@Figaro
This is what I mean by the J-20 will get clapped without assets. Its frontal RCS is way better than the rest of the aircrafts RCS much the like F-35. This scenario was copied off Quora, but it shows what I am talking about pretty much.
Let me explain: If a stealth plane, lets assume F-35, is flying directly “towards” the AWACS, then the chances of picking it up are extremely low because of the very small cross section of the plane from its frontal aspect. However, if the same plane is flying directly “away” from the AWACS, then the chances of detecting it are far greater because its cross section is much bigger from its rear aspect. So, an AWACS has to be positioned correctly in order to detect the F-35.
In real battle scenario, an AWACS will be backed up by other long-range radar equipped planes like Su-30 or F-15. Now the game turns on its head. Since the F-35 is being tracked from 2–3 aspects, and the AWACS has excellent data fusion capabilities, there is no chance that the F-35 can go undetected. Add to that Optical Sensors and Ground Radars! Almost 100% probability that the F-35 WILL be detected by the AWACS.