Other Parts Discussed in Thread: WL1835MOD, WL1831, LAUNCHXL-CC3235SF, UNIFLASH
I am hardware design engineer from China and I am involved in certification phase of our new device, which is using CC3235MODASF as the 2.4GHz&5GHz WiFi module works in STA mode.
Past week we have been performing Radiated electromagnetic filed immunity test (RS) according to test standard EN61000-4-3, criterion A in a certified facility. During the test the DUT is exposed to electromagnetic field of 3V/m from 80MHz until 6000MHz. We are monitoring CC3235 WiFi by pinging it once per second from PC(the PC connected to the access point through wired and PC located out of EMC chamber, the CC3235 connected to the AP wirelessly). The CC3235 operates as expected from 80MHz until 3000MHz. From 3.0GHz until 6.0GHz the ping messages always or frequently lost. When the Radiated disturbance is turned off, WiFi start to operate normally immediatly or after few seconds. However, this ping lost is only observed during 3.0GHz to 6.0GHz in 2.4G WiFi mode, for 5G WiFi mode, it works normally.
After searching on the TI E2E community, I find a very interesting topic in the Link: WL1831MOD: Radiated electromagnetic field immunity test (RS) EN61000-4-3 FAIL - Wi-Fi forum - Wi-Fi - TI E2E support forums
The problem they faced was quite similar with me. The main reason they worked out is: WiFi module stops replying ping messages because of too high noise floor level on WiFi frequencies. At the lab which they are performing test, the lab use one amplifier in 1GHz-3GHz region and another one from 3GHz and 6GHz. It turns out that noise floor level at 2.4GHz is 10dBm higher when second amplifier operates, compared to when first amplifier operates. Thus WL1831 does not work in the 3GHz to 6GHz region. After they lower BG2 RX loss in PerSubBandRxTraceLoss (the loss of the rx path) for 3dB, WL1831 started to transmit between 3GHz and 6GHz. Finally they identified that the WL1835MOD_C2PC.INI file they used in the test was not correct, which lead to this issue.
Could you please help to check whether there is same parameter in CC3235MODASF can be configured? Maybe we can modify this parameter to check whether Radiated Immunity performance can be improved.
On the other hand, please direct us how to check whether this parameter is correct in our design? So we can avoid failure with the same reason as them.
We have struggled on this problem for several months, hope you can provide fully support. Many thanks.