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ADF4155 IBS Characteristics


I have a couple of questions from the customer. He is using ADF4155 Evalation board.

1. Fig.9 shows the IBS characteristics of ADF4155.   He wants to know the more detailed conditions about Fig.9.
    Is it possible to let me know the more detailed conditions like Fig.34  and other conditions ?

2. He wants to know the characteristics of IBS over temperature.   Do the characteristics of IBS get worse

    over temperature ?   If it is true, can the bleed current compensate it ?

    And let me know any other informations.

IBS is "Integer Boundary Spurs".

Best Regards

  • Hello ,

    This wide band sweep was performed using the ADF4350 as the VCO and a REFIN = 122.88MHz. I don't have details on the schematic other than that we would have used the ADF4350 evaluation board configured in VCO mode and used a dedicated separate board for the ADF4155.

    The VCO output is significantly better for spurs than the RFOUTs for the ADF4155, we state in the data sheet for best spurious performance, the VCO output should be used.

    Changing bleed current and temperature does not have any significant effect,