Single-Fed Broadband CP Bidirectional Antenna with Double-Layer Diagonally Aligned Plates for Universal UHF-RFID Applications

Table 3

Comparison between previous studies and this current research.

References	Fractional bandwidth of |S11| (%)	Fractional bandwidth of AR (%)	Maximum gain (dBic)	Overall antenna dimension
[6]	51.36	48.80	4.20	0.405 λL ×  0.405 λL × 0.005 λL at 2023 MHz
[7]	15.25	15.59	6.80	0.347 λL × 0.361 λL × 0.002 λL at 860 MHz
[8]	47.03	23.14	3.41	0.247 λL × 0.247 λL × 0.002 λL at 618 MHz
[9]	99.34	8.3, 13.3	2.1, 4.4	0.317 λL × 0.190 λL × 0.006 λL at 1900 MHz
[10]	46.68	6.19	8.00	0.520 λL × 0.988 λL × 0.260 λL at 1560 MHz
[11]	9.48	2.84	11.10	1.309 λL × 1.625 λL × 1.155 λL at 2310 MHz
[12]	89.66	82.00	3.30	0.373 λL × 0.240 λL × 0.023 λL at 3200 MHz
[13]	55.65	42.44	4.29	0.267 λL × 0.267 λL × 0.004 λL at 716 MHz
[14]	98.72	84.10	9.60	0.843 λL × 0.843 λL × 0.101 λL at 3370 MHz
Proposed antenna	28.47	52.55	5.89	0.369 λL × 0.696 λL × 0.025 λL at 759 MHz