Environmental Engineering Reference
In-Depth Information
Fig. 6.4
Antenna mea-
surements performed in
anechoic chamber [5]
Ta b l e 6 . 1
rmse
values, over the 810-960 MHz frequency range, between
|
S
11
(
f
)
|
measured
(for different acquisition windows) through the TD/FD combined approach and
|
S
11
,
ref
(
f
)
|
T
w
rmse
(ns)
100
0.040
50
0.037
40
0.019
35
0.019
32
0.010
20
0.021
10
0.068
6.4.1.1
Lower Limit for the Acquisition Time Window
As can be seen from Fig. 6.5(a) and Fig. 6.5(b), the
S
11
(
curve corresponding to
a 10 ns-long time window is far from representing the actual antenna behavior. This
result can be easily explained considering that according to (6.1), the frequency res-
olution corresponding to
T
w
f
)
=
10 ns is approximately 100 MHz, which is not even
adequate to resolve the two closely-spaced resonant frequencies that characterize
the AUT. In fact, looking at the specifications, it is known (and it is confirmed by
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