Compact Design of Circularly Polarized Antenna with Vertical Slotted Ground for RFID Reader Application

Table 2

Performance of proposed and reference antennas.

Kinds of antenna	(MHz)	Peak directivity (dB)	Peak gain; (dBi)	Radiation efficiency; (%)	F/B; (dB)	BW1; (%)	BW2; (%)
Proposed antenna	842.5	4.1	3.8	92.8	15.0	12.1	2.5
Antenna 1	928.8	5.7	4.6	77.8	10.5	2.9	0.65
Antenna 2	1034.3	5.3	4.9	89.3	3.8	6.3	1.4
Antenna 3	1215.2	6.5	6.4	97.0	5.7	13	2.2

: centre frequency of BW2; F/B: front to back ratio; BW1: 10 dB return loss impedance bandwidth; BW2: 3 dB axial ratio CP bandwidth.