Patent attributes
An antenna system includes a system ground and two antenna units. The two antenna units are individually disposed on two opposite sides of the system ground and symmetrically mirrored with each other. Each antenna unit includes a circuit board, a first antenna pattern and a second antenna pattern. The first antenna pattern is disposed at one side of the circuit board. The first antenna pattern resonates to generate a first high resonant frequency. The second antenna pattern is disposed at the other side of the circuit board. The first antenna pattern resonates with part of the second antenna pattern to generate a low resonant frequency.