Affiliations: School of Microelectronics, Xidian University, Xi'an, Shaanxi, China
Correspondence:
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Corresponding author: Xiaoming Li, School of Microelectronics, Xidian University, 710071 Xi'an, Shaanxi, China. E-mail:wangb@xidian.edu.cn
Abstract: A low profile planar monopole antenna with a small stub
fed by a bent microstrip line with high gain is presented for RFID reader
applications. The proposed antenna operates in microwave band of RFID,
namely, 2.4 GHz band and 5.8 GHz band. A wide impedance bandwidth of 820 MHz
has been achieved from 2 GHz to 2.82 GHz for the lower band, while the upper
band covers 500 MHz from 5.6 GHz to 6.1 GHz. This paper minimizes the size
of the antenna through modifying L-shape microstrip feed line. The antenna
has a compact size of 40 mm × 37.5 mm × 1.6 mm, however, with a
high gain critical for RFID reader applications. The antenna achieves 4.3
dBi and 8.1 dBi in 2.4 GHz band and 5.8 GHz band, respectively. Furthermore,
crucial parameters are investigated to examine the effects of the antenna
parameters on reflection coefficient as well as the impedance bandwidth of
the antenna.
Keywords: Compact antenna, modified L-shape, dual band
