Design of a Miniaturized Wideband Disc Monopole Antenna Used in RFID Systems

This paper introduces an omnidirectional microstrip antenna operates at 2.45 GHz used for a radio-frequency identification (RFID) technology. The length of the proposed antenna is 36.5 mm and the width is 27 mm. The substrate material used as a base of antenna is FR-4 that has dielectric constant value of 4.3 and dielectric thickness value of 1.6 mm. At resonance frequency the return loss of the prpresented antenna is -34.8 dB. An appreciate directivity of 2.8 dB has been achieved with omnidirectional radiation pattern in addition to an acceptable efficiency of 66%. The designed antenna has a wideband frequency of 1.21 GHz in the frequency range of (2.14  3.35) GHz. The computer simulation technology (CST) microwave studio software is used for simulation. The proposed antenna was fabricated and its characteristics are measured using vector network analyzer (type MS4642A). The measured results are little bit difference with simulation results.