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 b2 measurement.
{USER 2 b2}

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}	(P2). Measure the absolute output power at any point in the measurement span.
{MAGNITUDE OFFSET}
P2 [x1]