Chengdu J-20 5th Generation Aircraft News & Discussions

[Tracy]

The Chinese AESA radar, now i want to see the Indian AESA radar.

Whats the difference between AESA and PESA Radar ? Can you tell in points it'll be easier to understand.

Wet Shirt , Gambit ?

 

[Wet Shirt Contest]

Whats the difference between AESA and PESA Radar ? Can you tell in points it'll be easier to understand.

Wet Shirt , Gambit ?

Here We Go,
. Active - Electronically Scanned Array (AESA)
. Passive - Electronically Scanned Array (PESA)


1) PESAs have a central rf source in the form of TWT or klystron, whereas in AESA each t/r module (which is a MMIC) has it's own power amplifier transistor

2) Because of this ability that AESA have much higher frequency agility than it's PESA cousin...

3) Normally in a PESA (FCR, x-band) , dual mode ferrite phase shifters are used, whereas in AESA all phase shifters are solid state electronic elements, ferrite phase shifters are more efficient than diodes, because of "switching times" of diodes, it can't reverse the direction at very high frequency bands like 8-12 ghz (x-band)

4) Each T/R module is a complete radar in itself,it is like this, all the components of a radar viz amplifier, LNA, duplexer, control circuitry is embedded on a single chip

5) Normally the phase shifters installed on PESAs have to deal with huge powers, whereas in AESA phase shifter power requirements are very les as compared to PESA

6) AESA can be partitioned in "sub-arrays" depending on the complexity of software coding running it, whereas this is NOT possible in a PESA

---------- Post added at 04:34 PM ---------- Previous post was at 04:31 PM ----------

So an AESA can perform all the tasks simultaneously, it can perform, scanning, tracking and ECM all at once

With the advent of GaN HEMT, now it is possible to achieve 80 watts/module..And radars with 250 kw are theoretically feasible, yet not in practicality, because of cooling requirements.

I Am Out For Now
Adios

 

[Edevelop]

The Chinese AESA radar, now i want to see the Indian AESA radar.

For some reason, the pilot in J-10B looks squeezed. Whereas in the F-16, it looks like it has far more room for the pilot.
Anyways aircraft performance wise, J-10B is indeed pretty good.

 

[SQ8]

When shaping is enough to lower RCS to below a certain level, absorber that will increase maintenance complexity and manufacturing costs while are of negligible benefits is no benefit at all.

I am familiar with a local effort here to produce a RAM tile which produced promising effects on a Mirage.. but the process to install .. adjust..and remove these tiles was very complicated and completely cost ineffective.

 

[j20blackdragon]

You really are confused aren’t you? Boeing has claimed that the Silent Eagle’s RCS is equal to export versions of the F-35, by ‘dumbed down’ the guy at Lockheed probably is refering to the export model of the F-35. Get it?

Prove that there is a degraded export version of the F-35.

Post some links and show your sources.

Partners to Get Equal JSF Stealth

Posted by Amy Butler at 6/22/2011 9:17 AM CDT

JSF partners and customers will be able to have the same stealth characteristics as the U.S., according to Joe Dellavedova, the F-35 program office spokesman.

Partners to Get Equal JSF Stealth

Brigadier Gen. David Heinz, program executive officer for the F-35, said Boeing was free to market its F-15 "Silent Eagle" plane, but rejected a claim by Boeing executives that Washington was selling a "dumbed down" version of the F-35 to international partners.

"I state categorically that I am not doing a different variant of aircraft for my international partners today," Heinz told Reuters in an interview at the Paris Air Show.

He said foreign countries who bought the F-35 would be subject to a U.S. disclosure process and U.S. export controls, but the aircraft being sold today were the same airplanes that were also being built for the U.S. military services.

"So for Boeing to make statements about a 'dumbed down' variant ... is absolutely incorrect and it is speculative and I believe, a very disappointing marketing ploy to drum up business," Heinz added.

AIRSHOW-UPDATE 1-Pentagon F-35 chief blasts Boeing comments | Reuters

My point is this. If a "dumbed down" version of the F-35 doesn't exist, that means Boeing is full of crap to begin with. They're comparing the F-15SE's frontal RCS to an aircraft that doesn't exist.

 

[Tracy]

Here We Go,
. Active - Electronically Scanned Array (AESA)
. Passive - Electronically Scanned Array (PESA)


1) PESAs have a central rf source in the form of TWT or klystron, whereas in AESA each t/r module (which is a MMIC) has it's own power amplifier transistor

2) Because of this ability that AESA have much higher frequency agility than it's PESA cousin...

3) Normally in a PESA (FCR, x-band) , dual mode ferrite phase shifters are used, whereas in AESA all phase shifters are solid state electronic elements, ferrite phase shifters are more efficient than diodes, because of "switching times" of diodes, it can't reverse the direction at very high frequency bands like 8-12 ghz (x-band)

4) Each T/R module is a complete radar in itself,it is like this, all the components of a radar viz amplifier, LNA, duplexer, control circuitry is embedded on a single chip

5) Normally the phase shifters installed on PESAs have to deal with huge powers, whereas in AESA phase shifter power requirements are very les as compared to PESA

6) AESA can be partitioned in "sub-arrays" depending on the complexity of software coding running it, whereas this is NOT possible in a PESA

---------- Post added at 04:34 PM ---------- Previous post was at 04:31 PM ----------

So an AESA can perform all the tasks simultaneously, it can perform, scanning, tracking and ECM all at once

With the advent of GaN HEMT, now it is possible to achieve 80 watts/module..And radars with 250 kw are theoretically feasible, yet not in practicality, because of cooling requirements.

I Am Out For Now
Adios

Ty I Saved all Info...I still didn't get all points clearly. Pretty Intense stuff to be honest
Sorry I know i am asking to many questions....but it's a defence forum with many valuable members so i expect nothing less


Q. What would be J-20's wing loading ?

Wikipedia Gives This Info only

Crew: one (pilot)
Length: 21.26 m (69 ft 9 in)
Wingspan: 12.88 m (42 ft 3 in)
Height: 4.45 m (14 ft 7 in)
Wing area: 59 m2 (630 sq ft)
Empty weight: 17,000 kg (37,479 lb)
Max takeoff weight: 36,287 kg (80,000 lb) upper estimate[2]
Powerplant: 2 × WS-10G (prototype); WS-15 when J-20 is serving afterburning turbofans dry, 180 kN (40,000 lbf) with afterburner
Maximum speed: Mach 2.5
Range: 5,500 km (3,418 mi; 2,970 nmi)
Combat range: 2,000 km (1,243 mi; 1,080 nmi)
Service ceiling: 20,000 m (65,617 ft)


Any Chinese Member Can help ?

 

[ChineseTiger1986]

Ty I Saved all Info...I still didn't get all points clearly. Pretty Intense stuff to be honest
Sorry I know i am asking to many questions....but it's a defence forum with many valuable members so i expect nothing less


Q. What would be J-20's wing loading ?

Wikipedia Gives This Info only

Crew: one (pilot)
Length: 21.26 m (69 ft 9 in)
Wingspan: 12.88 m (42 ft 3 in)
Height: 4.45 m (14 ft 7 in)
Wing area: 59 m2 (630 sq ft)
Empty weight: 17,000 kg (37,479 lb)
Max takeoff weight: 36,287 kg (80,000 lb) upper estimate[2]
Powerplant: 2 × WS-10G (prototype); WS-15 when J-20 is serving afterburning turbofans dry, 180 kN (40,000 lbf) with afterburner
Maximum speed: Mach 2.5
Range: 5,500 km (3,418 mi; 2,970 nmi)
Combat range: 2,000 km (1,243 mi; 1,080 nmi)
Service ceiling: 20,000 m (65,617 ft)


Any Chinese Member Can help ?

Yeah, pretty close to the actual stat of the production aircraft, but i think its maximum takeoff is going to be around 40 tonnes since it is a bit larger than F-22.

 

[nafsiati]

They had technology demonstrator set up in the early 2000's. It's been 10 years since then, so I imagine they have at least made some progress. As far as a operational TVC goes, not yet.

So what i want to ask is that in 5th generation fighter jets thrust vectoring is mandatory or just stealth with high performance avionics is enough? i mean thrust vectoring is a fifth generation mandatory feature?

 

[j20blackdragon]

Surface to air missile radars are on the ground looking up at your lower fuselage.

You gotta ask yourself which aircraft you would rather be in.

 

[ptldM3]

Surface to air missile radars are on the ground looking up at your lower fuselage.

You gotta ask yourself which aircraft you would rather be in.

My first suggestion would be to stop posting unessesary, off topic, and redundant photos that slow down everyone's computer. My second suggestion would be to stop acting like a little puke and show some respect or atleast contribute. My third Suggestion would be to minimize the J-20's underwing pods. They are down right rediculously large, so if i was you i would worry about those 4 giant warts hanging off the J-20's wing.

And here is photo that shows the pak-fa fuselage from a good angle with good lighting. Looks quite different doesn't? Quite flat even.

http://img845.imageshack.us/img845/9421/maks2011d6096.jpg

 

[kaykay]

Surface to air missile radars are on the ground looking up at your lower fuselage.

You gotta ask yourself which aircraft you would rather be in.

which aircraft is that (the first pic one)..??????????

 

[ptldM3]

It's an F-35 and there is no need to quote the entire post.

 

[Wet Shirt Contest]

Ty I Saved all Info...I still didn't get all points clearly. Pretty Intense stuff to be honest
Sorry I know i am asking to many questions....but it's a defence forum with many valuable members so i expect nothing less


Q. What would be J-20's wing loading ?

Wikipedia Gives This Info only

Crew: one (pilot)
Length: 21.26 m (69 ft 9 in)
Wingspan: 12.88 m (42 ft 3 in)
Height: 4.45 m (14 ft 7 in)
Wing area: 59 m2 (630 sq ft)
Empty weight: 17,000 kg (37,479 lb)
Max takeoff weight: 36,287 kg (80,000 lb) upper estimate[2]
Powerplant: 2 × WS-10G (prototype); WS-15 when J-20 is serving afterburning turbofans dry, 180 kN (40,000 lbf) with afterburner
Maximum speed: Mach 2.5
Range: 5,500 km (3,418 mi; 2,970 nmi)
Combat range: 2,000 km (1,243 mi; 1,080 nmi)
Service ceiling: 20,000 m (65,617 ft)


Any Chinese Member Can help ?

a Tricky Question InDeed,

1) However,this will depend in Few factors, first if it is built with simillar materials to the F-22 it will be heavier than 35 tonnes due to larger inlet dUcts, fuselage and fuel capacit

2)THe oTher factor is its degree of its longitudinal stability, if it is quit stable it will be slow at pitch, the wing position shows a long fuselage to reduce drag and increase internal volume but wings positioned quit back at the aircraft's aft End this is a result of a high wing position for both canard and wing in order to make canted nacelle walls for stealth p0rpuses, this will give it a rather stable configuration and thus quit sluggish response at pitch.

3) HavinG canards will mean the wing will lOse lift due to canard drag downwash increasing its real wing loading

4) If iT fAils to have higher tHrust engines than the USAF F-22's Pratt & Whitney F119-PW-100, it will be heavier but with less thrust to weight ratio and higher drag due to longer fUselage, this means it is not agile.

 

[kaykay]

It's an F-35 and there is no need to quote the entire post.

okay....hehe..your pc gets slow...lol

 

[Tracy]

a Tricky Question InDeed,

1) However,this will depend in Few factors, first if it is built with simillar materials to the F-22 it will be heavier than 35 tonnes due to larger inlet dUcts, fuselage and fuel capacit

2)THe oTher factor is its degree of its longitudinal stability, if it is quit stable it will be slow at pitch, the wing position shows a long fuselage to reduce drag and increase internal volume but wings positioned quit back at the aircraft's aft End,,,,,,,this is a result of a high wing position for both canard and wing in order to make canted nacelle walls for stealth p0rpuses, this will give it a rather stable configuration and thus quit sluggish response at pitch.

3) HavinG canards will mean the wing will lOse lift due to canard drag downwash increasing its real wing loading

4) If iT fAils to have higher tHrust engines than the USAF F-22's Pratt & Whitney F119-PW-100, it will be heavier but with less thrust to weight ratio and higher drag due to longer fUselage, this means it is not agile.

Informative Post Thankx......So Canards Are Good or Not Good For Agility ? What in In case of J20 ?
Is J20 a Bomber ?