Two-branch broadband antenna

A two-branch broadband antenna comprising:

• a ground plane;
• and
• a radiating portion, which is substantially a planar structure, comprising:
• a first radiating arm with length of 0.25 times of a first center frequency about 700 MHz, being a first U shape, the first radiating arm comprising:
• a first part having a closed end located near an edge of the ground plane, which is a feeding portion of the antenna;
• a second part extended from the first part and perpendicular to the first part;
• a third part extended from the second part and parallel to the first part;
• and
• a fourth part extended from the third part and perpendicular to the first part and having an open end;
• and
• a second radiating arm with length of 0.25 times of a second center frequency about 500 MHz being a second U shape, opening of the second U shape being opposite to opening of the first U shape, the second radiating arm comprising:
• a fifth part perpendicular to the first part and having a closed end connected to the first part
• a sixth part extended from the fifth part and parallel to the first part;
• a seventh part extended from the sixth part and perpendicular to the first part;
• an eighth part extended from the seventh part and parallel to the first part;
• and
• a ninth part extended from the eighth part and perpendicular to the first part and having an open end extended toward the open end of the fourth part with a predefined distance;
• wherein the radiating portion is not connected to the ground plane.