Digital Mod. Power Level Accuracy Relative to CW

This test compares the digital modulation power level to the CW power level at the same frequency. If the UUT is not equipped with an internal digital baseband generator, then its external I/Q inputs are driven by an E443xB or E4438C. A power meter and power sensor are used to measure the UUT output power in CW mode and in digital-modulation mode. The difference between the two power levels is compared to the specifications.

The test is performed with two different modulation formats: QPSK and GMSK.

Required Test Equipment

Instrument	Critical Specifications for This Test	Recommended Model¹
Power Sensor	none	N8482A
Baseband Generator	Used when ESG doesn't have an internal BBG.	E4438C Opt [001 or 601] or [002 or 602]
Power Meter	none	N1914A²
Attenuator	none	8491B Opt 010

Refer to the main equipment list for alternate models..
Power meter N1914A with serial numbers ranging between MY00000000—MY53040007 require Service Note 07 to be applied for measurement repeatability. Please have this service note applied or verify it was applied before using this power meter. The affected service note is N1914A-07.

Connections and Setup Procedures

All test equipment requires a 30 minute warm-up period to ensure accurate performance.
In the following test setup, direct cable and adapter connections are designated as solid lines. Changeable cable and adapter connections are designated as dashed lines.
Connect all test equipment as shown.
Connect GPIB cables to all GPIB-controlled test equipment.
While performing this test, follow all instructions on the controller display.

Setup for DUT with an internal baseband generator

Setup for DUT without an internal baseband generator