A handheld device comprises a casing acting as a protective supporting framework of the handheld device. A circuit board mechanically supports and electrically connects with each other electronic components of the handheld device and is configured to be embedded into the casing. At least one wireless communications circuit transmits signals and data from the handheld device and is carried by the circuit board. A flex-antenna assembly is electrically coupled to the wireless communications circuit for sending and receiving the signals and data, defines flexible dielectric and conductive layers of the flex-antenna assembly disposed adjacent to each other, and is embedded into the circuit board.