Multibending antenna structure

A multibending antenna structure, comprising:

• a substrate;
• a grounding layer disposed on one side of the substrate;
• and
• a microstrip antenna layer disposed on another side of the substrate in opposite to the ground layer, the microstrip antenna layer comprising at least one radiation unit which is formed in a multibending shape and having a concave area, a total length of the radiation unit being equal to 0.8 to 1.2 time a length of a wavelength of an operation frequency, the radiation unit comprising an signal input end for receiving a signal input in order to emit an electromagnetic wave having a radiation energy,
• wherein each radiation unit comprises a head section, a first radiation section, a transition section, a second radiation section, and a tail section that are perpendicularly connected in a multibending shape;
• the first radiation section, the transition section, and the second radiation section form the concave area;
• the total length of the radiation unit is defined as a length from the head section to the tail section,
• wherein the head section, the first radiation section, the transition section, the second radiation section, and the tail section have an identical line width;
• a ratio of the line width and the length of the wavelength ranges from 1:10 to 1:30.