Just curious...why continue with stealth? Especially after a F117 was shot down over the Balkans in1999, and the USAF has retired it?
First generation stealth. Flat surfaces effective at deflecting radar beams but not absorption and with limitations. In particular from directly underneath - which is where the Serbs placed their radar after the F-117s used the same route several days running. A lesson, as they say, was learnt from that.
Better computers for modelling means later aircraft have compound curve profiles and surfaces with inbuilt radar absorbent features.
As the science is one of measures, counter-measures, counter-counter-measures and diminishing returns.