IWR6843ISK: Antenna pattern and matching parameters

Zhonghang Ji

Part Number: IWR6843ISK

Hi all,

I would like to redesign the antenna on IWR6843ISK board. Before I do that, I simulate the antenna (1by3, including the RF trace and matching network - shunt stub). However, the S11 is way off (even worse) from the threat posted before :

e2e.ti.com/.../749295

I would like to know if I'm using the wrong parameters, or there is a new version released. My parameters are listed below:

Software: HFSS. Geometry is imported from Altium Designer to HFSS. DK: 3.55. DF: 0.0037 (based on Rogers datasheet).

Thanks

over 5 years ago

0 CHETHAN KUMAR Y.B. over 5 years ago

TI__Mastermind 25835 points

Hello Zhonghang,

It would be very difficult to comment from these, Could you please post your simulation results and setup conditions port location, simulation conditions frequency used (62GHz is the center frequency) etc...

For the DK and DF please use from Rogers. DK values would be different for different frequency, Hence it would be best to take it from the below Rogers calculator.

https://www.globalcommhost.com/rogers/acs/techsupporthub/en/calculatorMWI.php

Also material stackup and it's property also contributing factor. Port location for the simulations are from at the edge of the package.

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Zhonghang Ji over 5 years ago in reply to CHETHAN KUMAR Y.B.

Prodigy 70 points

Hi Chethan,

Thanks for your reply. Please find my simulation results below:

0 CHETHAN KUMAR Y.B. over 5 years ago in reply to Zhonghang Ji

TI__Mastermind 25835 points

Hello Zhonghang,

Thank you for sharing the results, Please review the stack up information, thickness, metal thickness, also please check the DK values as per Rogers calculator shown from the above link at 62GHz frequency. DK value play major contribution, you could vary DK and see the sensitivity w.r.t. to S11.

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Zhonghang Ji over 5 years ago in reply to CHETHAN KUMAR Y.B.

Prodigy 70 points

Thanks Chethan.

I did check all the stack up info. All parameters are matching to the EVM board. Also, I player around the DK value, which only shift the frequency span left and right instead of up and down. Could you confirm that the link I shared with you before, which is showing the 1by3 antenna pattern?

Thanks a lot

Zhonghang

0 CHETHAN KUMAR Y.B. over 5 years ago in reply to Zhonghang Ji

TI__Mastermind 25835 points

Zhonghang,

Could you please re-share the link?

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Zhonghang Ji over 5 years ago in reply to CHETHAN KUMAR Y.B.

Prodigy 70 points

Here is the link below:

Thanks

Zhonghang

0 CHETHAN KUMAR Y.B. over 5 years ago in reply to Zhonghang Ji

TI__Mastermind 25835 points

Zhonghang,

Thank you, what do you want to confirm from this link?

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Zhonghang Ji over 5 years ago in reply to CHETHAN KUMAR Y.B.

Prodigy 70 points

Chethan,

I just want to confirm that the S11 plot is reflecting the 1by3 antenna matching, which is the same as the layout I provided before. Also, regarding to the S11 plot, can we still consider it's a 4 GHz bandwidth.

Thanks

Zhonghang

0 CHETHAN KUMAR Y.B. over 5 years ago in reply to Zhonghang Ji

TI__Mastermind 25835 points

Zhonghang,

Yes, S11 plot is for IWR6843ISK board which is three element series fed patch array. With S11 around -7dB to -7.5dB 4GHz bandwidth is achievable, But at S11 of -10dB level it's hard to achieve 4GHz bandwidth in the current stackup, But it may be reasonable trade-off at S11 of -7dB to have 4GHz bandwidth.

Thanks and regards,

CHETHAN KUMAR Y.B.

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IWR6843ISK: Antenna pattern and matching parameters