J-20 5th Gen Fighter Thread V

Status
Not open for further replies.

Hyperwarp

Captain
so how many T/R modules on J-20 ?

Not sure. I have heard 1856 to 2200+. 1856 T/R modules seems to be the initially accepted value. Off-course Processing power has changed a lot since AN/APG-77 days. For example F-22 uses
Please, Log in or Register to view URLs content!
CPUs.

If PLAAF/Chengdu play their cards right, they should have a significant upper hand is sheer processing power. Whether they will use it effectively is another matter.

Please, Log in or Register to view URLs content!
 

Blitzo

Lieutenant General
Staff member
Super Moderator
Registered Member
Packaging size is another factor. A bigger radome may not mean a more powerful radar.

Packaging, processing, cooling, will all influence the peak power that could be attained...
I think the comparisons between J-20's larger radome potentially meaning a more powerful radar compared to F-22 is assuming that factors above (and others) are at least equal in J-20's radar. I think the first APG-77 was delivered for integration in 1998, whereas the first J-20 radar probably would've finished development about 2012. Who knows where J-20's radar stands in comparison to APG-77 when it first emerged.
 

antiterror13

Brigadier
Packaging size is another factor. A bigger radome may not mean a more powerful radar.

if everything else the same, we can safely say the bigger means more powerful radar

I don't think current Chinese CPU is worse than the 1995 American CPU :p

Remember Chinese still hold the most powerful supercomputer in the last 3-4 years (TIANHE-2) with Linpack Performance (Rmax) 33,862.7 TFlop/s

And all Chinese Supercomputer ranks 14 in Nov 2011 (Sunway Blue Light) and rank 103 in Nov 2015

Sunway has Linpack Performance (Rmax) 795.9 TFlop/s and the best supercomputer in 1995 was Numerical Wind Tunnel with Linpack Performance (Rmax) 0.17 TFlop/s
 
Last edited:

Brumby

Major
if everything else the same, we can safely say the bigger means more powerful radar

I don't think current Chinese CPU is worse than the 1995 American CPU :p
It doesn't work this way in radar technology.

so how many T/R modules on J-20 ?
There are three things that determine the number of T/R modules. Firstly, the physical size of the aperture is obvious in that the more space available the more modules that can be packed. Secondly is the available packaging technology that enables an optimal density corresponding to the third determinant i.e. targeted frequency. All fighter planes with radar essentially operates in the "X" band which has a frequency range but for simplicity say it is 10 GHz. This translates to a 3 cm wavelength. The rule of thumb for T/R spacing is half a wavelength apart which gives a 90 degree FOV without any grating lobes.

P.S. Mod. This should probably move to Chinese radar thread.
 

Attachments

  • upload_2016-2-8_20-4-12.png
    upload_2016-2-8_20-4-12.png
    79.2 KB · Views: 83
Last edited by a moderator:

Hyperwarp

Captain
Lots of processing power alone is certainly not enough. After all, no point having Core-i7 6700K if the software sucks. I heard many rumors that the KJ-2000s computing power is well above the rest of the world but initially the Radar was more susceptible certain types of jamming compared to the western counterparts. I think this was disclosed by the chief designer himself during a documentary. So the computing power is just one aspect. So like I said before, if PLAAF+CAC play their cards right, they should have a very formidable system.
 

antiterror13

Brigadier
Lots of processing power alone is certainly not enough. After all, no point having Core-i7 6700K if the software sucks. I heard many rumors that the KJ-2000s computing power is well above the rest of the world but initially the Radar was more susceptible certain types of jamming compared to the western counterparts. I think this was disclosed by the chief designer himself during a documentary. So the computing power is just one aspect. So like I said before, if PLAAF+CAC play their cards right, they should have a very formidable system.

who said "computing power" is the only factor? not me :p

I don't disagree with all you said, but computing power is one of the most important factors
 

latenlazy

Brigadier
if everything else the same, we can safely say the bigger means more powerful radar

I don't think current Chinese CPU is worse than the 1995 American CPU :p

Remember Chinese still hold the most powerful supercomputer in the last 3-4 years (TIANHE-2) with Linpack Performance (Rmax) 33,862.7 TFlop/s

And all Chinese Supercomputer ranks 14 in Nov 2011 (Sunway Blue Light) and rank 103 in Nov 2015

Sunway has Linpack Performance (Rmax) 795.9 TFlop/s and the best supercomputer in 1995 was Numerical Wind Tunnel with Linpack Performance (Rmax) 0.17 TFlop/s
A radar is not the same thing as a CPU.
 
Status
Not open for further replies.
Top