US Patent 7432861 Dual-band antenna

A dual-band antenna (10) is provided. The dual-band antenna printed on a substrate (30) includes a transmission portion (120), a first radiator (140), a second radiator (160), a first grounded portion (180), and a second grounded portion (190). The transmission portion is used for feeding electromagnetic signals. The first radiator is electronically connected to the transmission portion for transceiving electromagnetic signals with a first frequency. The second radiator is electronically connected to the transmission portion for transceiving electromagnetic signals with a second frequency. The first grounded portion is disposed on a first surface of the substrate. The second grounded portion is disposed on a second surface of the substrate. A length of the second grounded portion is greater than that of the first grounded portion. An antenna assembly is also provided in the present invention.