Single-Arm Archimedean Spiral Antenna with Broadband Circular Polarization

Table 1

Comparisons between spiral antennas in different studies.

Literature	Antenna circumference	Cavity height	Impedance bandwidth	AR bandwidth
[5]	0.84λL	0.13λL	1 : 5.4	1 : 4.8
[12]	2.14λL	0.07λL	1 : 3.3	1 : 3.3
[14]	0.83λL	0.07λL	1 : 3.0	1 : 3.0
[23]	1.57λL	0.13λL	1 : 2.5	—
[24]	1.12λL	No cavity	1 : 2.3	1 : 1.6
[25]	1.43λL	0.12λL	1 : 4.4	1 : 3.0
Ours	1.27λL	0.29λL	1 : 10.0	1 : 5.0