[Arm-netbook] HDMI High-Frequency Layout: Recommendations

Andrew Bolin fivepointpalmexplodingheart at gmail.com
Fri Aug 11 02:56:50 BST 2017

>> Also I'd personally not use curved wriggles. HF signals travel in a
>> straight direction. With curves they start diffracting and start
>> bouncing cross each other and might start to radiate or echo back.
> mmmmm.... *stress*!  anyone else feel the curves are "Bad"?

No. You've followed a bunch of very good advice about length matching,
impedance etc.
It looks like you've generally kept the pairs parallel through the curves,
which is great.

If you have an easy option in your software to switch from 45 degree
corners to smooth curves, I would do it - if there's not, don't worry.

>> If tight for space you can use 90% corners with a chamfered outer
>> edge. I suppose the chamfer acts like a mirror.

The chamfer is there for impedance reasons, it's not a mirror, and note
that a curve is preferred.
You also run the risk of manufacturing problems by doing the chamfer -
you're already at the minimum trace width, right?

As you've previously said, the old layout was further away from best
practices, and *it worked*.

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