Hi Nick,

     I am not very clear with #2 and #6 questions. For other questions, please refer to following:

1. Yes, 17.5mm ground edge is OK.

3. Of cause, it shouldn't place components in the keep out area. And it shouldn't place high form factor metal components close to the antenna area. For the GND vias position, I think it is OK.

4. The normal GND via size is OK. But it is better to place the GND vias with a gap < 1/20 wave length.

5. The reference board is about 1.6mm thickness, but the thickness has no big impact to antenna performance.

Regards,

Jun

Hi Venkat,

     This problem seems not related to antenna or hardware side. Even if your antenna is detuned, the BLE signal will still be transmitted if you configure the radio properly.

     It recommends you to upload your source code for investigation from software team.

Regards,

Jun

Hi,

    There is no schematic for 915MHz till now. And this part is very old and will be EOL. I think you can contact your vendor for more information.

Regards,

Jun

Just power the module up, then it can works with the pre-flashed program.

The module can be soldered back with flashed program.

Thanks.

    当客户或FAE想要在Salesforce中创建一个硬件设计评审服务的案例时，他或她须检查以下能对无线SOC和模块进行彻底有效评审的预期事项，这是非常重要的。

• 提供产品用例的简短描述。

• 提交原理图评审的检查清单

  • 原理图应以可搜索的PDF格式提供，因为这将允许评审人在多张页面的原理图中搜索指定的网络或器件。

  • 最好提供整个设计原理图，但是，如果因保密要求而无法提供整个原理图，那就在案例说明中提供所用电源、主机MCU型号和其他无线器件型号（如有）的详细信息，以便彻底评审。例如，如果设计中有WiFi部分，而在提供的原理图中看不到，那么我们提供的评审反馈就不那么完整，因为在单个PCB上临近位置的多个无线电需要额外的软件和硬件更改来改善无线电之间的共存。

  • 在原理图中未提及的情况下，提供连接到EFR32的所有元器件的型号，因为元器件特性可能因尺寸不同而不同，就可能影响预期的性能，例如，由于匹配网络的失调而影响的射频性能。另外，请提供HFXO和LFXO（如有）晶体的规格书，因为晶体可能有多种变量，如果没有提供完整的型号，找到正确的规格书将会令人困惑。

  • 除了规格书的建议外，还应参考以下文件，并尽可能遵循原理图设计指导，以达到最佳性能。

    • 

    •  芯科实验室的相关器件参考板的原理图。选择参考设计中的满足规格书要求的元器件值。

• 提交PCB布局布线评审的检查清单

  • PCB布局布线应以Gerber文件格式提供所有层，包括焊接掩模、锡膏和钻孔文件。一般来说，Gerber文件是提供给PCB制造商的，因此重要的是评审最终设计文件，而不是CAD文件本身，以便检查可能导致制造或性能问题的任何异常。

  • 除了规格书建议外，还应参考以下文件，并尽可能遵循PCB布局布线指导，以实现最佳性能，尤其是射频性能。

    • AN928.1 for EFR32xG1x

    • AN928.2 for EFR32xG2x

    • 芯科实验室的相关器件参考板的PCB布局布线图

• 如果以前无线硬件团队在另外的案例入口中评审过相关的设计，则以以前的案例（案例中评审了相同的设计）为父案例来创建新的案例。为了便于追溯，将相似的案例关联在一起是很重要的。

Hi,

    一般2D pattern 按x,y,z方向有三个切面做发射扫描，然后再在这三个面内不同的转角上有不同的增益和天线效率，这样就形成了2D方向图。

谢谢！

Jun

Hi,

    Please keep the gap as big as possible between antenna and plastic case. It recommends to leave the gap over 3-5 mm.

Regards,

Jun

Hi, 

    Basically there is no problem with your calculation method. But the battery life is heavily related to your application.  The packet longth, data rate, output power, duty cycle, and sleep mode factors impact the battery life. I think you can get 1 year life base on these factors' appropriate configuration.

Regards,

Jun

Hi,

     The 2.4GHz Zigbee only supports DSSS-OQPSK modulation. When you configure the chip into Zigbee protocol, the modulation is set this modulation automatically.

Regards,

Jun

Hi Vegard,

     What's your performance difference requirements between 868MHz and 915MHz?  I think you can use each reference circuits for both band if the difference < 1dB. You can compare it if you have the demo boards. You can get refer to following application note for the reference circuits: https://www.silabs.com/documents/public/application-notes/AN648.pdf

Regards,

Jun