Add some range, and/or artificially limit radar power output, it isn't that hard.
P.s. my tablet PC doesn't like chinese Internet frequences,(goddamn Sony) so sometimes I miss pages and/or phrases, regardless of my wishes. :-(
Sukhoi can build anything similar to F-22 but why Russia has to make a copy and repeat the same aerodynamic limitation F-22 has?
Pakfa was designed as it is by design, the only limitation it has now it is its engine.
Stealth is a lot of propaganda, Lockheed is a monopoly, basically burning money while million of Americans can not afford housing or health insurance, what will they say F-35 is crap? of course not they will say it is wonderful it works so well.
No physical law says F-22 is undetectable, it is detectable, it is low observable upon some radar models.
Another big weakness is flight time they cost $25000-$34000 dollars an hour, basically they stay most of the time on the ground, to much sophistication means are delicate and break easily.
PAKFA was designed considering economic and military conditions thus excessive stealth was deemed foolish, building 5th generation is part propaganda, the reality is SAM and modern radars can cope with stealth aircraft at a lower cost, but business is business and Lockheed is a business.
Look at the F-35 of Israel down by a stork if we believe their story, so Lockheed makes bad bird strike tests but charge $100 million a piece.