Giga-tronics 8003 - Accuracy

Introduction
Manual 20791, Rev. C, June 2001 1-9
1.3.2 Accuracy
1.3.2.1 Transmission Loss or Gain Measurements
Transmission loss or gain measurements are made relative to a 0 dB reference point established during
calibration. Therefore, frequency response errors of the source, sensors, and signal splitting device are
removed. The remaining elements of uncertainty are instrument linearity and zero set uncertainty, see
Figure 1-3, and mismatch error.
Transmission Accuracy = Instrument Accuracy + Mismatch Uncertainty
The low VSWR 8031XA series of sensors and the high power 8032XA series sensors have built-in
attenuators. Therefore, the linearity at a particular power level must be modified to apply to the
unattenuated sensor. Thus, for the 8031XA series which have a 6 dB attenuator, the linearity
specifications will be for 6 dB more power than in the basic 8030XA Series of sensors. This is reflected
in the scaling at the bottom of Figure 1-3.
Figure 1-3: Uncertainty Due to Instrument Linearity & Zero Set vs. Input Power
80301A
80310A
80320A
80330A
80501
Sensor
Bridge
Power (dBm)
Maximum Error (dB)
3
2
1
0
-1
-2
-3
20
26
30
10
16
20
0
6
10
15
-10
-4
0
5
-20
-14
-10
20
-5
-30
-24
-20
10
-15
-40
-34
-30
0
-25
-50
-44
-40
-10
-35
-60
-54
-50
-20
-45
70
-64
-60
-30
-55
CW Mode
AC ModeDC Mode
20