A new G-type structure of tri-band antenna is designed. It is suitable for individual combat devices and 3G/4G communication network. The antenna working frequency bands cover GSM, 3GTDD and IEEE 802.11a with 1.805-1.820 GHz, 1.880-1.900 GHz, and 5.725-5.850 GHz, respectively. This designed art can be applied to multi-band communication system, especially to the individual combat, as well as to the 3G/4G network. Very good quality of this antenna is obtained, such as light weight, small size, low profile and easy manufacture, etc.