10
Practical Application Examples
Absolute output power measurements with
flatness correction
One benefit of the flatness-correction capability is
the ability to measure the absolute output power of
active devices. Since the input power level to the
DUT is kept constant, the magnitude offset feature
of the Agilent 8510 can be used to display absolute
output power across the entire frequency span of
the device. Table 6 shows the procedure for
absolute output power versus frequency measure-
ments with test port flatness correction.
Table 6. Absolute output power measurements with flatness correction
8510C Keystrokes Description
Set up the source and power meter as illustrated in Figure 2
Set up the measurement
PARAMETER [MENU] Set up the analyzer for a b
2
measurement.
{USER 2 b
2
}
Activate the test port power flatness-correction
Perform the flatness correction calibration. Set the test port power level and enable the flatness
correction as explained in Table 1.
Connect a thru
Perform a thru calibration with the flatness correction enabled
[CAL] Perform a thru calibration to eliminate the frequency response errors of the port 2 path in the measurement. Be sure to
{CAL#…} include any attenuators and/or adapters which are part of the measurement in the thru calibration. It may be necessary to
{CALIBRATE:RESPONSE} swap adapters for the thru connection. Any cal set may be selected to access the response calibration in the calibration
{THRU} menu structure
{DONE RESPONSE}
{CAL SET #}
Connect the DUT
Measure the absolute output power
RESPONSE [MENU] When the device is reconnected, the gain will be displayed. Enter a magnitude offset equivalent to the test port power level
{MORE} (P
2
). Measure the absolute output power at any point in the measurement span.
{MAGNITUDE OFFSET}
P
2
[x1]
