Compact 2*1 Reader Array Antenna Operating in ISM Band for RFID Applications

Instrumentation, Signals and Physical Systems (I2SP) Team, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco

Abstract

This paper proposes a compact 2*1 reader array antenna for RFID system having high directivity, good gain, and good reflection coefficient. The structure consists of two main radiating rectangular patch antennas connected in parallel with a common impedance of (50 Ω). These patches are printed on an RT/duroid 5880 substrate possessing a dielectric constant ε_r equal to 2.2 and 0.0009 as a loss tangent. It operates in ISM (Industrial, Scientific and Medical) band with a resonant frequency of 5.8 GHz. The structure is implemented on a compact size of 38.77× 59.44× 1.6 mm³ equivalent to an electrical size of 0.74λ₀× 1.14λ₀× 0.03λ₀, where λ₀ is the free-space wavelength at the resonant frequency. The gain achieved by the final design of the proposed antenna is equal to 9.83 dB, the directivity is around 9.99 dB and the coefficient of reflection (S₁₁) is equal to -49.48 dB. The proposed antenna design is optimized and simulated using Computer Simulation Technology software (CST Microwave Studio).