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SC1905 matching networks

Thread Summary

The user inquires about the missing matching networks for the SC1905 in the 1200-1800MHz frequency band. The final answer indicates that Analog Devices has no matching networks for this range and suggests using the SC1905-EVK1900 as a starting point, with provided component values from a similar but non-production SC1905-EVK900 design. The user is advised to fine-tune the values using a Vector Network Analyzer for optimal performance.
AI Generated Content
Category: Hardware
Product Number: SC1905

Hi,

I am going to use SC1905 in the frequency band 1200-1800MHz. Unfortunately the schematic for this band is missing from the HW design package. Would you please provide the matching networks of the RFOUTP/N. RFINP/N, RFFBP/N ports?

Thank you very much!

  • Hi,

    I checked the history and we have never developed an EVKIT to support this frequency range, even for the SC1894 EVKs.  We don't have the matching networks for this range and don't have the resources to determine them.  I think your only option is to determine the best values yourself empirically by swapping out matching circuit components on an SC1905-EVK1900 since that is the closest supported frequency band to your target range.  There is one potentially useful piece of information I can provide.  Several years ago, there was an exercise done by an apps engineer (no longer around) to determine the matching components for a SC1905-EVK900.  He completed the work, but the board never went into production.  I have provided the components values he came up with in the table below.  The optimal values for your application are likely somewhere in the middle between the EVK900 and EVK1900.  That could be a good starting point, then use a Vector Network Analyzer to fine tune them for maximum return loss.

    Designator Comment Description Quantity Manufacturer 1 Manufacturer
    Part Number 1
    Part Substitution
    Allowed?
    C52 NO LOAD -- -- -- -- --
    C17 2.0pF 2.0pF 0402 1 Murata GJM1555C1H2R0BB01 Yes
    C18 2.2pF 2.2pF 0402 1 Murata GJM1555C1H2R2BB01 Yes
    C20 1.0pF 1.0pF 0402 1 Murata GJM1555C1H1R0BB01 Yes
    C21, C53 0.2pF 0.2pF 0402 2 Murata GJM1555C1HR20BB01 Yes
    C23 0.7pF 0.7pF 0402 1 Murata GJM1555C1HR70BB01 Yes
    DC1 10dB Coupler Anaren 700 - 1000 MHz 0805 10dB Coupler 1 Anaren DC0710J5010AHF No
    L2, L3, L8, L9, L10, L11 22nH 22nH 6 Murata LQW15AN22NH00 Yes
    L5, L6, L12, L13, L14, L15 10nH 10nH 6 Murata LQW15AN10NH00 Yes
    T1, T2 BAL 50 - 100 Anaren 800 - 1000 MHz 50Ohm
    UnBal - 100 Dif Balun
    2 Anaren BD0810J50100A00 No
    T3 BAL 50 - 200 Anaren 800 - 1000 MHz 50Ohm
    UnBal - 200 Dif Balun
    1 Anaren BD0810J50200A00 No