US Patent 9729210 Chassis NFC antenna booster

A communication device used for near filed communications (NFC). The device includes circuitry that generates a differential signal for communication with an analog front end of the device. The analog front end includes an impedance matching network and an antenna. The antenna is disposed at a predetermined distance away from the boundary of a battery compartment. The antenna forms a single loop around the battery compartment and is coupled to the matching network either in a differential manner or a single ended manner. The communication device includes a protective back casing that is either metallic or plastic in nature. With the single loop antenna configuration, both types of back covers enable efficient NFC.