I have updated my description about the MHL21336 amplifier at www.dd1us.de
Hi Matthias DD1US .
I made this amplifier using your schematic. I bought the module in september 2019 (Ebay) but i assembly this week. My module isnt counterfait. I supply with 28v in both pins and i have approximately 2 until 3 watts ( sorry, but i dont have how calibrate measurement equipment ).
I ordered so far 6 units. All of them marked brand new...
Two were dead on arrival, two had a short resulting from bad soldering of refurbished leads and two of them with "fake" modules.
I tested the fake and it does deliver over 10Watts at 2.1Ghz. However at 2.4Ghz it have about 0dB gain...
Anyway, importand to know that you must not feed all modules with voltage to Vdd1 before applying it to Vdd2.
It is not in the spec, but Vdd1 provide bias to the output transistor. LDMOS do not like VGS greater than VDS...
Nevertheless I notified the sellers and all of them refunded me with no negotiation..