A Low-Profile Circularly Polarized Conical-Beam Antenna with Wide Overlap Bandwidth

Table 2

Comparison of the proposed and other conical-beam CP antennas.

Ref.	Dimension of the antenna ()	Impedance bandwidth	AR bandwidth	Overlap bandwidth
[18]		19.8% (2.27-2.77 GHz)	19.3% (2.25-2.73 GHz)	18.4% (2.27-2.73 GHz)
[19]		28% (4.9-6.5 GHz)	14.4% (5.8-6.7 GHz)	11.4% (5.8-6.5 GHz)
[20]		19.6% (2.16-2.63 GHz)	27.4% (2.05-2.7 GHz)	19.6% (2.16-2.63 GHz)
[21]		21.9% (5.5-6.85 GHz)	15.9% (5.8-6.8 GHz)	15.9% (5.8-6.8 GHz)
[22]		17.5% (5.7-6.75 GHz)	26.5% (5.19-6.78 GHz)	17.5% (5.7-6.75 GHz)
This work		35.6% (4.97-7.14 GHz)	30.1% (4.97-6.73 GHz)	30.1% (4.97-6.73 GHz)

is the free space wavelength at the starting frequency of the overlap bandwidth.