There you go again with your obfuscation and off tangent replies.RAM important on the air intakes, the edge treatment is the second most important.
Tertiary important is the general painting : P
According to the special AWST edition on “the state of stealth”, it basically affirms what is generally known on RCS reduction. RCS reduction is 90 % shaping and 10 % RAM. Engine contributes to 60 % of RCS issue. If you have no appropriate shaping and no engine blocker you basically have cow droppings.
Unless RAM is integrated into a radar-absorbing structure, the material adds weight and volume without aiding structural integrity. Stealth design has therefore dictated using shaping to control the largest contributor to RCS, specular reflections. The first true stealth aircraft, the F-117, employed a fully faceted shape to control these and saved RAM largely to deal with cavities and surface waves. (page 12)
The next stealth aircraft, Northrop Grumman’s B-2, was said to rely more on shape and less on RAM than the F-117. (page 13)
To suppress engine returns, the B-2 used a serpentine duct lined with RAM. Both shape and material are vital to this RCS reduction technique. The RAM is thin, but the inlet’s curve causes waves to bounce so many times the absorption adds up. Compared to a notional straight duct, an untreated serpentine inlet might achieve a reduction of 30 dB at boresight, but the advantage is zero outside 5 deg. off centerline. Add RAM, and RCS drops another 30 dB at boresight and stays 30-40 dB below unlined ducts, straight or curved, past 10 deg. (page 14)