I'm designing a PCB with a ESP32-PICO-V3, with a RF output to a 50 Ohms U.FL (Micro-Coax) connector. The chip supports WiFi and Bluetooth in the frequency range 2.45 +/- 0.45 GHz.
Right now, I have a prototype with a 0 Ohms resistor in lieu of the CLC filter suggested in the Hardware Design Guidelines (pdf), which also states that the output impedance of the chip is ~(30 + 10j) Ohms (for the 6x6mm package, I have the 7x7), and I get 45 Mbps with iPerf test.
However, I'd like to improve the circuit with a true LC Balun filter. According to this site (and a few others), I get the following design::.
My guess is that it will work however I do it, since it already works with no filter or matching. But I want to minimize EMI right from the start. Otherwise, should I just follow the guideline of putting a CLC filter and be done with it?
Other info: the stackup is Er = 4.05 and height = 3.5 mils. Traces are 6 mils wide.