IWR1642BOOST: confuse about the Er to design GCPW and antenna use RO4835 LoPro

user5017110

Part Number: IWR1642BOOST

Hi experts:

I'm confusing about the width of the GCPW, it is different between the roggers calculator and your documentation. roggers calculator's result is 8.74mil, but in the documentation is 7.08mil. In the documentation Er is 3.66, another documentation is 3.48, but roggers calculator shows Er is 3.461 at 78.5GHz. If I use Er 3.66 to calculate the width of the GCPW is about 7.08mil.

I want to know if I selected the wrong parameter of roggers calculator or which Er is correct? Which Er should I use to creat antenna and GCPW simulation in HFSS?

The dielectric materials is RO4835 LoPro.

Best regards！

over 6 years ago

0 CHETHAN KUMAR Y.B. over 6 years ago

TI__Mastermind 25825 points

Hello,

Please refer to below E2E thread:
e2e.ti.com/.../738111

Dk value given in the stack-up is a notional value (Typically it's stated for a lower frequency), Dk value De-rates across frequency.

For Antenna simulations, it's best to use the Dk value given by Roggers calculator.

For Trace width/Air gap calculations we need to rely upon 3D EM geometry and solver than planar solver present in the Roggers calculator.
Geometry dimension shown in the table is arrived after 3D EM simulation.

Thanks and regards,
CHETHAN KUMAR Y.B.

0 user5017110 over 6 years ago in reply to CHETHAN KUMAR Y.B.

Prodigy 40 points

I have got it. Thank you very much!

sincerely,

Owen Li.

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IWR1642BOOST: confuse about the Er to design GCPW and antenna use RO4835 LoPro