A Millimeter-Wave Wideband Circularly Polarized Planar Spiral Antenna Array with Unequal Amplitude Feeding Network

Table 3

Comparisons to reported 2 × 2 mmWave wideband CP antenna arrays.

Ref.	Fre. (GHz)	Feed type	IBW (%)	ARBW (%)	Structure	Gain (dBic)
[2]	61	SRP in MSL	16	5.0	Single feed, 1 layer-3D	14
[6]	28	SRP in SIW	23.3	7.7	Single feed, 2 layers-PCB	10.8
[7]	10.3	SRP in SIW	19.2	14.1	Single feed, 2 layers-PCB	13.48
[9]	45.5	SRP in SIW	14.7	14.7	Dual feed, 2 layers-PCB	10.5
[10]	62.2	SRP in GCPW	32.2	32.2	Dual feed, 1 layer-PCB	11.8
[11]	26	SRP in SIGW	25.6	19.0	Single feed, 5 layers-PCB	11.53
[12]	35	FC in MSL	29.6	26.0	Single feed, 14 layers-LTCC	9.3
[14]	60	FC in SIW	6.6	6.8	Single feed, 2 layers-PCB	12.5
This work	28	UA in MSL	22.5	26.1	Single feed, 1 layer-PCB	11.3