Chinese defense forums have posted copies of the image above which claim to cite the J-20’s AESA T/R module count at 1,856, the J-16’s at 1,760, and the J-10B at 1,200 T/R modules. It is likely the J-10B is the first Chinese fighter aircraft to feature an AESA; J-10B units achieved initial operational capability (IOC) in October of 2014. The volume of the J-10s nose cone is not substantially different from that of the F-16 or the Israeli Lavi from which the J-10 is partially based. Therefore, if one were to assume China had reached parity with the United States in packaging technology, the 1,200 T/R module figure would be plausible but slightly high. For comparison, the APG-80 AESA for the F-16C/D Block 60 has 1,000 T/R modules (DSB, 2001). However, it is unlikely that China has been able to reach parity with the United States in terms of packaging technology on their first generation AESA design. Neither Russia nor Israel was able to field 1,000 T/R element arrays within their first generation fighter mounted AESAs for similar nose volumes as the F-16 with the Mig-35 and Israeli F-16 respectively.
Russia’s first fighter mounted AESA radar, the Zhuk-AE, contained 652 T/R modules and was unveiled in 2007. The Israeli ELM-2052 AESA radar, which has been marketed for both the F-16 and the FA-50 – a joint Korean Aerospace Industry and Lockheed Martin F-16 derivative, has roughly 512 T/R modules (Trimble, 2014). The only firm outside of the United States that was able to produce a 1,000 T/R element within one generation was the French avionics firm Thales with its RB2E radar (Avionics Today, 2009). While the relative technological maturity of European, Israeli, and Russian AESAs is not directly indicative of the relative technological maturity of China’s packaging technology, it is an indicator that the first generation AESA produced by China is likely not on par with the US which is generally recognized as having the most technological mature T/R packaging technology (Kopp, 2014).
The prospect of China’s T/R packaging technology being on par with US firms within a single generation of radars is even more dubious when one examines the preference for an incremental technological development within the Chinese aerospace industry. Several Chinese aviation authors have hypothesized that the J-10B serves as a “technological stepping stone” with respect to the development of the more advanced J-20. For example, Feng Cao argues the J-10B and the J-16 AESAs were likely used to test technology related to the J-20’s AESA which would be a second generation Chinese design. By virtue of the larger nose volumes in the J-16 and J-20 airframes, it is highly probable the two aircraft will feature radars with more T/R modules than the J-10B’s radar.
The J-16 utilizes the Su-27BS airframe which has room for a 0.9-1.1 meter aperture in the nose which is on par with the F-15 and F-22 in terms of volume (Kopp, 2012). The 1,500 element N036 Tikhomirov NIIP AESA has a similar aperture size to the electronically scanned array (ESA) Irbis-E radar featured in the Su-35 series of fighters which shares the base Su-27 airframe. If the 1,760 T/R figure is correct it would indicate the Chinese aerospace industry has eclipsed Russian T/R module packaging technology as the N036 is arguably the most advanced Russian fighter mounted AESA. Similarly, the most advanced US fighter mounted AESAs such as the APG-77(V)2 and APG-82(V)1 contain 1,500 T/R modules*. While the prospect of Chinese avionics firms reaching parity with US and Russian firms is more plausible within two generations of designs, the author is skeptical the 1,760 figure is correct given the unsubstantiated nature of the image and the fairly substantial 260 T/R discrepancy between the J-16 radar figure compared to the most advanced US and Russian AESA designs. Therefore, the author speculates it would be more reasonable to assume a figure between 1,200 and 1,500 T/R modules for the J-16 rather than the 1,760 figure.
The tentative designation for the J-20's AESA is the Type 1475. While the nose volume of the J-20 is certainly large, the jet overall is longer and heavier than the F-22, no credible figures for nose volume were available at the time of this publication. As with the J-16 T/R figure, the J-20 figure is substantially greater than that of the most advanced US and Russian designs. Even if the Nanjing Research Institute of Electronics Technology (NRIET) or the China Leihua Electronic Technology Research Institute (607 Institute) was able to develop sufficient packaging technology that would enable 1,856 T/R modules within the J-20's nose, the density of the T/R modules would create significant cooling problems. For example, Phazotron's single greatest difficulty in designing the Zuk-AE was the AESA's thermal management system (Kopp, 2008). Without an effective cooling system, the Type 1475 would not be reliable at peak power output and would cause significant maintenance issues. Furthermore, with such a high number of T/R modules, the Type 1475 would be vulnerable to radar warning receiver (RWR) systems such as the ALR-94 without a very capable low probability intercept (LPI) mode.
*Type 1473 - The maximum detection range figures listed for the Type 1473 are from the EL/M-2032 which is arguably its closest analogue with published performance data (the Israelis supplied EL/M-2032s to China in the early 1990s which was developed into the Type 1473). The tracking and engagement figures for the Type 1473 are provided by Sinodefense.
