QFN (Quad Flat No-Lead) is very popular low cost package for RFIC, MMIC, and RF SiP applications. Most IC vendors use this package for their products. QFN packages perform pretty good up to 15GHz, showing less than -18 dB return loss with a typical package mounting scheme. However new designs require a higher operating frequency up to 20 GHz with the same package by optimizing the transition design on the circuit board.
The 3mm x 3mm,16pin RF QFN package performance is improved by optimizing the impedance of
input/output feed line and the transitional structure very quickly.