I would probably characterize the level of Chinese radar technology somewhat differently. You're right about China has had quite a long history of developing large scale radar and was not as far behind the US/West as, say various engine technologies. But there are different types of radars, from large land-based radar, ship-based radar, to aircraft radar, with increasing challenges in that order. USSR/Russia also had a very long history in radar, but Russia today still struggles to develop AESA for its fighter aircraft.
A couple of tidbit stories may help illustrate the level and development of Chinese radar technologies, particularly AESA radars.
A lot of people are probably aware of the story of the development of Type 346 for 052C in the '90s, which was told by one of the lead engineers working on the project at the time who later immigrated to Canada. So China started developing ship-based AESA back in the 1990s.
In the early 2000s, China had contracted Israel to equip Israelis AESA-based system on its first batch of AWACS aircraft (IL-76). Israel canceled the project later under US pressure. The Chinese later said that although they did not get the radar from the Israelis but they did learn from Israelis to do quality control on mass production of the modules. I suppose this tells us that Chinese experiences before were mostly limited to large radars with limited quantity. Mass production of the modules with consistent quality was a challenge they learned to overcome later. So China successfully developed the aircraft-based early warning AESA radar in the 2000s.
Finally, when the Project 718 (J-20) was officially approved, it was said there were two potentially most critical barriers to success. One is obviously engine, the other radar. I remember reading comments from some key members of the CAC team that "it looked like AESA radar is no longer a concern" back when J-20 was still under active development. Cearly, China solved the fighter aircraft AESA problem in the early 2010s.
I'd agree with you that Chinese radar technologies are largely on par with the US today.
Yeah I recall when the J-20 prototype was revealed that those comments were also revealed. That was when Chinese radar technology was considered by Chinese military observers as going from unsurprisingly behind the US, to world leading competitive. I recall the same comments from then and much more excitement and interest was around for Chinese radars as it became obvious then that China had long already made huge strides forward. What I don't subscribe to by the time that excitement and literature came out is that China only caught up to leading edge standards then. The reality with all these types of Herculean engineering projects which wealthy and industrialised nations still require a lot of effort and resources invested into, is that they have been done LONG before they are revealed to be done.
By the time CAC engineers were allowed to whisper to family and friends about roughly where the tech levels are at, they have been achieved and surpassed on the ground already in reality. You don't spend multibillions developing a J-20 project to that prototype level where there are engine options but you don't have the radar surpassing even the strictest of conditions and tests. After all the J-11D's radars continued failing PLAAF's requirements and that's a second gen AESA by the late 2010s since J-16's and J-10B's even J-10C's at that timeframe have been in service for years ie developed and completed long ago.
Early 2000s Chinese AWACS program wanted Israeli and Russian expertise. They did have Chinese programs. The way China does things is just playing it safe with many layers of redundancy and security. We have our own first gen but we definitely also want to see how Israelis did it and how Russia did it. How anyone does it. The US is no different. Anyone would take a close look to learn, copy, improve their own if there is anything to learn, copy, and improve. At the very least, you learn how a potential adversarial platform works and performs. The US steals Russian and Soviet equipment whenever they get a chance. It's not always because they want to copy it... in fact quite rarely because of that
Early 2000s Chinese AWACS AESA technology indeed would be not comparable to China's today about 20 years onwards. Today, Chinese AWACS have how many platforms? more than I can pay attention to. How many generations, improvements, and iterations? certainly more than we know about. There's nothing to learn from Israel and the old master Russia but if China has the opportunity to get any AWACS platform, they would take it if nothing more than to study a potential adversarial platform that could be exported and purchased by country xyz.
At least China's radar and electronics technology went from (compared to leaders) non-existent (pre 1950s) to backwards (1950s to 1990s) to behind (1990s to 2000s) to competitive (2010s) to world leading (2020s). World's largest democracy has none of the technology, none of the academic and industrial basis, and none of proven production and working examples they actually made. While they talk about China copying, others have yet to even demonstrate an ability to learn and copy which China has been done with in these domains for some time but the morons haven't caught on to that. Despite being in such a highly interdependent world, China is one of the
very few which can do all this itself because it has the scientific and industrial means to make them. Cue the it's copied copes from usual bad losers.
