Antenna system and mobile terminal

An antenna system, comprising a mainboard having a system ground, a metal frame disposed around the mainboard and being closed-loop without any breakpoints, a first wire, a second wire, a third wire, a feed terminal, and a ground terminal;

• the system ground is electrically connected to the metal frame;
• the first wire is connected to the feed terminal and is opposite to and spaced apart from the metal frame, so that the first wire forms a first antenna unit;
• the second wire is connected to the ground terminal and is spaced apart from the first wire, and the second wire and the first wire are at least partially opposite, the first wire is disposed at an outer side of the second wire and surrounds the second wire so that the second wire and the first wire are coupled with each other, to form a second antenna unit;
• and
• one end of the third wire is connected between the feed terminal and an end of the first wire, and the other end is connected to the metal frame, so that the first wire is electrically connected to the metal frame, to form a third antenna unit.