ESP32 WROVER-B Radiated Immunity problems

[Grant.Bradley]

We are currently undergoing EMC testing with our product and at the moment we are failing Radiated Immunity testing. This test is reference to EN 301 489-1. The reference is 9.2 Radio Frequency Electromagnetic Field (80 MHz to 6000 MHz) (EN 61000-4-3)

We are using test level 3 (10V/m). We are using the WROVER-B with PCB antenna.

During the test in the EMC lab it scans through the frequency range and when it gets to 609 MHz and 812 MHz the WROVER looses connection. We used a back to back horn antenna assembly to remove the remote access point (Dell laptop) from the chamber to ensure this was not being subjected to the field.

Has anyone else had issues or else been succesful with Radiated immunity tests?

We have now also been able to replicate this situation on the bench (i.e. not in the EMC lab) although it is uncontrolled (i.e. not calibrated in any way) but allows us to try and debug the situation.
We use a signal generator with an antenna attached to its output and set it to 609 MHz and 812 MHz and we can see the same result - the WROVER-B looses connection. (you cannot ping it) When the signal generator is switched off the WROVER will reconnect. The test criterion is A (it should keep the connection) Using a near field probe the WROVER-B only seems to loose connection when the probe is near the PCB antenna, probing elsewhere on the PCB, and on the other inputs and on the power supply is fine.

[ESP_Alvin]

Hi, Grant.Bradley

Enclosed please find the measurement report of WROVER-B in this test. When we are going under certification, we used test level 2 (3V/m), however you used test level 3 (10V/m), and currently we don't have test data for level 3, and in the specification it doesn't specify which level is mandatory for the testing, could you help switch to test level 2 and do some testing, and get feedbacks to us?

Thanks.

Alvin
Best Regards

[Grant.Bradley]

Thanks for your reply.

The reason we use the 10V/m is because our product will be used in a marine environment where the level is is determined by EN 60945. This is level 3 which is 10V/m. I think it is the same for industrial environments.

We did test at 3V/m above 3GHz and also had a failure at 3.2GHz.

Can you confirm that you have done the EN 301 489-1 immunity tests {9.2 Radio Frequency Electromagnetic Field (80 MHz to 6000 MHz} on the WROVER-B with PCB antenna? or on the WROVER-IB with external antenna?

[GustavVT]

Hi Grant,
Did you manage to work around the issue in the end?
We have had similar issues when doing radiated immunity testing using the ESP32-S3-WROOM-2-N32R8V module.
The performed test was the same as described in the original post, with a sudden loss of packets at around 800MHz.

Best Regards,
Gustav