A multilayer compact-size UWB-UHF antenna system for novel RFID applications

Hybrid UWB-UHF antennas are deemed important for combining localization with energy harvesting. This paper enhances the design of existing work and proposes a new dual-band small-size/low-profile device for simultaneous RF energy harvesting as well as communication and localization functions. This is achieved by having the localization provided in the lower European UWB band 3.1 to 4.8 GHz, while the RF energy is harvested in the UHF RFID 868 MHz band; thus dealing with less path losses with respect to higher frequency harvesting systems (e.g. ISM band), i.e. resulting in more available RF power. Electromagnetic and nonlinear circuit simulation shows that only 43×43×6 mm³ in dimensions is needed for this dual band antenna with RF to DC conversion efficiency in the range of 50-60%, which is state-of-the-art performance for exploiting the capabilities of such antennas. Implementation of this antenna, including matching/feeding circuitry, is under development to prove real-indoors performance.