I am interested in the group's recommendations and experiences with PCB layout using ESP32S3 boards with integrated antennas.
I am using an ESP32S3 DevKitC-1 in a socket on my PCB for prototyping and then will convert to a smaller version later. I have a 4 layer PCB - L1=signals, L2=ground, L3=power, and L4=signals.
I can envision 3 options for the antenna:
Have the integrated antenna hang over the edge of the PCB - recommended design from Espressif. Seems like a great opportunity to break or damage the antenna when handling the board, inserting the board into an enclosure, etc.
Create a copper exclusion zone under the antenna at least 15 mm from the edges of the antenna. Doable, but takes up a lot of board space, especially when the ESP32 is in the middle of the board.
Have the edge of the antenna just inside the edge of the PCB, and create a copper exclusion zone from the edge of the ESP32 to the edge of the board. Basically, the top ~6 mm of the PCB is a copper exclusion zone.
Have you ruled out using a module with an Ipex antenna of the sort that is delivered with, for example, the xiao esp32 s3 ?
Or your option 3 but actually cut the board away under the antenna instead of simply not putting any copper under it. Google for "cheap yellow display" and you see an example of this.
I do option 3, I use an ESP32S (not an S3) but that shouldn't matter. WiFi works fine no issues. I have the ESP32 mounted towards a corner to minimize space loss, though it does complicate the pin connections a little bit. (should be less for a 4 layer PCB than my 2 layer one) Keep in mind that ideally the rest of the ESP32 (everything but the antenna section) should be shielded using a GND plane (pin connection traces cab pass if needed) and should also act as a heatsink.
As I said in my original post, Espressif recommends hanging the antenna off the edge of the board. The implication of that statement is that I read that information in the Espressif documentation.