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EV-ADF4401ASD2Z Evaluation Board's output is off frequency in Translation Loop mode

Hi Community,

I am evaluating the EV-ADF4401ASD2Z Evaluation Board and seemingly can't get the RF output to stay at the desired frequency in Translation Loop Mode. In Calibration mode the output is exactly on the target. 

The settings:

  1. Calibration Ref - 10 MHz / +9 dBm.
  2. External Reference - 10 MHz / +9 dBm
  3. External LO - 4.5 GHz / 0 dBm
  4. Windows 10, 64-bit OS

The software controlling the board is ACE v. 1.24.3095.1398.

The output signal in Translation Loop Mode sits at about 4.28 GHz vs 4.51 GHz in Calibration Mode.

Power supply is 6 VDC / 800 mA  from a benchtop U8002A by Keysight.

If anyone could reply with suggestions, I'd greatly appreciate it.

Thank you.

90125



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[edited by: ggall at 3:29 PM (GMT -5) on 19 Nov 2021]
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  • The IF output of ADF4401A is spec'ed from 50 MHz to 1 GHz, so external reference should be 50 MHz minimum. It may be a bug in the ACE software that allows IF to be configured to a lower frequency.

    Also, external reference input power of +9dBm looks too high. HMC3716 is spec'ed for max input power of +5 dBm. For calibration reference, 0 dBm input power is recommended.

  • Ggall,

    The 50 MHz external reference sine wave signal appears to be doing the trick.

    Thanks for pointing this out.

    The HMC3716 accepts 10 MHz, but only as a square wave.

    Kind regards,

    90125

  • I'm glad you were able to get this working.

    HMC3716 will accept a 10 MHz square wave signal, but due to filtering on the ADF4401A's IF path, the IFoutput will be severely attenuated at 10 MHz. The external reference and IF signals must match in frequency.

    For best jitter performance, it is recommended to use a higher IF frequency. See figure 18 on page 11 of the ADF4401A datasheet. IF signals between 100 MHz and 700 MHz give the best jitter performance, although this will also depend on the quality of your LO and external reference sources.

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  • I'm glad you were able to get this working.

    HMC3716 will accept a 10 MHz square wave signal, but due to filtering on the ADF4401A's IF path, the IFoutput will be severely attenuated at 10 MHz. The external reference and IF signals must match in frequency.

    For best jitter performance, it is recommended to use a higher IF frequency. See figure 18 on page 11 of the ADF4401A datasheet. IF signals between 100 MHz and 700 MHz give the best jitter performance, although this will also depend on the quality of your LO and external reference sources.

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