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IWR1443BOOST: What would happen if I take FR4 instead of RO4835 to make my board?

Meng Cheng
Intellectual 480 points
Part Number: IWR1443BOOST

Hi
  Since it would be very expensive to make a PCB with RO4835 material, I was considering to use FR4 instead. There would be some RF signal loss or performance degradation. I want to kown how much it would be affected. The requirment of detecting range in my application is very short, which would not exceed 100cm, so if the performance degradation is in functional margin, it would be still acceptable. I have to figure out this question because my application is cost-sensitive.

Best regards

  • 0
    TI__Mastermind 18500 points
    Hi Chris,

    FR4 substrates, even "high-speed" substrates like Isola FR408HR, with spread-glass weave and rolled copper still exhibit a cliff in frequency dependent loss and phase variation as you get past 10GHz or so. I haven't looked into it explicitly, but I would think that GCPW structures would see something similar and so would any antenna structures.

    TI has not studied pushing the limits of high-speed digital substrates for mmWave applications yet so I cannot provide any specifics.

    It is worth looking into for short-range applications, but I suggest consulting with Isola or other FR4 vendors to get their insight into the problem.

    Please let me know if that helps.

    Thank you,
    Randy
  • 0
    TI__Guru 50240 points
    Hi Cheng,

    Since it's been several weeks since we've heard from you I am going to close this thread. Feel free to open up a new one!


    Cheers,
    Akash