IWR1443： I want to know the Dk of RO4835 Lopro in 77GHz,thank you.

Hello,

   You could refer from the below E2E Post, For most accurate Dk value please use the Rogers Calculators from their website.

https://e2e.ti.com/support/sensors/f/1023/p/738111/2743793?tisearch=e2e-sitesearch&keymatch=rogers%20calculator#2743793

Thanks and regards,

CHETHAN KUMAR Y.B.

user6449949,

Could you please post what results are different and what parameter you are comparing in data sheet.

Thanks and regards,

CHETHAN KUMAR Y.B.

CHETHAN KUMAR Y.B.

The Gain in 90deg of Phi, my result can't reach 10dB,there is only 2dB at 81GHz.When I use the Dk with 3.25,the gain can up to 10dB but the S11 is wrong,the frequence bandwide up to 79-88GHz

Thanks and regards.

I want to send my design file,but there seems to be some problems here,the send failed.

 Hello user6449949,

    You need to post the stack up and simulation setup condition/Plots from the simulation results to comment further on this. 

Is the stackup is different from that of IWR1443BOOST EVM?

Thanks and regards,

CHETHAN KUMAR Y.B.

 Hello CHETHAN KUMAR Y.B.,

I simulated the PCB antenna of IWR1443BOOST. I want to send my design file,but there seems to be some problems here,the send failed.I put the question here（www.researchgate.net/.../How_to_get_the_right_result_of_iwr1443）, can you please go to the website and have a look?

I'm trying to make my design exactly the same as the datasheet.

Thanks and regards.

Hello,

    Link above is not accessible. Could you please post the images of stackup used and setup conditions? 

Thanks and regards,

CHETHAN KUMAR Y.B.

www.researchgate.net/.../How_to_get_the_right_result_of_iwr1443

Hello,

I send the link once again.Could you open it?

Thanks and regards.

It's ok to send files.Could you see them?

Hello Lili,

   Is the stack-up and it's parameters used same? 

Thanks and regards,

CHETHAN KUMAR Y.B.

Hello CHETHAN KUMAR Y.B.,

  Yes, I used all paramenters which I measured. And add the substrate from 4mil to 4.7mil cause the Lopro,used the Dk with 3.46.

Thanks and regards,

Lili

Hello Lili,

     You cannot change the stack-up thickness of the RO4835LOPRO material generally, This is a core material (not a pre-preg material) which comes with 4mil thick with Cu cladding on both sides. And Cu thickness of ~0.05mm after plating on finished PCB. Use the dielectric constant as specified in the Rogers impedance calculator. Hence stackup details plays very important role.

Also simulation should use GCPW transmission lines structures along with antenna, And port location should be at the edge of the package where GCPW transmission lines starts. 50Ohm reference plane starts there. Simulation should also contain and transmitter and receiver antennas together. There will be coupling effect between Tx and Rx antennas that need to be comprehended. 

Thanks and regards,

CHETHAN KUMAR Y.B.

Hello CHETHAN KUMAR Y.B.,

I read the offic web of Rogerse and they say that the thickness need add 0.7mil when simulate, because of the lopro.The Dk is get from there https://e2e.ti.com/support/sensors/f/1023/p/738111/2743793?tisearch=e2e-sitesearch&keymatch=rogers%20calculator#2743793 which you show me before.

Do I need to draw all of these when I simulate?Include these metal hole? Does the 50Ohm reference plane starts from port A?

Thanks and regards,

Lili

Hello CHETHAN KUMAR Y.B.,

 If I could get the simulation file?

Thanks and regards,

Lili

Lili,

   Yes you need to include all the via metal structures, as it is in the EVM.

50 ohm reference plane starts at the edge o the package not at the ball, roughly 2mm after the ball. You need to assign port over there.

Thanks and regards,

CHETHAN KUMAR Y.B.

Hello CHETHAN KUMAR Y.B.,

Do you have the simulation files?  Can I get one to do some reserach?

Thanks and regards,

Lili

Lili,

    Unfortunately, simulation files are used only for EVM development, Cannot be shared. 

Thanks and regards,

CHETHAN KUMAR Y.B.