Thanks for all your reply

I get that I have to add an inductor on XTAL_P. According to the datasheet it should be around 20nH, right ?

For the crystal I took one from a dev board which works well (I took caps too) it didn’t solve the issue.

My antenna is 50ohm, ESP32C3 is 35+j10 ohm (if I ...

thanks for your reply.

I use this crystal I bought here https://fr.aliexpress.com/item/1005002359133404.html?spm=a2g0o.order_list.0.0.1df55e5bvL1NlO&gatewayAdapt=glo2fra

It's a 40MHz SMD Quartz Resonator Crystal. they don't give the ppm value neither the right caps value.

As I found in other ...

you can look at this topic for impedance matching circuit
https://esp32.com/viewtopic.php?t=26106

the esp32C3 / S3 seems to be 35+j10 ohm
your antenna is usually 50 ohm

So the matching circuit seems to be 4.7pF / 1.8nH / 3.9pF (rounded to classic values)

hello everyone

I'm working on a custom PCB board based on ESP32-C3FH4.

but the HF part doesn't seem to work correctly :(

according to this topic https://esp32.com/viewtopic.php?t=26106 I set the matching impedance to match with a 50ohm antenna.

I tryed to keep the antenna as far as possible ...

hi

I had a similar issue.
I saw in your PCB you didn't had the capacitors close to the oscillator.

adding them solved my issue.

I hope it help you