Design analysis of compact dual-band microstrip RFID reader antenna

RFID excelled in automatic identification and data collection industry through its speed, agility and endurance. An analysis of the design of a single-layered microstrip antenna comprising a single patch on the top layer with slots on the radiating edges to obtain dual-band RFID reader operation at free ISM bands of 2.45 GHz and 5.8 GHz is presented in this letter. The antenna has a compact appearance and with the help of single microstrip feed line the radiating patch has a dimension of 19 mm × 29 mm. A good impedance bandwidth of 115 MHz has been achieved form 2.395 GHz to 2.50 GHz for the lower band, while the upper band covers 600 MHz (from 5.40 GHz to 6.00 GHz). The proposed antenna shows stable radiation characteristics for the frequencies of interest. Furthermore, an extensive parametric study was performed to realize the relationship between the resonance frequencies in the two bands and different parameters which is helpful for advancement of the antenna design.