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‹ Experiment 2:
To tune down the center frequency (to 2.5GHz) of 2500AT43A0100
soldered on the initial land pattern by matching circuits.
‹ Experiment 1:
To shift up /down the center frequency of 2500AT43A0100 by
changing the land pattern with no matching circuits (Fo @ 2.65GHz)
Abstract
f
e
d
c
g
h
i
j
j
i
h
g
c
d
e
f
GND
Land pattern 1
(S22)
j
i
h
g
c
d
e
f
GND
Isolated
GND
Land pattern 2
(S33)
Initial Land PatternÆ Pins 4 & 5 isolated.
Land pattern 1Æ Connect pins 4 & 5 with GND
Land pattern 2Æ Antenna pins 3 & 6 connected together and
isolated from GND, pins 4 & 5 isolated as
GND
well
Isolated
GND
Initial land pattern
(S11)
Experiment 1: Land Pattern Comparison
-30
2.0
-25
-20
-15
-10
-5
0
2.2
2.4
freq, GHz
2.6
m1
m2
m3
2.8
3.0
m1
freq= 2.650GHz
dB(S(1,1))=-25.234
m2
freq= 2.605GHz
dB(S(2,2))=-18.205
m3
freq= 2.710GHz
dB(S(3,3))=-26.905
Experiment 1: Measured Result
Initial land pattern(S11)ÆCenter frequency is 2.65GHz
Land pattern 1(S22)ÆCenter frequency is shift down 50MHz to 2.6GHz
Land pattern 2(S33) Æ Center frequency shift up 60MHz to 2.71GHz
dB(S(3,3))
dB(S(2,2))
dB(S(1,1))
f
e
d
c
g
h
i
j
GND
Initial land pattern
Experiment2: Land Pattern Image
Matching
circuits (next
page)
0.5pF
-50
-40
-30
-20
2.0
2.2
2.6
freq, GHz
2.4
m2
m1
2.8
3.0
m1
freq=2.650GHz
dB(S(1,1))=-25.234
m2
freq=2.500GHz
dB(S(2,2))=-42.777
2500AT43A0100 without matching circuits(S11)ÆCenter frequency is 2.65GHz
2500AT43A0100 with matching circuits(S22)ÆCenter frequency shift down to 2.5GHz
Proposed matching circuits
0.5pF
4.7nH
-10
0
2500AT43A0100 soldered on initial land pattern
Experiment2: Return Loss & Matching circuits
dB(S(2,2))
dB(S(1,1))
Peak
-1.39
-8.67
-1.12
XY-plane
H cut
V cut
Total
-5.11
-14.03
-5.82
Avg.
Total
V cut
H cut
XZ-plane
-1.63
-3.95
-2.50
Peak
-4.47
-9.52
-6.97
Avg.
Total
V cut
H cut
YZ-plane
0.56
-1.46
-3.43
Peak
Experiment2: Radiation Pattern @ 2.5GHz
-2.17
-3.27
-9.03
Avg.
‹ Experiment 1:
The results show that the center frequency can be shifted
up/down by about 50MHz by changing the antenna land
pattern.
‹ Experiment2:
The center frequency can also be shifted down to 2.5GHz by
the matching circuit (shown as the page5).
Note: Combining experiments 1 & 2 can give the designer the
desired Fo
Summary
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