The invention relates to a chip card designed to communicate data in a contactless mode with a card reader operating at a reading frequency. The resonance frequency of the chip card may change according to the capacitance of the chip used in the contactless mode of the chip card. In order to be able to use various chips without changing the booster antenna design, the card antenna circuit is provided with a capacitance element such that the chip card including the card antenna circuit and the chip module has two different resonance frequencies, one of which being equal to, or lower than, the reading frequency and the other being equal to, or greater, than the reading frequency. This create a broadband wherein the reading frequency falls.