Radar stealth was a busted flush - proved so in the 1980s with bistatic radar.
See IEE publication 1993, Advanced Radar Techniques and Systems edited by Gaspare Galati, Chapter 11 by M R B Dunsmore of the Royal Signals and Radar Establishment, Malvern.
All that money pumped into pretending aircraft can be made invisible to radar....wasted. Good article here:
Russian / PLA Low Band Surveillance Radar Systems (Counter Low Observable Technology Radars)