Compact CPW-fed dual-band uniplanar antenna for RFID applications

This paper presents a novel dual-band uniplanar monopole antenna fed by Coplanar Waveguide (CPW) line suitable for Radio Frequency Identification (RFID) applications especially designed for RFID readers and it operates at 2.45 GHZ and 5.8 GHZ. This antenna is designed with reasonable gain, low profile and low cost achievement. The proposed antenna benefits from the advantages of the CPW line to simplify the structure of the antenna into a single metallic level, hence making it easier for integration with integrated microwave circuits. The simulation results carried out by ADS from Agilent technologies and CST Microwave Studio electromagnetic solvers, demonstrate that we have good performances in term of return loss, gain, radiation pattern and efficiency for the desired frequency bands. This antenna has a total area of 30×45mm² and mounted on an FR4 substrate with constant dielectric permittivity 4.4 and thickness of 1.6mm and loss tangent of 0.025. The simulated return loss less than -10 dB at the lower band is about 200 MHz and for the upper band reaches about 400 MHz, which covers the RFID standards. The gain obtained into simulation of this antenna is 1,9 dB at 2.45GHz and 2,8 dB at 5.8 GHz.