10j
75 1 4 3 5 1 2 19.093??89.86j
75 1 6 2 9 1 2 21.345??154.42j
76 1 3.5 3 4 1 2 19.52??79.33j
76 1 4.5 3 4 1 2 20.5??102.92j
76 1 6 2 9 1 1 22.732??162.33j
76 1 6 3 9 1 1 22??148j
78 1 6 4 7 1 1 17.8??101.83j
78 1 6 3 7 1 1 18.312??114.70j
78 1 6 2 7 1 1 18.95??128.34j
78 1 6 5 7 1 1 17.32??89.35j
79 1 6 6 9 1 1 18.054??90.814j
79 1 6 5 9 1 1 23.929??141.78j
79 1 6 2 6 2 1 19.37??138.00j
81 1 6 5 7 1 1 26.65??152.32j
81 1 6 6 7 1 1 19.433??98.55j
TABLE 4.9
Tag Bow-Tie Antenna Con?¬?gurations
Antenna
Name
hb
(mm)
lw
(mm)
iw
(mm)
ic
(mm)
g
(mm)
fy
(mm)
fx
(mm)
Input
Impedance
(V)
BowAS 72 1 7 2 8 2 2 18.97??141.61j
BowS 74 1 6 2 9 1 2 20.35??146.10j
Far-Field Tag Antenna Design Methodology 87
FIGURE 4.26
Bow-tie antenna design, BowS.
z
y x
FIGURE 4.27
Bow-tie antenna design, BowAS.
z
y x
0
20
40
60
80
100
120
140
160
180
850 860 870 880 890 900 910 920 930 940 950
0
5
10
15
20
25
Reactance
Real impedance
Frequency (MHz)
Real impedance ()
Reactance ()
FIGURE 4.28
BowAS impedance variation over a frequency range of 850??“950 MHz obtained from simulated results.
88 RFID Handbook: Applications, Technology, Security, and Privacy
Figure 4.30 shows the radiation pattern of the bow-tie antenna. As expected, the radiation
pattern con?¬?rms that the antenna behaves similarly to an electric dipole.
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