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is it arc routing required for all High speed signal?

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  • is it arc routing required for all High speed signal?

    Hi everyone,

    i could see in one of reference design. There is many arc routing in differential and single end traces. i can understood the arc routing for avoid reflection and match proper impedance for the purpose used. but i need to know which frequency range it required ?. if any other purpose . kindly advice.

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  • #2
    90 degree bends start to be problem > 10GHz according to Rick Hartley.
    So rounded traces compared to 45 degrees would be even higher.


    • #3
      i never used 90 degree bend. but i need which frequency required arc routing


      • #4
        Kabaleeswaran so you are way above 10GHz?
        If not, then there is no direct need to do rounded routing.


        • #5
          can you share correct answer. if possible


          • #6
            There is no "correct" answer.

            When it is wise to use it, you are designing a very high frequency design and there are already a lot of other aspects that have a much greater influence on the signals.
            You still may want to use it, because you think it looks fancy.
            Either way, IF you do, I hope you create a better layout than the one you showed as an example.


            • #7
              Then how can we decided to routing the high speed signals in arc routing or zig-zag routing ?? based on requirement. who will decide to guide these high speed signals to be route in arc , 45 or zig zag ??

              As you suggested above 10GHZ will go for arc routing right ?
              what about zig-zag or any angle routing.. is it based on frequency or based on SI Engineer advice ? or based on selection of Material ?
              Last edited by Kabaleeswaran; 07-25-2023, 11:53 PM.


              • #8
                What is "zig-zag routing"? Are you referring to length matching with accordeons?

                how can we decided to routing the high speed signals
                So what is high speed to you?

                1) What is stopping you from applying rounded routing?
                2) If you think that there are simple rules that state use rounded routing when ... there are no such rules.
                3) I would even go so far as to state that there is no reason to do so at all. Unless you are extremely high speed and high quality (think 50GHz oscilloscope), but then you know enough not to ask this question.
                4) SI simulation can help.

                Most of today’s digital-based products create a large amount of on-board RF harmonic “noise” (EMI). While this digital switching won’t usually bother the digital circuitry itself, that same harmonic energy from digital clocks, high-speed data buses, and especially on-board DC-DC switch-mode power supplies can easily create harmonic interference well into the 600 to 850 MHz cellular phone bands and even as high as 1575 MHz GPS/GNSS bands, causing receiver “desense” (reduced receiver sensitivity).


                • #9
                  What are the signals - high speed digital? RF?
                  What is the IC?

                  Please be specific when you post a question.