A 2011 analysis of J-20 RCS on a scale model coated with publicly available RAM formula against 8GHz frequency of fire-control radars.
Pic 1: Front
Pic 2: Back
Pic 1: Front
Pic 2: Back
Pic 1: Top
Pic 2: Bottom
Pic 3: Side
Pic 2: Bottom
Pic 3: Side
Pic 1: Angled from the bottom
Pic 2: Angled from the top
Pic 2: Angled from the top
A comparison of vs F-35 RCS at different frequencies
Source: basicsaboutaerodynamicsandavionics.wordpress.com
Source: basicsaboutaerodynamicsandavionics.wordpress.com
The same source also did one for the J-20 as well.
Source: basicsaboutaerodynamicsandavionics.wordpress.com
Source: basicsaboutaerodynamicsandavionics.wordpress.com
The summaries they drew for both planes are as follows:
J-20 RCS is higher than F-35A RCS through the frequency range (approximately 3.5 times in X-band, 1.5 times in VHF band) [...] The canard return blended very well with the main wing return
J-20 RCS is higher than F-35A RCS through the frequency range (approximately 3.5 times in X-band, 1.5 times in VHF band) [...] The canard return blended very well with the main wing return
Due to their high swept angle, the first high RCS spike of J-20 actually located at around 50 degrees boresight. This mean it is very easy for J-20 pilots to keep enemy adversary within their stealthy sector.
Add to the fact that J-20 has very big antenna aperture, it can be highly lethal in BVR combat.
On the F-35:
Capable of retaining very low RCS as long as the pilot can keep his adversary inside the 40° frontal arcs.
Capable of retaining very low RCS as long as the pilot can keep his adversary inside the 40° frontal arcs.
Even without the RAM on outer skin surface, and without leading edge and trailing edge treatment, the F-35 model is able to achieve the median RCS value of only 0.06 m2 in X-band, increased only to 0.13 m2 in L-band.
The external AIM-9X along with pylon seem to have negligible effect on the total overall RCS of F-35, in fact, in some case, the destructive interference effect actually help reduce the RCS value in some direction
F-35 has very strong reflection spike located at around 34-35° boresight which could be critical weakness in certain situations.
Resonance effect of VHF frequency increase RCS of the aircraft significantly from most direction except directly ahead. Hence, a group of connected VHF radars could be very useful toprovide early warning against stealth fighters such as F-35A.
The immediate conclusion is that although the J-20 is bigger than the F-35, its RCS isn't THAT much bigger. Its lethality in BVR combat is further enhanced by VLAAMs like the PL-15 and the J-16 carried PL-17 (fmr PL-XX)
China has been cranking the J-20s out at an absurd rate. Far faster than most estimates gave them credit for. As they activate more J-20 brigades, the platform can and will play an important role in blunting US airpower in WESTPAC
Loading suggestions...