Analysis and Design of Gap-Coupled Annular Ring Microstrip Antenna
Table 2
Peak value of input impedance,
resonance frequency for upper and lower band for different feed locations.
Gap length
S = 0.095 cm
S = 0.100 cm
S = 0.110 cm
Feed point
(ohms)
(ohms)
(GHz)
(GHz)
(ohms)
(ohms)
(GHz)
(GHz)
(ohms)
(ohms)
(GHz)
(GHz)
c = 3.001 cm
39.40
74.08
1.727
1.899
43.58
73.93
1.744
1.899
53.05
73.30
1.778
1.900
c = 3.101 cm
37.55
72.15
1.754
1.934
43.62
72.06
1.771
1.934
55.90
71.75
1.806
1.934
c = 3.201 cm
36.50
65.02
1.788
1.977
42.35
64.16
1.806
1.977
53.20
65.50
1.842
1.977
*
: The peak value of input impedance for lower band. **: The peak value of input impedance for lower band. #: The resonance frequency for lower band. ##: The resonance frequency for upper band.