An electronic apparatus with an antenna, an anti-jamming system and a method are disclosed. The electronic apparatus comprises a casing and the antenna. The antenna is composed of a patterned metal thin film and a carrier and provided for processing a wireless signal. The casing and the antenna are made by injection molding. When the electronic apparatus has a display device, the anti-jamming system can modulate a clock signal generated by the display device to prevent the multiplication of clock signal from interfering with signals within an operating band of the antenna.