What's new

JF-17-BLOCK-3 Jet on mistake! if PAF switch PESA to AESA Radar,PESA radar r largely superior to AESA

Jhon Smith

FULL MEMBER
Joined
Dec 19, 2014
Messages
187
Reaction score
-2
Country
United States
Location
United States
Pakistan DefenceVerified account‏@defencepk
#Pakistan Air Force intends to upgrade all JF-17 Thunder fighters with advanced AESA radars including older blocks.
facebook]1116808918373907




ASEA Radar will be mistake of PAF, they should stay with mechanical one in preference of radar based on solid state tec (particularly AESA )!
The entire idea to replace Jf-17 radar just as similiar one to Eurofightr or US f-16 block-52 jet radars will be lapse at PAF scientific devision part!!


16762629922_7973410c69_b.jpg


IN REPLY TO THAT THREAD (https://defence.pk/threads/here-is-jf-17-block-iiis-aesa-radar-klj-7a.458854/)

AESA RADAR IS 70% LESS POWERFULL THAN PESA RADAR ON SPLIT WAVE

A passive electronically scanned array (PESA), also known as passive phased array, is a phased array radar which has a single central radio frequency source (such as a magnetron, a klystron or a travelling wave tube), sending energy into the multiple phase shift modules, which then send energy into the individual emitting elements in the front of the antenna. This contrasts with active electronically scanned array (AESA) devices, which have a separate radio frequency source for each phase shifter/emitting element. A PESA radar is therefore simpler to construct than an AESA.


AESA does have the ability to form multiple beams at different frequencies at the same time, but this is less common. If you are splitting up your beam into a beam for Freq-A and a beam for Freq-B, then each beam is now half as powerful and will get you (1/2)^1/4=84" position: relative of the range you would get if you were using the full array. Divide that into 4 sub-beams and now you’re down to 70% of your maximum range. You also lose monopulse processing which allows you to fine tune your angle measurement. Without monopulse, your angle measurement is only going to be as accurate as your beam width, and now with only half of an array, your beam just got wider. You typically don’t need this feature where you do two frequencies at the same time, because the radars are pulsed. Radars are emitting thousands of pulses per second. And after each dwell, you reset to a new target, re-steer the beam, and then send more pulses. Both AESA and PESA can track hundreds of targets at the same time.


Most phased array radars in the world are PESA. Microwave landing system uses PESA transmit-only arrays.
Radar systems generally work by connecting an antenna to a powerful radio transmitter to emit a short pulse of signal. The transmitter is then disconnected and the antenna is connected to a sensitive receiver which amplifies any echos from target objects. By measuring the time it takes for the signal to return, the radar receiver can determine the distance to the object. The receiver then sends the resulting output to a display of some sort.

The thought to convert Jf-17 radar as similiar to f-16 will be blunder of PAF scientists!


https://www.ll.mit.edu/publications/journal/pdf/vol12_no2/12_2devphasedarray.pdf
 
Last edited:
The thought to convert Jf-17 radar as similiar to f-16 will be biggest mistake of PAF


16762629922_7973410c69_b.jpg


IN REPLY TO THAT THREAD (https://defence.pk/threads/here-is-jf-17-block-iiis-aesa-radar-klj-7a.458854/)

AESA RADAR IS 70% LESS POWERFULL THAN PESA RADAR ON SPLIT WAVE

A passive electronically scanned array (PESA), also known as passive phased array, is a phased array radar which has a single central radio frequency source (such as a magnetron, a klystron or a travelling wave tube), sending energy into the multiple phase shift modules, which then send energy into the individual emitting elements in the front of the antenna. This contrasts with active electronically scanned array (AESA) devices, which have a separate radio frequency source for each phase shifter/emitting element. A PESA radar is therefore simpler to construct than an AESA.


AESA does have the ability to form multiple beams at different frequencies at the same time, but this is less common. If you are splitting up your beam into a beam for Freq-A and a beam for Freq-B, then each beam is now half as powerful and will get you (1/2)^1/4=84" position: relative of the range you would get if you were using the full array. Divide that into 4 sub-beams and now you’re down to 70% of your maximum range. You also lose monopulse processing which allows you to fine tune your angle measurement. Without monopulse, your angle measurement is only going to be as accurate as your beam width, and now with only half of an array, your beam just got wider. You typically don’t need this feature where you do two frequencies at the same time, because the radars are pulsed. Radars are emitting thousands of pulses per second. And after each dwell, you reset to a new target, re-steer the beam, and then send more pulses. Both AESA and PESA can track hundreds of targets at the same time.


Most phased array radars in the world are PESA. Microwave landing system uses PESA transmit-only arrays.
Radar systems generally work by connecting an antenna to a powerful radio transmitter to emit a short pulse of signal. The transmitter is then disconnected and the antenna is connected to a sensitive receiver which amplifies any echos from target objects. By measuring the time it takes for the signal to return, the radar receiver can determine the distance to the object. The receiver then sends the resulting output to a display of some sort.

The thought to convert Jf-17 radar as similiar to f-16 will be biggest mistake of PAF


https://www.ll.mit.edu/publications/journal/pdf/vol12_no2/12_2devphasedarray.pdf

Here's an interesting article that sheds further light on the subject and maybe help explain why the AESA makes sense for the PAF and most other modern airforces looking to the future.
https://www.quora.com/What-is-the-d...threats-at-different-direction-simultaneously
 
Last edited:
Why f16 v and block 60s were upgraded to AESA ? why all modern fighters are using AESA if its not up to the par.
This article is just explaining a limited information. A brief analysis is required for the final verdict.
in the end, PAF experts specifically and the other countries in general are not dumb to move on such tech which is having some serious flaws. there must be a reason.
 
A mix of PESA and AESA with excellent networking and data sharing capability is what we need. Consider a flight formation with a couple of different types to scanning radars, sharing data among themselves and using the information feed from various gadgets. Cost effective and much more efficient technically.
 
Last edited:
Pakistan DefenceVerified account‏@defencepk
#Pakistan Air Force intends to upgrade all JF-17 Thunder fighters with advanced AESA radars including older blocks.
facebook]1116808918373907




ASEA Radar will be mistake of PAF, they should stay with mechanical rather than solid state radar!The thought to convert Jf-17 radar as similiar to Eurofightr or US f-16 block-52 will be biggest mistake of PAF

16762629922_7973410c69_b.jpg


IN REPLY TO THAT THREAD (https://defence.pk/threads/here-is-jf-17-block-iiis-aesa-radar-klj-7a.458854/)

AESA RADAR IS 70% LESS POWERFULL THAN PESA RADAR ON SPLIT WAVE

A passive electronically scanned array (PESA), also known as passive phased array, is a phased array radar which has a single central radio frequency source (such as a magnetron, a klystron or a travelling wave tube), sending energy into the multiple phase shift modules, which then send energy into the individual emitting elements in the front of the antenna. This contrasts with active electronically scanned array (AESA) devices, which have a separate radio frequency source for each phase shifter/emitting element. A PESA radar is therefore simpler to construct than an AESA.


AESA does have the ability to form multiple beams at different frequencies at the same time, but this is less common. If you are splitting up your beam into a beam for Freq-A and a beam for Freq-B, then each beam is now half as powerful and will get you (1/2)^1/4=84" position: relative of the range you would get if you were using the full array. Divide that into 4 sub-beams and now you’re down to 70% of your maximum range. You also lose monopulse processing which allows you to fine tune your angle measurement. Without monopulse, your angle measurement is only going to be as accurate as your beam width, and now with only half of an array, your beam just got wider. You typically don’t need this feature where you do two frequencies at the same time, because the radars are pulsed. Radars are emitting thousands of pulses per second. And after each dwell, you reset to a new target, re-steer the beam, and then send more pulses. Both AESA and PESA can track hundreds of targets at the same time.


Most phased array radars in the world are PESA. Microwave landing system uses PESA transmit-only arrays.
Radar systems generally work by connecting an antenna to a powerful radio transmitter to emit a short pulse of signal. The transmitter is then disconnected and the antenna is connected to a sensitive receiver which amplifies any echos from target objects. By measuring the time it takes for the signal to return, the radar receiver can determine the distance to the object. The receiver then sends the resulting output to a display of some sort.

The thought to convert Jf-17 radar as similiar to f-16 will be biggest mistake of PAF


https://www.ll.mit.edu/publications/journal/pdf/vol12_no2/12_2devphasedarray.pdf



So mate one thing is confirmed
You aint no american from your skills with english...
 
@Jhon Smith

full


full


AESA have better LPI, more jamming resistant, robust and reliable and also gives advantage over power utilization and keeping weight and size from getting too big.

Also, before starting a thread on the disadvantages of AESA, the OP forgets the acquisition of the Rafale -- whose onboard radar also is an AESA. Even their evergreen ever in the making LCA is to be equipped with an AESA called "Uttam" in the future.

So only when a PAF fighter is about to get an AESA upgrade ... the OP thinks its a bad idea. Hence the two memes at the top, otherwise I do not resort to such means.
 
Last edited:
A mix of PESA and AESA with excellent networking and data sharing capability is what we need. Consider a flight formation with a couple of different types to scanning radars, sharing data among themselves and using the information feed from various gadgets. Cost effective and much more efficient technically.
But would it be easyy to get information from various information and show it as a single information for paf ? Information fusing is one of the most complex thing and is one of the prime function of f35 ...
 
I like to state the obvious that all 5th generation fighter aircrafts are using AESA radars.

Lets assume for the sake of discussion that PESA is better technology which will be incorporated in future versions of the 5th generation fighters.

When it comes to PAF, PAF is taking initial steps in introducing AESA radar (new tech in PAF) and even for AESA radar, more powerful engine maybe required in JF-17.

IMHO jumping directly for PESA radar may be a jump too far for PAF. PAF should follow the technological steps by sporting AESA before moving on to PESA. with above assumption, no doubt PESA may appear more attractive choice but with the current financial shortcomings, PAF decision makes should maintain a balance when it comes to selection of hardware for PAF.

P.S.: I hope that professional on PDF will spare discrepancies in my opinion due to my lack of knowledge in radars.
 
Last edited:
The primary advantage of AESA is logistics and SWAP (size, weight, power). With a PESA, you have a single high-power amplifier like the Klystron or TWT. These are older devices, require extensive cooling, and very prone to breakdowns. And when your single source of RF amplification goes down, your whole radar goes down and you are blind. They are expensive, fragile, and a single point of failure. With AESA, your “high-power” amplification is now split up between thousands of solid-state devices. Several of these AESA elements can fail, and the overall AESA performance will be essentially unchanged. The modules are circuit cards that can be manufactured much more easily, and technicians can easily switch modules in and out.

With PESA, you require a precision set of waveguides in order to get the high power signal from the common amplification source to all of the phase shifters. This ultimately makes the radar larger, it has special space constraints, it is heavier, and it is more difficult to manufacture. AESA radars only require a flat panel with all of the elements installed. Think of it as a frame with a bunch of circuit cards plugged in. The panel can be separated from the REX and connected only with cables allowing it to be more easily integrated onto different platforms.

AESA also allows the use of solid state devices for RF generation and amplification. Single solid-state devices were never capable of generating the power needed at a single source for a PESA radar. But when split up over thousands of elements, now you can use solid-state, and you end up getting much better radar efficiency, and can take advantage of modern solid-state advances in silicon technology.

and list goes on ......................
 
JF17 will have IRST in addition to the AESA radars either integrated or in an external pod.
 
The primary advantage of AESA is logistics and SWAP (size, weight, power). With a PESA, you have a single high-power amplifier like the Klystron or TWT. These are older devices, require extensive cooling, and very prone to breakdowns. And when your single source of RF amplification goes down, your whole radar goes down and you are blind. They are expensive, fragile, and a single point of failure. With AESA, your “high-power” amplification is now split up between thousands of solid-state devices. Several of these AESA elements can fail, and the overall AESA performance will be essentially unchanged. The modules are circuit cards that can be manufactured much more easily, and technicians can easily switch modules in and out.

With PESA, you require a precision set of waveguides in order to get the high power signal from the common amplification source to all of the phase shifters. This ultimately makes the radar larger, it has special space constraints, it is heavier, and it is more difficult to manufacture. AESA radars only require a flat panel with all of the elements installed. Think of it as a frame with a bunch of circuit cards plugged in. The panel can be separated from the REX and connected only with cables allowing it to be more easily integrated onto different platforms.

AESA also allows the use of solid state devices for RF generation and amplification. Single solid-state devices were never capable of generating the power needed at a single source for a PESA radar. But when split up over thousands of elements, now you can use solid-state, and you end up getting much better radar efficiency, and can take advantage of modern solid-state advances in silicon technology.

and list goes on ......................

Word for word copy of some paragraphs from the William Keim article I posted above (https://www.quora.com/What-is-the-d...threats-at-different-direction-simultaneously). Maybe you are William Keim if not please add the link that way we can read the article and be better informed or better still the article link has already been posted.
 
Word for word copy of some paragraphs from the William Keim article I posted above (https://www.quora.com/What-is-the-d...threats-at-different-direction-simultaneously). Maybe you are William Keim if not please add the link that way we can read the article and be better informed or better still the article link has already been posted.
dear brother .. this is an analysis to cut short the length of this thread, does it not informative? if yes then please eat mango rather than counting trees
 
Last edited:
dear brother .. this is an analysis to cut short the length of this thread, does it not informative? if yes then please eat mango rather than counting trees
Its copy paste, how do you not get that, the article is already posted, there was no analysis on your part. Also mangoes are currently out of season. Let it go.:-)
 

Back
Top Bottom