What is the Impedance Matching Point for the RF pin of ESP32-S3?

[M.Saad]

I have checked the datasheet, and the hardware design guidelines and searched on Reddit, FB, YT, and the usual Googling (checking several forums, including this one), however, I cannot find the impedance matching point for the RF pin of ESP32-S3 (QFN-56-EP 7x7mm).

I did find this info for some other ESP32s:
1) ESP32-C3 = (30~40±j10) Ω, Source: https://esp32.com/viewtopic.php?t=21649

Matching point is (30 ~ 40) ±10 j ohms, we will update this information on hardware design guidelines later.

2) ESP32-S2 = (34+j5) Ω, Source: https://cdn.sparkfun.com/assets/5/2/8/9 ... elines.pdf

The impedance matching point for the RF pin (pin2) of ESP32-S2 is (34+j5) Ω.

TIA

[M.Saad]

I was able to get confirmation from the ESPRESSIF team that the RF output impedance (impedance matching point) is (35+j0)Ω. It's available in the ESP32-S3 Hardware Design Guidelines, however, initially I didn't quite understand the wording in the new guidelines which caused the confusion.

Guide:
"In the matching circuit, define the port near the chip as Port 1 and the port near the antenna as Port 2. S11 describes the ratio of the signal power reflected back from Port 1 to the input signal power, the transmission performance is best if the matching impedance is conjugate to the chip impedance. S21 is used to describe the transmission loss of signal from Port 1 to Port 2. If S11 is close to the chip conjugate point (35+j0) and S21 is less than -35 dB at 4.8 GHz and 7.2 GHz, the matching circuit can satisfy transmission requirements."

Confirmation:
"Yes, the chip output impedance point and the point we debug are conjugate to each other (the imaginary number is opposite). Because it is +j0, the impedance point and the conjugate point are the same point."