
ARIB STD-T91
-26-
Table A3-4 Measurement parameters of a spectrum analyzer
Item Set
value
Resolution bandwidth (RBW)
1 MHz
Video bandwidth(VBW)
Auto
Sweep time (SWP)
1 s
Attenuation (ATT)
0 dB
Data points (Point)
1001
Detection (Detect)
RMS
Average count(Average)
100
Frequency span(SPAN)
10 MHz
Preamplifier (Pre AMP)
ON
(6) Estimation equations for unwanted emission intensity
The signal level M of AMP output observed by the spectrum analyzer is a combined
value of ATT input signal level (unwanted emission intensity)
, ATT thermal noise and
AMP thermal noise, and can be expressed in the Equation (1).
( )
1
1
1
1
L
G
kT
L
kT
L
M
a
⋅
⎭
⎬
⎫
⎩
⎨
⎧
+
⎟
⎠
⎞
⎜
⎝
⎛ −
+
=
α
M:
AMP output signal level
α
:
ATT input signal level (unwanted emission intensity)
L: ATT
attenuation
k: Boltzamann
constant
T
a
:
Ambient temperature (K)
T
1
:
Equivalent noise temperature (obtained by converting AMP noise into AMP
input.) (K)
G: AMP
gain
Here, T1 can be expressed as Equation (2).
( )
2
)
1
(
0
1
L
T
F
T
−
=
F:
AMP noise figure (antilog)
T
0
:
Temperature 290 K
Содержание 8494B
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