A Broadband Circularly Polarized Antenna Based on Cross-Dipoles

Abstract

Abstract-In this paper, based on cross-dipoles, a right-handed circularly polarized (RHCP) antenna with both broad impedance and axial-ratio (AR) bandwidth is proposed. Moreover, metal vias and branches are loaded to the cross-dipoles aiming to decrease the size of the antenna. The measured results show that a broadband impedance matching bandwidth ranging from 1.83 to 3.42 GHz for S 11 less than −10 dB is obtained. Meanwhile, the 3-dB axial-ratio bandwidth is more than 29.0%, and the peak gain of the antenna is about 7.3 dBi with small variation at 2.5 GHz. A prototype is fabricated and measured for validating the design. The good agreements between the simulated and measured results show that the proposed antenna maybe a good candidate in circularly polarized (CP) antenna family.

A Wideband Circularly Polarized Slot-Loaded Dipole Antenna With L-Shaped Arms and Parasitic Patches

“…Gain (dBic) FBR (dB) Electrical dimension (λ0 at center frequency) [5] 63.6 29.0 about 7.3 > 11 0.58λ0 × 0.58λ0 × 0.22λ0 [6] 53.0 33.0 1.2-2.7 about 0 0.53λ0 × 0.53λ0 × 0.02λ0 [7] 57.0 47.8 6.0-7.5 > 14 0.78λ0 × 0.78λ0 × 0.25λ0 [8] 67.0 60.0 −6.1-7.6 > 15 1.03λ0 × 1.03λ0 × 0.12λ0 [9] 57.3 41.4 / > 6 0.97λ0 × 0.97λ0 × 0.52λ0 [10] 63.3 51.1 about 9.0 > 20 1.16λ0 × 1.16λ0 × 0.24λ0 Pro.…”

“…As shown in Figure 8, the measured antenna gains are between 5.6 and 9.8 dBic over the band of interest (1.71-3.22 GHz), and desired front-to-back ratios (FBRs) of better than 20 dB are also obtained. The comparisons of the measured performances between the proposed antenna and those previously reported antennas [5][6][7][8][9][10] are listed in Table 1. It is worth noting that the proposed antenna has wider impedance bandwidth and AR bandwidth than the other referenced designs except for the design in [8].…”

“…To improve the AR bandwidth, many effective approaches have been demonstrated and discussed by researchers. In the design presented in [5], cross-dipoles with metal vias and branches are employed to achieve a 3-dB AR bandwidth of 29.0%. In [6], by introducing overlapping square slotrings, the antenna can yield a 3-dB AR bandwidth of 33% and a 10-dB impedance bandwidth of 53% with bi-directional radiation.…”

Broadband circularly polarized tapered dipole antenna for GNSS applications

“…A broadband CP antenna that realizes 90 phase-shifted power feeding through a series-fed power division network is proposed in reference 11. In addition to changing the feed structure, impedance bandwidth and AR bandwidth of the antennas [12][13][14][15] were broadened by adding parasitic patches, slits, and rotating circular stubs, respectively. Finally, the FBR is also a problem to be solved.…”