IWR6843: Using Custom/External Antenna with IWR6843ISK

Van, 

This sounds like a really interesting project. 

I think the first concern I have is in the selection of SMPM & SMA connectors. Standard SMA connections top out at 18 GHz and extended range SMA tops out at 26.5 GHz. While SMPM tops out at 67 GHz, we would recomend opting for a standardized connector where the maximum carried freuqnecy (and cutoff) is far above max carried frequency. I'd recomend looking at high quality 1 mm connectors. If you are intent on using SMPM and SMA connectors, then I'd strongly advise you to use a VNA to observe the s-parameters across 55 GHz - 66 GHz to not only characterize the connection but to also understand the potential signal fall out.

Next, unfortunately none of our EVMs support replacement of the patch arrays with an external launch/connector. Typically you would have matching elements and a tapering of the GCPW as it approaches the pin of the launch. Simply cutting a trace and inserting the external connector would invariably lead to poor matching and performance and if the S11 is poor enough could lead to damage of the radar. 

Your best bet will be to design a new PCB that uses either RO3003 (best performance) or FR408HR (mid performance) substrate for the antenna layers. More information on that can be found in our design guides. You would then be able to design a propper GCPW with transitions to your connector. Using HFSS or CST you could improve the match of the GCPW and connector to improve results when you fabricate. 

Finally, the MMWAVEICEBOOST will be invaluable in retrieving raw data for use not only in testing performance but also in gathering raw data for use in DSP development. 

I hope this helps and feel free to follow up with more questions. 

Thanks! 

Blake

Hi Blake,

Thank you for your detailed and helpful response regrading to the connector selection and the limitations when modifying directly on the EVM. 
We understand that cutting traces on the existing IWR6843ISK EVM is not advisable. Therefore, we plan to design a dedicated antenna PCB using RO3003 (followed your suggestion) as the substrate. Our design goals include:

- Implementing a controlled-impedance GCPW layout with a smooth transition to a high-quality 1.0 mm connector for operation at 60 GHz.

- Using simulation tools (Ansys HFSS) to optimize the matching and minimize reflections at the connector transition.

Could you kindly advise on the following details

- Are there any recommended layout guidelines or reference designs from TI that specifically illustrate the GCPW design and connector transition for mmWave applications

- For interfacing our custom antenna board with the MMWAVEICBOOST, do you have any insights on the best practices for mechanically and electrically connecting a separately fabricated PCB to the MMWAVEICBOOST board.

- Additionally, if there are any application notes or further documentation on connector selection and integration for 60 GHz systems, we would greatly appreciate your guidance.

Thanks a lot for spending time checking our issues.

Best Regards,

Phuoc Dang

Phuoc, 

Since you are designing your own board, i would recomend using the LVDS connections to enable raw data capture using the DCA1000 and thus bypass the MMWAVEICBOOST. The DCA1000 will come with a SAMTEC cable that you can use to connect if you go this route. You can also reference any of our EVMs layouts to see how to do this. The design files for each EVM are availible on that EVM's ti.com page. 

I will include some information on GCPW design below. However, we don't have any examples for the launch connection transitions since this varies by manufacturer. The manufacturer of your 1 mm connectors should have design recomendations. 

Here are some resources that will be invaluable. 

https://www.ti.com/lit/an/spracg5/spracg5.pdf 

https://www.ti.com/lit/zip/swrr161 

I hope this helps! 

Blake

Hi Blake,

Thank you very much for your support!

I will gather the given information and discuss with my team.

Thanks a lot for spending time checking our issues.

Best Regards,

Phuoc Dang

Thanks! Closing this thread.