A multi-frequency antenna includes a microwave substrate, a first antenna unit, a second antenna unit, a third antenna unit and a grounding unit. The first antenna unit, the second antenna unit, and the third antenna unit are disposed on the microwave substrate surface. The grounding unit is disposed at an edge on the surface of the microwave substrate. The grounding unit is in connection with the second antenna unit. The second antenna unit and the third antenna unit are bent to form perpendicular structures to the microwave substrate. The compact arrangement reduces the physical footprint of the antenna module to enable fitment in a wide range of products having tight special constraint.