Internal FM Frequency Response

(E8257D/E8267D/E8663D Option UNT without H5K Only)

Internal FM Frequency Response verifies that a selected FM deviation remains constant within ± 1 dB as the FM rate is varied from 80 Hz to 100 kHz and the DUT CW frequency is varied from 500 MHz to 1.0 GHz. If the DUT meets the frequency response specification in this CW frequency range, frequency response in all other frequency ranges will be assured.

FM deviation is set to 100 kHz at an FM rate of 1 kHz. The actual deviation is measured with a measuring receiver and stored as the reference deviation. While the deviation setting remains at 100 kHz, actual deviation is measured for FM rates between 80 Hz and 100 kHz. If the measured deviation at any test rate is more than 1 dB different from the reference deviation at 1 kHz, the test fails.

Equipment Setups

This test supports two equipment setups using either a spectrum analyzer or a measuring receiver. The spectrum analyzer is the preferred solution.

Preferred solution

A spectrum analyzer with analog demodulation measurement application is used to demodulate the signal and measure the deviation.

Test Equipment

Recommended Models

Alternative Models

Spectrum Analyzer

N9030B Opt 5xx1, N9063EM0E Analog Demodulation Measurement application

N9030A2 Opt 5xx1, N9063EM0E Analog Demodulation Measurement application

E444xA3 Opt 233 Measuring Receiver Personality

Select any option of PXA spectrum analyzer (503, 508, 513, 526, 543, 544, 550) that has a maximum frequency greater than or equal to the maximum frequency of the unit under test. The N9030A/B Option 550 is required for units with Option 567. The N9030A/B Option 550 frequency range is adequate for all PSG-D frequency configurations.
To use the PXA N9030A with N9063EM0E Analog Demodulation Measurement application functionality above 3.5 GHz or for modulation rates above 50 kHz, the N9030A must be upgraded with either Option MTU or TES. Refer to the section in the Required Test Equipment topic.
Select any model of PSA spectrum analyzer (E4440A, E4443A,E4445A, E4446A, E4447A, E4448A) that has a maximum frequency greater than or equal to the maximum frequency of the unit under test. An E4448A is required for units with Option 567. The E4448A frequency range is adequate for all PSG-D frequency configurations.

Alternate solution

Alternatively, an 8902A measuring receiver is used to demodulate the signal and measure the deviation.

Test Equipment	Recommended Models
Measuring Receiver	8902A

Connections and Setup Procedures

All test equipment requires a 30 minute warmup period to ensure accurate performance.
In the following test setup, cables are designated as solid lines and direct connections are designated as dashed lines.
This performance test has a smart connection feature.

Connect all test equipment as shown.
Connect GPIB cables to all GPIB-controlled test equipment.
While performing this performance test, follow all instructions on the controller display.

Spectrum Analyzer Setup

Internal FM Frequency Response Test Setup

Measuring Receiver Setup

Setup for Measuring Receiver Calibration

Setup for FM Frequency Response Test

In Case of Difficulty

If this performance test fails, perform the following steps in order:

Check the equipment setup (see above). If the setup is incorrect, make the necessary corrections and rerun the Performance Test.
If this test fails with the equipment set up properly, refer to the troubleshooting section of the signal generator's service guide. If you do not have a printed copy of the service guide (Option OBW), one is available either on the CD-ROM that came with your signal generator shipment or on the Keysight Website.
If you cannot correct the problem using the troubleshooting procedures in the Service Guide, obtain service from Keysight Technologies. Refer to Contacting Keysight Technologies.