Single antenna shared between BCM20736 and wifi SoC

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Anonymous
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Hi Sir,

We create a device that use the BCM20736 for BT and another SoC for Wifi.

We use an antenna switch to make BT and wifi share the same antenna.

The switch is controlled by the wifi SoC and the communication is UART between BT and wifi chip.

Is it workable? Do you have any suggestion when I switch the antenna back and forth?

Thanks.

Fran

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1 Solution
Anonymous
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My question is how fast your UART can do? Switch can be fast but if your SoC cannot handle the timing properly, it will introduce WiFi and BT loss the link. Whatever WiFi or BT, they will send out Beacon or Adv to maintain the link. If you cannot come back after next Beacon, you will loss the link. You may reduce 0.1USD for single PCB antenna but you may pay more than 1 USD for timing issue.

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MichaelF_56
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This is not supported here on the community.

The BCM2073XS SIP module supports an internal antenna.

While the SoC supports an external antenna, we are limited with regards to support for external antenna designs.

It probably makes sense to contact someone in your region regarding support for an external antenna design that leverages the same antenna/switch for the Wi-Fi and BT chip.

nsankar boont roychang

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Anonymous
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Sorry to make you misunderstood. My question is not the antenna design.

My question is focus on, if we use single antenna between BCM20736(not sip) share with another WiFi chip. Anything need to care on 'firmware/software' perspective of view?

The WiFi chip is not Broadcom's chip, I'm wondering if it's workable.

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Anonymous
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This is very difficult design. We did implement similar idea in our combo design, but we control them from very low physical level, inside of MAC. In your system, the biggest issue is how you sync both side timing. Please also consider the message delay between WiFi and BT, it may introduce lots timing issue.

Personally, I would suggest you to use two antenna. Or consider our combo solution.

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Anonymous
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Thanks for the information.

My idea now is:

Step1: Host SoC switch antenna to BTLE and collect the data.

Step2: Host SoC switch antenna to WiFi which act as client and send the data to our backend server.

The above is the only way for such hardware design I think.

Then the cons will be the system is not very efficient and the system scale would be very limited.

What do you think?

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Anonymous
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My question is how fast your UART can do? Switch can be fast but if your SoC cannot handle the timing properly, it will introduce WiFi and BT loss the link. Whatever WiFi or BT, they will send out Beacon or Adv to maintain the link. If you cannot come back after next Beacon, you will loss the link. You may reduce 0.1USD for single PCB antenna but you may pay more than 1 USD for timing issue.

Anonymous
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Thank you so much and these things are what I consider.

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