ADRV9029 matching circuit TX chain baluns

Hello,

The recommended Baluns used in transmission chain of the ADR9026 (declared in "ADRV9026-System-Development-User-Guide-UG-1727.pdf"  -- page 221 ) for frequency range 650 - 2800MHz are "Johanson 1720BL15A0100".

But in "ADRV9029_EVB_Schematic_MB_Match" the Balun used for transmission chain are: " 1720BL15B0050".

I was wondering having the same hardware nature, why there is this difference and which one we should implement in our design?

Thank you in advance,

Regards,

Sara

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  • 0
    •  Analog Employees 
    on May 19, 2021 8:41 AM

    Please follow the Balun used in "ADRV9029_EVB_Schematic_MB_Match".

  • Thank you very much.

    And one other question, I expected to see the same config over matching circuit for all the RXs and TXs and ORxs, but instead each pair has a different suggested components for its output matching circuit for the same frequency range. (ex. TX1 and TX4 are different from TX2 and TX3 and ...).

    Thank you in advance.

    Regards,

    Sara

  • +1
    •  Analog Employees 
    on May 19, 2021 10:47 AM in reply to sarahmd

    TX1 and TX4, TX2 and TX3, RX1 and RX4, RX2 and RX3, ORX1, ORX2 has different imprdance at BGA reference  plane of ADRV9025. Hence the matching is also different.

  • Dear Pvalavan,

    Thank you very much for the clarification.

    I have one more question regarding the layout, I don't know if it is the right section of the forum to ask it or not.

    In the defined layout of ADR9029 in the datasheet, the position of feedback1 and feedback2 seems to be inverted. Here I have 2 questions:

    Could be an error of datasheet?

    If not, for the sake of simplicity, is it possible to use ORx1 with TX2/RX2, and ORX2 with TX1/RX1? I mean has analog foreseen any internal configuration to let us do this form of inverting? 

    PS: The attached photos shows what I mean by inverted.

    Thank you very much in advance.

    Regards,

    Sara

  • +1
    •  Analog Employees 
    on May 21, 2021 10:51 AM in reply to sarahmd

    In the defined layout of ADR9029 in the datasheet, the position of feedback1 and feedback2 seems to be inverted. Here I have 2 questions:

    Could be an error of datasheet?

    The configuration mentioned in the datasheet is correct.

    If not, for the sake of simplicity, is it possible to use ORx1 with TX2/RX2, and ORX2 with TX1/RX1? I mean has analog foreseen any internal configuration to let us do this form of inverting? 

    If using TX1/ORX1 and TX2/ORX2, Please configure like this in software,

    If planning to use TX1/ORX2 and TX2/ORX1, Please configure like this in software,

  • Hello Pvalavan,

    Thank you for the clarification.

    one other question, since we're looking to select the right components values on our custom design for the matching network, cross-checking the components list on ADRV9026 System Development User Guide and comparing with HB_MATCHING schematic of the ADRV9029, we found this misalignment:
    L510/L570 should not be installed based on the user guide in HB while they are present with value of 33nH on HB_MATCHING schematic.
    Since it is a 33nH exactly as the MB (650-2800MHz) version we supposed it is just a schematic BOM error and that they should be DNI effectively.
    We would like to have a confirmation anyway.
    Here some screenshots about it:
    Thank you very much in advance.
    Regards,
    Sara
  • +1
    •  Analog Employees 
    on May 24, 2021 12:45 PM in reply to sarahmd

    Please follow the EVB schematic for your custom design.

    Please note the RF Macthing may need some tuning if Layout and stack up are changed in your custom board.

  • Hi,

    We are using ADRV9026 in our design for 4G basestation. we are refering the Evaluation board for MB design as we need to cover LTE band 1, 5, 41. so we are using the same Balun mentioned in the schematics.i have the below query,

    the RX and TX baluns are different in impedances it is 50 ohms/ 50ohms, the other is 50 ohms/ 100 ohms.

    tried to find in the datasheet but the "TX1 and TX4, TX2 and TX3, RX1 and RX4, RX2 and RX3, ORX1, ORX2 has different imprdance at BGA" is not mentioned. I could only find differential impedance of 100 ohms. probably i missed out if it was mentioned.

    could you pls share the EVM (error vector) details for MB design?

    We are observing 42dB at band 5 but at band 1 and band 41 we are observing 39dB. so kindly confirm the components used on the MB evaluation board is as per the BOM. what is the EVB at band 1, 5, 41?

    could you pls advice how do we improve the EVM as 44dB as per the evaluation board.

    specifically how to improve the EVM of band 1  and 41 . will the Balun make any difference?

    IS the PCB layout common for both HB and MB design?

    Regards,

    Sumathi

Reply
  • Hi,

    We are using ADRV9026 in our design for 4G basestation. we are refering the Evaluation board for MB design as we need to cover LTE band 1, 5, 41. so we are using the same Balun mentioned in the schematics.i have the below query,

    the RX and TX baluns are different in impedances it is 50 ohms/ 50ohms, the other is 50 ohms/ 100 ohms.

    tried to find in the datasheet but the "TX1 and TX4, TX2 and TX3, RX1 and RX4, RX2 and RX3, ORX1, ORX2 has different imprdance at BGA" is not mentioned. I could only find differential impedance of 100 ohms. probably i missed out if it was mentioned.

    could you pls share the EVM (error vector) details for MB design?

    We are observing 42dB at band 5 but at band 1 and band 41 we are observing 39dB. so kindly confirm the components used on the MB evaluation board is as per the BOM. what is the EVB at band 1, 5, 41?

    could you pls advice how do we improve the EVM as 44dB as per the evaluation board.

    specifically how to improve the EVM of band 1  and 41 . will the Balun make any difference?

    IS the PCB layout common for both HB and MB design?

    Regards,

    Sumathi

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