Axial Ratio Improvement of Circularly Polarized Antenna Using Parasitic Elements for 5G Applications

Table 1

Comparison with state-of-the-art dual-CP antennas.

Ref.	Antenna size (mm^3)	Antenna type	Design methodology	IBW for (GHz)	3 dB ARBW (GHz)	Peak gain (dBiC)	Application
[3]		Stacked configuration	Sequential phase rotation	1-2.35 (80%)	1.5-1.9 (23.5%)	4.8	GPS/CNSS/RFID
[4]		Microstrip antenna	Using PIN diodes	3.4-3.72 (9%)	Has a Resonance at 3.6 GHz	4.8	5G
[5]		Patch antenna	RF switches	2.4-2.57 (7%)	2.38-2.6 (8.8%)	8.7	WLAN
[6]		Patch antenna	Switch parasitic pins	2.29–2.69 (16%)	0.15 GHz (6.1%)	8.7	WLAN
[7]		Patch antenna	Using PIN diodes	27–29 (7.1%)	27.2-28.3 (4%)	6	5G
[8]		Printed dipoles	Sequential phase rotation	1.95-2.75 (34%)	2.05–2.27 (10.2%)	8	—
[9]		SIW antenna array	CP antenna elements	27.4–28.94 (5.5%)	27.7–28.8 (3.9%)	13.52	mm-wave
[10]		Printed monopoles	Mirrored image	3.4-3.8 (11.11%)	3.4-3.8 (11.11%)	5	5G
[11]		Printed monopoles	Grounded stubs	5.2-6.3 (19.13%)	5.2-6.3 (19.13%)	5.8	ISM
[12]		Dipole with integrated balun	Sequential phase rotation	3.3–4.2 (34.7%)	3.65–3.81 (4.3%)	9.52	5G
[13]		Printed dipoles	Quadrature wideband coupler	1.70–2.82 (50%)	1.70–2.82 (50%)	7.2	BTS
[10]		Printed monopoles	Elliptical-shaped resonator	3.4–3.8 (11.11)	3.4–3.8 (11.11)	5	5G
Prop.		Dipole with integrated balun	Using 90° hybrid coupler in the feed network	3.19–4.12 (25.4%)	3.19–4.12 (25.4%)	6.78	5G