A booster antenna (BA) for a smart card comprises a card antenna (CA) component extending around a periphery of a card body (CB), a coupler coil (CC) component at a location for an antenna module (AM), and an extension antenna (EA) component contributing to the inductance of the booster antenna (BA). At least one of the components may have a pitch which is different than one or more of the other components. A method of wire embedding is also disclosed, by controlling a force and ultrasonic power applied by an embedding tool at different positions on the card body (CB).