A Novel Concentric Annular-Ring Slot Dual-Band Circularly Polarized Microstrip Antenna

Table 2

Comparisons between the proposed antenna and other dual-band circularly polarized microstrip slot antennas.

References	Overall size (mm)	Impedance matching bandwidth	AR bandwidth	Gain (dBic)	Radiation efficiency
[9]		2.7%/1%	9.6%/4%	−1.9/−6.9	—
[10]		26.7%/11.3%	6.1%/6.0%	5.2/6.3	—
[11]		106%	32%/5.6%	3.81/3.44	—
[12, 13]		8.6%/15.5%	15.7%/15.5%	4.3/3.0	—
[14]		25.8%/47%	4.3%/3.6%	3.3/4.5	—
This work		14%/10%	1.23%/1.15%	7.3/6	88.7%/79.2%