What difference between Connectivty_test and HCI black box FW?

[Annie_he]

Hi NXP,

   We are testing SRRC for kw45 bluetooth boards and it designed by us.

   When we test RF test, is accour different result by using different FW, connectivity_test and HCI black box. 

   like below:

   When test Frenquency range, signal send by LE_transmitter_cmd is lower than connectivty test cmd

send by LE_transmitter_cmd：01 1E 20 03 00 25 00, result=-36.953dBm/MHz:

send by connectivty test cmd："Mode TX, Rate BLE 1Mbps, Whiten Fixed, Channel 42, Power 31, Payload 37, XtalTrim 26> Mod PN", result=-39.23dBm/MHz:

     It is higher 2dB in connectivity test.  Why and how it can occured? and we use the same sounding only different FW.

    Here is we use:

     SDK example: KW45B14ZEVK 2.12.7

     FW: connectivity test / HCI black box from, which only I change is Xtaltrim=26.

     MXUXpresso IDE: V11.8.0_1165

   If you have any ideas about the commands and how to pass certification, please let us know, thanks.

   Best Regards,

   Annie

[Christine_Li]

Hi， @Annie_he 

Anything else I can do for you on this case?

Or do you have any other questions or queries?

Best regards,

Christine.

[Christine_Li]

Hi, @Annie_he 

I found our test result, it seems different with yours.

There is no these 2 little peak in our test results as shown in the below screen shot.

For details, you can also refer to our test report on KW45-EVK.

AN13228-KW45B41Z-EVK RF System Evaluation Report for Bluetooth Low Energy Applications

I have request our AE team help to test again, and at the same time, please share me your detailed test steps, so that we can compare and find whether have any different steps during test.

Best regards,

Christine.

[Annie_he]

Hi Christine_Li,

    Thanks for your attention in this post!

    But the report that you posted the picture, the power it set is 0 dBm and it is uppper bandege which signal is 2480MHz not 2400MHz. And I do not know the reason it set the minium power. But when we go to do the SRRC certification, we need set the max power 10 dBm. And SA setting is different from SRRC requested. SRRC request 

     Now we found to decrease the power to 9dBm-9.5dBm, we can pass 2M Freq Range in the certification, But there is a little margin, it is stiil dangerous for us. 

    Thank you again.

Best Regards,

Annie

[Christine_Li]

Hi, @Annie_he 

Thanks for your reply, and you are welcome, it is my job to support you.

I have forwarded your feedback to our internal team, our expertise will test today, hope they can share some good news or ideas to us.

Once have any updates, I will let you know.

Best regards,

Christine.

[Christine_Li]

Hi, @Annie_he 

Our internal team's test result is similar with you.

Please see below:

But after checked the AN13228, we found the BT limit is -20dBm, not -30dBm.

It means, according to the AN13228's BT limit, we can pass for sure.

Can you please help to confirm SRRC certification limit requirement?

If you have any specification files, can also share us to check together.

Best regards,

Christine.

[Annie_he]

hey Christine,

       We are not talking the same thing.We are testing Freq Range not Emission in Band. It is not a good solution for us.

       The specification files we are refering is as attach. I am sure the limit is 30dBm/KHz as below SRRC limit .

      It meas When we are sending signal in 2402MHz or 2480Mhz, It request power in 2400MHz&2483.5MHz need to less than -80dBm/Hz. And we need to calculate, Power dBm= -80dBm/hz+10*log(100000)= -80+50= -30dBm/KHz, So its limit should be -30dBm/KHz, it is talking clearly in ETSI EN 300 328 V1.7.1 (2006-10).pdf and SRRC number 129.

Our SA setting when we are testing Freq Range in 2400

Center Freq=2400MHz

Span=10MHz

RBW=100KHz

VBW=100KHz

Sweep time =60s

offset=cable loss+Antenna Gain

Detector=RMS

Max hold

You can try and talk to me.

Best Regards,

Annie

[Christine_Li]

Hi, @Annie_he 

Thanks for your reply.

Sure, I will forward your feedback to our internal team and request to continue to support this case.

Any updates I will let you know.

Best regards,

Christine.

[Christine_Li]

Hi, @Annie_he 

For the spec mentioned by you, we also have test result please see below pic:

And would you mind to speak Chinese for better understanding each other?

您是要测带外杂散信号吗? 可以将您的问题详细描述一下发到我的邮箱：christine.li@nxp.com

我把您原始的邮件转发给我们的内部专家团队帮忙看看，避免因translate引起误解。

Best regards，

Christine.

[Annie_he]

Hi Christine_Li,

     先简单在这里回复一下。我们测试KW45 SRRC报告遇到的问题是Ble 2M PHY-2400MHZ边带power过于接近limit的问题。

SRRC 129号中与2M PHY-2400MHz 2400相关的限值要求共两项:

1. 定义的使用频率范围为2400-2483.5MHz，规定使用频率上下限处的等效全向辐射功率不大于-80dBm/Hz。该测试也可理解为频率边缘测试。

公式换算即为： -80dBm/hz+10*log(100000)= -80+50= -30dBm/KHz。

2. 特殊频段杂散测试 2M PHY-2390-2400MHz，限值要求也为-30dBm。

我们参照的测试的规范和方法如下：

频率范围测试要求，参考文档：ETSI EN 300 328 V1.7.1 (2006-10)

频率范围测试要求以及测试方法，参考文档：蓝牙的射频指标及检测方法

我们的板子测试的结果如下：

FW烧录的是kw45b41zevk_connectivity_test_bm，SDK：2.12.7

测试时，频谱仪需补的Offset应为cable loss+Antenna Gain

1. 2M PHY 2400MHz 频率边带测试

KW45测试2M PHY频率边缘2400MHz结果为： -30.446dBm<-30dBm，余量仅为0.446dBm

KW45测试2M PHY频率边缘2400MHz结果为： -30.383dBm<-30dBm，余量仅为0.383dBm

我们目前2M PHY 2400MHz的边带都已经非常接近Limit -30dBm，测试KW45 EVK也有类似的情况，你们可以照Post里我贴的方法测试一下。目前发现调节RF matching不能很好的解决，降功率才能有比较好的效果。

所用到文档我上传到Attach里。

Best Regads，

Annie

[Christine_Li]

Hi, @Annie_he 

感谢提供的详细信息。

我们的内部AE团队同事最近有点忙，还没回复我，我会持续跟踪，有进展了会第一时间告知到您。

Best regards，

Christine.

[Christine_Li]

Hi， @Annie_he 

抱歉，这么久没有回复您，刚刚收到我们内部团队的回复，对于您的该项测试，我们还有一些疑问：

您主要测试两个参数，一个是带外发射功率，这个是测试的最大等效全向辐射功率，这个应该不是传导测试吧？

第二个测试的杂散信号应该是在中心频点2.5倍信道带宽以外，也就是2.4G+-50M？

SRRC认证：蓝牙及WI-FI产品型号核准检测的标准及具体要求！_四川成都第三方检测认证机构 (wanttest.com)

SRRC认证：蓝牙及WI-FI产品型号核准检测的标准及具体要求！

SRRC认证：蓝牙及WI-FI产品型号核准检测的标准及具体要求！《无线电发射设备型号核准证》，出厂设备的标牌上须标明型号核准代码。

您的测试文档也提到要在杂散域来测

麻烦帮忙回复一下以上疑问，感谢。

Best regards,

Christine.

[Christine_Li]

Hi, @Annie_he 

对于第1个问题，补充一下：您是不是测的是辐射方式？还是最大等效全向辐射功率？是传导测试吗？

对于第2个问题，再补充一下，如下图，请问您测试的是带外发射这个频段吗？还是杂散发射频段的？

因为我们看到您测试的是：

杂散域的话是在：2.5倍信道带宽以外

而您测试的是： 2M PHY：2390-2400MHz，结合下图看起来是在带外发射域而非杂散域？

所以麻烦您确认下。

Best regards,

Christine.

[Annie_he · Accepted solution]

Hi Christine,

1.为传导测试。为了等效成EIRP，最后计算是需要将频谱仪显示的数值+天线增益+占空比。这一点，在ESTI里面有讲，可以看看。

2.2390-2400MHz为特殊频段杂散，SRRC353里面第七点特殊频段杂散有规定RBW=100KHz, limit小于-30。

目前降power初有效果，这一问题我会先关掉，如果你们有更好的方法也可以联系我。感谢支持。

annie

Best Regards.

[Christine_Li]

Hi, @Annie_he 

感谢反馈并及时close该题。

这个问题比较典型，我们内部还要继续讨论一下，如果有更好的方法，会继续share给您的。

Best regards,

Christine.

[Christine_Li]

Hi, @Annie_he 

Do you have any chance to read my previous comment?

Please let me know whether you have any other queries.

Best regards,

Christine.

[Christine_Li]

Hi, @Annie_he 

Do you have any chance to read my previous comment?

Please let me know whether you have any other queries.

Best regards,

Christine.

[Christine_Li]

Hi, @Annie_he 

The test result of TX power in band is normal. And it complies with the BLE specification. 

Please let me know whether you have any other concerns on this case.

Best regards,

Christine.

[Annie_he]

Hi Christine_Li,

     KW45-EVK 2M-Freq Range test result is as below:

There is also less margin to the limit(-30dBm) in 2400Mhz.

And test way I got from ETSI EN 300 328 V1.7.1 (2006-10) as attach. We have tunned a RF matching and got similiar result as KW45-EVK in SRRC 2M Freq Range.

If you have better ideas about the test way or how to get better one, please talk to us, Thank you very much.

Best Regards,

Annie

[Christine_Li]

Hi, @Annie_he 

Thanks for creating case to us and hope you are doing well.

I will check it and reply to you once have any updates.

Have a nice weekend.

Best regards,

Christine.