Patent ID: 8872705

Claim:
A dual-band mobile communication device, comprising a ground plane and an antenna, the antenna being located on a dielectric substrate close to the ground plane, and the antenna having a first frequency band and a second frequency band, the antenna comprising: a feeding portion comprising a first end and a second end, wherein the second end is an open end, wherein a length of the feeding portion is essentially one quarter-wavelength of a center frequency of the second frequency band, wherein the first end of the feeding portion is a feeding point of the antenna, and wherein the feeding portion generates the second frequency band; and a shorted radiating portion, wherein a length of the shorted radiating portion is at least twice the length of the feeding portion, wherein the length of the shorted radiating portion is essentially one quarter-wavelength of the a center frequency of the first frequency band; wherein a first end of the shorted radiating portion is shorted to the ground plane, wherein a second end of the shorted radiating portion is an open end, wherein the shorted radiating portion comprises a first linear section terminating in the second end, with the first linear section extending in a first linear direction towards the second end of the shorted radiating portion; wherein the feeding portion comprises a second linear section terminating in the second end of the feeding portion, with the second linear portion extending in a second linear direction towards the second end of the feeding portion; wherein the shorted radiating portion comprises multiple bends, wherein the first linear direction essentially extends parallel to, alongside, and in a same direction as the second linear direction; wherein the second linear section is between the ground plane and the first linear section, wherein the first linear section and the second linear section are parallel to the ground plane; wherein a coupling gap exists between the first linear section and the second linear section; and wherein the shorted radiating portion is capacitively excited by the feeding portion to generate the first frequency band.