A Dual-band Broadband Circular Polarized Antenna for Radio Frequency Identification Reader
A compact dual-band wideband circularly polarized antenna for Radio Frequency IDentification (RFID) reader is designed. The antenna consists of a curved rectangular patch, an L-shaped patch, and a triangular floor, which is fed through a microstrip line. The two radiation patches control the high and low frequency bands independently, and their axial ratio bandwidth can also be adjusted independently. The triangular floor can change the transverse current and the longitudinal current, so as to change the ratio of the transverse current and the longitudinal current to achieve circular polarization performance. The antenna dimensions are 0.92λ0 ×0.92λ0 ×0.0064 λ0(λ0is the free space wavelength at 2.40 GHz). The measurement results show that the proposed antenna achieves an impedance bandwidth of 49％ (0.77～1.27 GHz) and an axial ratio bandwith of 46％ (0.84～1.34 GHz) in the Ultra High Frequency (UHF) band, and achieves 47.5％(1.54～2.50 GHz) impedance bandwidth and 24.2％ (1.96～2.50 GHz) axial ratio bandwidth in Wireless Local Area Networks (WLAN) band. It can completely cover UHF and WLAN two frequency bands and has good radiation characteristics. Compared with other dual-frequency circular-polarized antennas, the antenna has compact structure and simple design, avoids the use of complex feed network, and has a wide bandwidth of 3 dB axial ratio.
Dual bandBroadbandRadio Frequency IDentification (RFID) reader antennaCircularly polarized antenna
万方数据
维普
