J-20 5th Gen Fighter Thread VIII

[plawolf]

But the mission is always managed so the frontal cone, which can sometimes be 90 degrees wide, between the two big spikes that are wing's radar returns, is the one that is presented to the enemy. So as long as the plane is a few hundred km away from enemy perimeter, even the side views may not get to be outside the said cone. Plus the more to the side you are, the greater distance to the object you are looking at is gonna be. So even partial stealth there may be enough.

All this may be enough that long range aa missiles and stand off ag weapons are used. But all this is really for another topic. No one wants discussion to veer off into off topic.

Thats how you approach static ground based radars, and is a touch too idealistic even in that scenario as you always run the risk of getting caught out by surprise pop up new radars.

Against airborne adversaries, especially LO adversaries, it becomes a lot more challenging and complicated, as how do you know where to angle your optimal RCS window if you don’t know where opfor stealths are?

In realistic combat scenarios, it’s not unlikely that both sets of stealths will miss each other in the head-on approach, and it becomes a game to see who can catch the other side from a sub-optical angle. But no matter how you play the game, having a radar detection range advantage in terms of multiples of enemy radar range is a massive and potentially insurmountable advantage.

 

[tphuang]

Yes there are, F-35 is said to have the RCS of a golfball sized target in the frontal aspect which is roughly -30dBsm. As @Totoro mentioned, a competently planned mission will attempt to keep the enemy in the frontal cone as much as possible.

nobody knows the actual RCS of F-35 just as nobody knows the actual performance of the radar systems.

Just to give you an example, when China first tested on Irbis radar on Su-35 like 10 to 15 years ago, they "confirmed" it had 90 km range against 0.1m^2 target. Now, it might be easily jammable & easy to pick up, but that's what they said it could track. Now, if we go by the commonly held belief that J-16 radar is more powerful and that original J-20 radar is even more powerful, then we could easily be looking at 150 km vs 0.1m^2 for J-20 originally and something like 400 km vs 0.1m^2 now.

But all of that seems to just be playing with math. In real world, against jamming & cued with directional information by AWACS or naval search radars + using sensor fusion across many J-20As, what is the actual range? Nobody knows, it would be different based on the scenario.

But if we go by CETC claim that the new generation radar has 3x range vs before (let's be generous and say that's the difference between GaN-on-Sic vs GaA), then J-20A would easily go from having not workable range vs having workable range for engagement toward the edge of PL-16 NEZ.

 

[Gloire_bb]

Just to give you an example, when China first tested on Irbis radar on Su-35 like 10 to 15 years ago, they "confirmed" it had 90 km range against 0.1m^2 target. Now, it might be easily jammable & easy to pick up, but that's what they said it could track. Now, if we go by the commonly held belief that J-16 radar is more powerful and that original J-20 radar is even more powerful, then we could easily be looking at 150 km vs 0.1m^2 for J-20 originally and something like 400 km vs 0.1m^2 now.

There's likely no more powerful fighter radar than N035 around to this day; though this doesn't translate to anything useful other than range of pD=0.9 range against clear sky (ok, pD 0.5 may come handy against 20m targets in I-band for Korean Boeings; I'll see myself out).

The general trend of radar development is not power in the first place, it's better processing signal with better efficiency: if you'd want power, you'd go with 1960s radarmicrowave weapon Smerch-a (600kW peak) from mig-25...for barely 100km, unstable detection range.
This is especially true for modern fighter radars.

GaAs AESAs can't compete on emitted power with PESA, and even for GaN it isn't really true for power-specific applications alone (everything else though is so much better that there's no point even for raw power applications). This is the reason why, for example, AN/ALQ-99 family lived for so long: overcoming it on power-first application wasn't all that simple.
Single powerful transmitter is just not limited in the same way individual TRMs are.

GaN on SiC, maybe, but even that is arguably because no one develops PESAs anymore. And frankly in most cases it still won't be used for power.

 

[latenlazy]

There's likely no more powerful fighter radar than N035 around to this day; though this doesn't translate to anything useful other than range of pD=0.9 range against clear sky (ok, pD 0.5 may come handy against 20m targets in I-band for Korean Boeings; I'll see myself out).

Uhh isn’t the AN/APG-77 about the same peak power as the N035?

 

[tphuang]

It seems that the J20A has already adopted the radar technology of the next-generation fighter aircraft.

Meanwhile, the thrust-to-weight ratio of the J35A will also be quite high.


Here is a summary of the content of the "Yankeesama" talk show this episode:
1. The Type 100 tank has not been finalized. Due to the early start of the project, its anti-drone capability is not as strong. It will undergo intensive modifications within this year.
2. The Jiangnan Shipyard is highly likely not to have a new conventional-powered aircraft carrier. Skilled workers are going to Dalian Shipyard to assist in the construction of the Type 004 nuclear-powered aircraft carrier.
3. The Type 055 destroyer will continue to be built. The construction plan takes into account war damage.
4. The H20 bomber has some of its functions taken over by the Malan drones. The exact date of its maiden flight may disappoint aviation enthusiasts. It basically features a large aspect ratio, tailless, and stealth configuration.
5. The radar figure of the J-20a is extremely exaggerated. Yankeesama found it so astonishing.
6. The KJ3000 early warning aircraft may conduct joint training flights with the air force this year. The KJ700 represents the specialized functions of the air force's special aircraft.
7. The J-15 suffered several second-class accidents last year. The pilots were fine. It was an issue caused by the engine.
8.The thrust of the WS19 engine is similar to that of the basic model of the AL31 engine.

So now that I listened to the episode and I actually got different reading of what they said about J20A radar. They jokingly called it KJ20 and said essentially J20A has the most powerful aerial radar ever created.

the gap between J20A radar and APG85 is similar to that of F14 to Mig23 back in the days.

if I had to guess, easily 300 kw and probably 10x or more in peak power over the original J20 radar.

if we consider how large KJ2000 or KJ500 radar is, it’s quite amazing if J20A radar is more powerful than that.

and they also said that you could get scenarios where J20 get locked on and have no idea who is locking onto them. Similar analogy to jokes about J16 locking onto J7 when J16 first came out.

 

[tphuang]

Uhh isn’t the AN/APG-77 about the same peak power as the N035?

Yes, about 20kw. Most of the teens had aesa radar probably in the 15kw range. I would guess the initial J20 radar probably is in the same range.

 

[mack8]

So now that I listened to the episode and I actually got different reading of what they said about J20A radar. They jokingly called it KJ20 and said essentially J20A has the most powerful aerial radar ever created.

the gap between J20A radar and APG85 is similar to that of F14 to Mig23 back in the days.

if I had to guess, easily 300 kw and probably 10x or more in peak power over the original J20 radar.

if we consider how large KJ2000 or KJ500 radar is, it’s quite amazing if J20A radar is more powerful than that.

and they also said that you could get scenarios where J20 get locked on and have no idea who is locking onto them. Similar analogy to jokes about J16 locking onto J7 when J16 first came out.

Did you meant 30 KW or you really meant 300 KW?

 

[tphuang]

Did you meant 30 KW or you really meant 300 KW?

I mean what would be so impressive about 30kw? Even apg85 is around 80kw. I think 300 kw easily for j20a if you consider the much larger nose and the usage of higher voltage SiC substrate.

 

[Tomboy]

So now that I listened to the episode and I actually got different reading of what they said about J20A radar. They jokingly called it KJ20 and said essentially J20A has the most powerful aerial radar ever created.

the gap between J20A radar and APG85 is similar to that of F14 to Mig23 back in the days.

if I had to guess, easily 300 kw and probably 10x or more in peak power over the original J20 radar.

if we consider how large KJ2000 or KJ500 radar is, it’s quite amazing if J20A radar is more powerful than that.

and they also said that you could get scenarios where J20 get locked on and have no idea who is locking onto them. Similar analogy to jokes about J16 locking onto J7 when J16 first came out.

I'm not sure if you are getting the meaning, KJ-20 is referring to what we call KJ-3000. They actually mentioned this sometime ago that KJ-3000 isn't actually called that but instead KJ-20.

 

[tphuang]

I'm not sure if you are getting the meaning, KJ-20 is referring to what we call KJ-3000. They actually mentioned this sometime ago that KJ-3000 isn't actually called that but instead KJ-20.

Oh in that case then I totally misunderstood the part about the KJ20 then and the most powerful aerial radar ever. The rest of the stuff comparing APG85 to J20A radar and such still holds.