In this letter, a wide-band antenna with dual open rings resonator (DORR) is presented for ambient radio frequency (RF) energy harvesting applications. The proposed antenna is designed to harvest RF energy at DCS1800, UMTS/LTE, and Wi-Fi bands (1.7–2.65 GHz). The DORR produces a strong coupling effect and leads to more current paths, thus contributing to a wider bandwidth. The measured bandwidth is from 1.68 to 2.80 GHz with 50% fractional bandwidth. The measured gains are 3.5, 5, and 5 dBi at 1.83 GHz (DCS1800), 2 GHz (UMTS/LTE), and 2.45 GHz (Wi-Fi), respectively. Moreover, over 90% radiation efficiency and larger than 3 dBi gain are achieved for the operating bands. The antenna can be used for RF energy harvesting and various communication applications.