An antenna structure includes a metallic member and an extending section. The metallic member includes a front frame, a backboard, and a side frame. The side frame defines a slot. The front frame defines a first gap and a second gap communicating with the slot and extending across the front frame. A portion of the front frame between the first gap and the second gap forms a radiating section. Current enters the first radiating section from the first feed portion and flows through the first radiating section and towards the first gap and the second gap to generate radiation signals in a first frequency band and a second frequency band; the current flows through the extending section to generate radiation signals in a third frequency band. A wireless communication device using the antenna structure is provided.

An antenna structure includes a metallic member and an extending section. The metallic member includes a front frame, a backboard, and a side frame. The side frame defines a slot. The front frame defines a first gap and a second gap communicating with the slot and extending across the front frame. A portion of the front frame between the first gap and the second gap forms a radiating section. Current enters the first radiating section from the first feed portion and flows through the first radiating section and towards the first gap and the second gap to generate radiation signals in a first frequency band and a second frequency band; the current flows through the extending section to generate radiation signals in a third frequency band. A wireless communication device using the antenna structure is provided.

A device for forming a beam of an antenna array, the device including: an antenna array having a plurality of spatially distributed elements; a processor for selectively switching said elements between first and second states wherein, in said first state, said elements are configured to receive an incoming signal; and a receiver operatively associated with said antenna array and said processor for generating a reference signal, mixing said incoming signal with a modified reference signal to generate a mixed signal and summing the mixed signal over a predetermined period to generate an accumulated signal, wherein said reference signal is modified prior to being mixed with said received signal such that said accumulated signal is indicative of the direction and magnitude of the beam of the antenna array.