflection wiring and the second resonant wiring has an open loop shape having the second opening and the third opening.