External Frequency Modulation Frequency Response

(E8663D Option HE3 and E8257N Only)

External Frequency Modulation Frequency Response verifies that a selected FM deviation remains constant within ± 3 dB as the FM rate is varied from 10 Hz to either 1 MHz or 5 MHz (depending on FM Path) and the DUT CW frequency is varied from 500 MHz to 1.0 GHz while a sinusoidal voltage is being supplied to an external input. If the DUT meets the frequency response specification in this CW frequency range, frequency response in all other frequency ranges will be assured.

For high β conditions (β=fdeviation/frate), the measurement is made by a signal analyzer in zero span by changing the tuned frequency and detecting when the peak input signal drops by 3 dB, indicating that the tuned frequency is beyond the maximum source frequency deviation. For low β conditions, the measurement is made by measuring the adjacent sideband amplitudes and calculating the deviation based on the predicted spectral distribution of a FM signal. All calculations of frequency response in terms of actual/expected frequency deviation are relative to a measurement made at the 1 kHz reference frequency deviation.

Required Test Equipment

Test Equipment

Recommended Models

Alternative Models

Spectrum Analyzer

N9030B Opt 5xx1

N9030A Opt 5xx1

E444xA2

Function Generator

33622A

33611A
33612A
33621A
33250A
33120A Opt 001

Digital Voltmeter

3458A Opt 002

34470A
  1. 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. An 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.
  2. 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.

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.

  1. Connect all test equipment as shown.

  2. Connect GPIB cables to all GPIB-controlled test equipment.

  3. While performing this performance test, follow all instructions on the controller display.

 

External Frequency Modulation Frequency Response Test Setup (External 1 Input)

 

 

External Frequency Modulation Frequency Response Test Setup (External 2 Input)

 

 

 

In Case of Difficulty

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

  1. Check the equipment setup (see above). If the setup is incorrect, make the necessary corrections and rerun the Performance Test.

  2. 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.

  3. If you cannot correct the problem using the troubleshooting procedures in the Service Guide, obtain service from Keysight Technologies. Refer to Contacting Keysight Technologies.