NIIP Bars and Irbis series of radar for Su-30/Su-35

Anduriel said:
But old Bars design?
Click to expand...

Yeah, definitely. There were also "Bars-23" and "Bars-29" for MiG-23 and MiG-29 sized aircraft. and they're all "scaled down" N011M Variant. Also not counting "Osa" which destined for MiG-29 and MiG-21.
 
Irbis-e can scan without physically turning the aperture, but the aperture can turn to improve the field of regard. Do you guys think the pilot can steer the aperture a certain way to reduce the RCS of the aircraft?
 
Vanessa1402 said:
Irbis-e can scan without physically turning the aperture, but the aperture can turn to improve the field of regard. Do you guys think the pilot can steer the aperture a certain way to reduce the RCS of the aircraft?
Click to expand...
In theory it's possible. Whether it's actually implemented that way is yet another question. It must be noted that the mechanical steering is basically limited to azimuth though.
 
Scorpion82 said:
Vanessa1402 said:
Irbis-e can scan without physically turning the aperture, but the aperture can turn to improve the field of regard. Do you guys think the pilot can steer the aperture a certain way to reduce the RCS of the aircraft?
Click to expand...
In theory it's possible. Whether it's actually implemented that way is yet another question. It must be noted that the mechanical steering is basically limited to azimuth though.
Click to expand...
are you sure about that?, I vaguely remember it can turn in any direction
 
To my understanding the rotational movement copensates for bank only, but isn't used to extend elevation coverage.
 
View: https://m.youtube.com/watch?v=xcdYVZrwHik
Bars video



The Su-35’s air-to-air Phazotron NIIP N-011 multi-mode, look-down/shoot-down radar (which also has an air-to-ground capa- bility out to a range of 124 miles) is sophisti- cated but not up to state-of-the-art Western standards. Typical of Russian radars, it depends more on its enormous power than on sophistication to accomplish search-and- track tasks and overcome countermeasures. Regardless, Sukhoi claims the unit can track up to 15 targets simultaneously while it engages any six at ranges of up to 249 miles. Few Russian aircraft observers truly believe the latter, but military strategists often use it anyway for threat analysis purposes.
Click to expand...

Those numbers are pretty out of line with what I’ve heard about Bars MSA but I wonder where they came from?
 
I dont understand a lot of the intricate details of radio electronics and deeply admire stealthflanker types who are gifted with mathematical and engineering acumen. That said I think it is much more complicated than "it isnt aesa". From all I can gather the irbis e is one of the most powerful pesa radars ever made with functions built in to keep it very competitive. From what I gather the beam steering and agility and bandwidth and power are near peer to even very modern aesa radars. There are certain key features missing tho like LPI and the flexibility of having myriad transmitters as opposed to only one with a few concurrent channels.

Can someone with much better knowledge speak on this when they have the time? If I am wrong on anything please correct me and rip what incorrect stuff I've said apart. For example am I right about pesa radars not having LPI ability as it only has a single powerful transmitter? I know irbis is unique in that it does have hundreds of recieve channels but this is a huge difference between pesa and aesa right?

Edit: had to add a thought.
 
Doing radiating element counts for Irbis. Although it's PESA, it is still a Phased array radar where the number of radiators matter.

Irbis-Counting.png

From the counts, one can try glean into some parameters e.g antenna gain from simple equations and some basic assumptions.

For gain it can be found from :
G=N*PI()*Efficiency

Where N is the element counts, Pi is pi (3.14 something) and Efficiency, the efficiency factor here for phased array are determined via its radiation pattern, which would mean knowing the weighting function for the antenna allows first cuts for estimating efficiency. The typical and relatively popular weighting function is Taylor -40 dB which give beamwidth broadening factor (k) of 1.25 and aperture efficiency of 0.76.

Using the factor into the Irbis element counts yield 36.4 dB. About 0.4 dB more than Bars despite smaller diameter (0.9 vs 1 m) of Irbis.

Knowing the element counts may also frequencies to be estimated too. This however also requires that the physical antenna aperture (or at least the part of the aperture that occupied by the radiators) to be known. Irbis however have publicly available information of 0.9 m diameter, thus physical area of 0.63 sqm. This can then be divided by the Element counts to find the element area. This element area can then be directly used to estimate operational wavelength through the Squared wavelength/4 relationship.

From above, the element area is found to be about 0.0003 sqm. Operational wavelength would then be 0.0369 m or 8120 MHz.

Antenna beamwidth can also be approximated by simple relationship 100/Sqrt(N) Which for the element counts, yield 2.3 Degrees.

One confusion i have is the element spacing. Most relationship i cited above assumes half wavelength spacing for the antenna. There is however means of optimization like element placement (square grid vs triangular lattice) which allow for thinning of the array vs scan angle requirement tradeoff. This element spacing confusion in turn will affect the estimated value of frequency.

The other relationship i read for triangular lattice, which seems to be the arrangement Irbis used puts the element area equation to be 0.332*Squared wavelength. Thus using this relationship give me frequency estimate of 9356 MHz (0.032 m wavelength)

The antenna frequency bandwidth, beamwidth estimates and gain is unaffected. At least before i start digging more relationship.

Range estimates using K.Barton's equation for Modern Radar, using available public informations along with values established above yield range estimates of some 408-385 km for 3 sqm SW-1 target with PD 0.5% and 257-243 Km for 90% PD. Assume the Dwell time per beam to be 0.03 seconds similar as Zaslon and that 10x10 degrees search area. It will completes the scan in 0.55 seconds.

If Wide angle search is assumed (e.g 120 deg and 7 Bars) Same detection range can be achieved with same dwell time but the whole scan time would be 9.28 Seconds. Is that acceptable ? What if faster scan is desired. e.g 5 seconds. Halving the dwell time (now 0.015 seconds/beam) drops the detection range to 320 km for 50% PD and 204 km for 90%.

So i feel that the informations publicly available is actually true. at least for noise limited condition like above. Clutter however will present challenge which depends on what kind of "Improvement factor" the signal processing can allow and how much sidelobe reduction Irbis antenna could have. This however is harder to find in public source. There are descriptions from Chinese forum about Irbis's "supposedly inferior range" But given there are no hard value nor condition of the flight was given or target informations (e.g speed, altitude). It will be difficult to make any estimates.

I "developed" some simplified method for calculating range vs Surface clutter condition but it's rather crude and only counts mainlobe clutter contribution. No means to calculate improvement factor available yet.
 
BARS range 110km for a 3sq meter target. That’s a hair greater N001, though I’m such detection quality is much better. That seems similar to the difference between N019 and Zhuk-ME.
 

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The inconsistency is probably caused by use of range of different PD and PFA's. Bars has always been credited with 250-300 km range. It could be however for PD-50%, while the 110 km range figure is for PD-90%.
 
stealthflanker said:
The inconsistency is probably caused by use of range of different PD and PFA's. Bars has always been credited with 250-300 km range. It could be however for PD-50%, while the 110 km range figure is for PD-90%.
Click to expand...
There isa simple answer - mid-life upgrades. I saw a picture from presentation where was timieline of Indian N011M variants. with first variant being purely A2A, with A2G and other improvements coming through with upgradesand new production blocks.
 
Anduriel said:
There isa simple answer - mid-life upgrades. I saw a picture from presentation where was timieline of Indian N011M variants. with first variant being purely A2A, with A2G and other improvements coming through with upgradesand new production blocks.
Click to expand...

That cant explain differences and inconsistencies in range figures tho.. like Initial N011M Bars was always rated for at least 150 km range for a "fighter" sized target then it's credited with 330 km range for Su-27's. That's in some 2005's, now is 2024.
 
stealthflanker said:
That cant explain differences and inconsistencies in range figures tho.. like Initial N011M Bars was always rated for at least 150 km range for a "fighter" sized target then it's credited with 330 km range for Su-27's. That's in some 2005's, now is 2024.
Click to expand...
N001VEP also has 150km range for its long range search. I notice a number of Russian radars have similar range to their equivalent. Like Zhuk-ME and N019M1.
 
stealthflanker said:
Yeah but not sure if you can compare it with Bars, as it's a much newer more advanced design.

That 150 km range is probably obtained through very long dwell time, which may not be realistic for combat scenario.
Click to expand...
I’m actually curious, as I understand it some parts of the N001VEP might be better, like the Baguet series 55-04.02 processors were not used on (at least the initial variants) of Bars. Bars seems to have been forced early on to rely on legacy Soviet components, I’m not sure what later upgrades entailed.
 
Im wondering if Irbis has Space Time Adaptive Processing featured in for ground slow moving targets detection and cancelling jammers?
 
TMA1 said:
I dont understand a lot of the intricate details of radio electronics and deeply admire stealthflanker types who are gifted with mathematical and engineering acumen. That said I think it is much more complicated than "it isnt aesa". From all I can gather the irbis e is one of the most powerful pesa radars ever made with functions built in to keep it very competitive. From what I gather the beam steering and agility and bandwidth and power are near peer to even very modern aesa radars. There are certain key features missing tho like LPI and the flexibility of having myriad transmitters as opposed to only one with a few concurrent channels.

Can someone with much better knowledge speak on this when they have the time? If I am wrong on anything please correct me and rip what incorrect stuff I've said apart. For example am I right about pesa radars not having LPI ability as it only has a single powerful transmitter? I know irbis is unique in that it does have hundreds of recieve channels but this is a huge difference between pesa and aesa right?

Edit: had to add a thought.
Click to expand...
While I'm largely in the same boat, I want to say that one of the key differences between The Irbis-E & traditional PESAs is the addition of more power via the installation of a second traveling wave tube that, along with improved signal processing & everything else, enhances the overall sensitivity of the radar while also doubling the number of simultaneously tracked & prosecuted targets in comparison to older models, which, interestingly, is also the very same approach that was adopted by The Patriot, although the newer radars are/will be AESAs. Why Russia does not do the same with their Pantsirs, Tors, Buks, S-300s, S-350s, & S-400s, etc., makes absolutely no sense to me.

Bottom line - The Irbis-E essentially represents a kind of middle ground between standard PESAs & AESAs. I think.
 
Joint Soviet Fighter said:
While I'm largely in the same boat, I want to say that one of the key differences between The Irbis-E & traditional PESAs is the addition of more power via the installation of a second traveling wave tube that, along with improved signal processing & everything else, enhances the overall sensitivity of the radar while also doubling the number of simultaneously tracked & prosecuted targets in comparison to older models, which, interestingly, is also the very same approach that was adopted by The Patriot, although the newer radars are/will be AESAs. Why Russia does not do the same with their Pantsirs, Tors, Buks, S-300s, S-350s, & S-400s, etc., makes absolutely no sense to me.

Bottom line - The Irbis-E essentially represents a kind of middle ground between standard PESAs & AESAs. I think.
Click to expand...
well, maybe this helps slightly, old, dead source , but technically enough:

https://www.ausairpower.net/APA-Flanker-Radars.html

There is described "difference" between traditional PESA and "hybrid PESA" used in late Flankers...

From description of BARS radar..:

"
The BARS is the most advanced radar developed by Russian industry during the 1990s. It is unusual in being designed with a hybrid array arrangement, the receive path using very similar technology to US and EU AESAs, with similar sensitivity and sidelobe performance, but using a Travelling Wave Tube and backplane waveguide feed for the transmit direction, a technology closest to the B-1B and early Rafale EA radars. As such the BARS is a transitional design sitting in between Passive ESAs (PESA) and contemporary AESAs. There is no doubt this design strategy reflected the unavailability to Russian designers of the Gallium Arsenide power transistors used in Western AESAs.

The baseline N011M radar uses a vertically polarised 0.9 metre diameter aperture hybrid phased array, with individual per element receive path low noise amplifiers delivering a noise figure cited at 3 dB, similar to an AESA. The antenna is constructed using phase shifter and receiver 'stick' modules, a similar technology to early US AESAs."

Some comment. Typical, classical PESA was made from single high power generator - like TWT (Klystron). The power was provided by set of waveguides (typically in planes) or optically (generally in ground systems..) to array of passive elements - phase shifters.
Those elements , (like ferrite phase shifters) are controlled electronically and changes phase of each emitted signal.

Signals from all radiating elements forms single beam that is send. Refected from objects... very very weak signal reaches back antenna. The same passive shifters, designed both for handling high power, now are used to shift received signal, with exactly the same phase shift. Next... signals, weak signals, from all array elements are passed and summed to the receiver. Here low power receiver, can finally gain signal and pass to further processing...

This arrangement, has many drawbacks. Array was usually heavy, and has other disadvantages (and advantages).
But from signal and efficiency point of view, this looks like: high power energy is transmitted... first time ,,, some amount of power is lost in wave-guide while on send ... Next ...other power is lost in passive shifters ... On receiving similar happens... very weak signal ... first goes pass by passive snifters, this reduce energy, but worse is that those elements have own noise which is somehow added to very weak signal... then waveguides (once again reduction and noise) and finally this very weak signal reaches to amplifier...
This impact sensitivity. "noise figure" of early PESA was higher than conventional plate arrays (for example +6dB or more comparing to other design).
Lower sensitivity, and losses of power impacts range, that might be lower than in conventional designs, with the same array size and transmitter power.

Of course PESA had other features those, can somehow mitigate above mentioned drawbacks, like:
- possible bigger antenna size in the same airframe - as array could be fixed.
This somehow mitigates decrease of range , as - at least when target is in front of antenna: as effective array area might be higher than in conventional designs...
But for higher angles from array axis, effective array area drops significantly and fast... ( cousins of angle ..). As the array size has tremendous impact on radar performance (gain an beam with) - advantages were rather only for targets in front of plane.

- scanning might be adaptive... with for example dual detection threshold.. usually it was possible to use lower threshold..
In classical design this would lead to high false alarms ratio... as noise ... incidentally might cross threshold.
So in conventional radars, this need to be set high enough to pass only strong signals , and limit false alarms.
But in PESA lower threshold might be used... once signal cross threshold... scanning might immediately stop at that position to check if this is true object or false positive. And it can stay at that position more time than in classical design - to collect more energy. (It can even do monopulse precise coordinate estimation.... if required)

But generally those drawbacks of PESA were very severe. Solution was (analog) AESA in which:
- low power microwave signal is passed from common source via low power wave guides to emitting elements. Here , low power phase shiftier could be applied. Moreover energy of each elements can be precisely and dynamically set. This form "tapering" function - which reduces emitted sidelobes. Finally low power signal to be emitted is amplified in local power transistor . And that is just directly behind emitting elements.. no power is wasted...
- on receive side - is similarly , but in reverse order... very weak signal is directly amplified by receiving, low power, low noise transistor, "just below" the array. NO additional noise is added... this initially gained signal is (either down converted to intermediate frequency, or not) passed via phase shiftier and wave-guides to next stages of receiver.. But as signal is initially gained... noise of other elements has almost no impact on sensitivity.. hence cited above "low noise factors of AESA"

(The next step is digital AESA - where signal to and from elements are passed in digital form... but this is just different story,,,)

Returning to BARS... and IRBIS ... they claimed that this is "hybrid" design. In emitting way - it seems to be very similar to classical PESA.. with all drawbacks... in loosing some energy... lower frequency agility and so on...
But on receiving path .. this looks like more like AESA (at least if we cite the above article). So with low power, low noise transistors just below array and so on. So it might have high sensitivity comparable to AESA. And as author claims... Russian decided on that design, causes they have no technology to produce array of GaAs power transistors. But at reciving part - this is like AESA... even with possibility applying tapering function to reduce sidelobes.

Of course both PESA and AESA design has the same "problem" with high angles targets... parameters of those arrays decreases for high of boresight angles... To mitigate that - cheek arrays are used (like in Su-57) or movable PESA/AESA arrays - like in Su-35 , Grippen or Typhoon...

And comparing Irbit to BARS... BARS was further development of late 80tees design using PESA technology, technology developing that time for N-014
They assembly BARS - developed and made mature design in 90tees. And having this mature design, and experience, after decade, having much more sophisticated components of early 00', just did step further - doing BARS again, but with much more modern elements... This results, as you mentioned , with double transmitter of much more energy, thinner and more nimble antenna, better ..everything...
 
The baseline N011M radar uses a vertically polarised 0.9 metre diameter aperture hybrid phased array, with individual per element receive path low noise amplifiers delivering a noise figure cited at 3 dB, similar to an AESA. The antenna is constructed using phase shifter and receiver 'stick' modules, a similar technology to early US AESAs."
Click to expand...

That noise figure is fairly close to apg-68 at 3.25 and less different then the noise gap between apg-68 and 66

IMG_6392.png
 
F-2 said:
That noise figure is fairly close to apg-68 at 3.25 and less different then the noise gap between apg-68 and 66
Click to expand...

You can't really compare it tho as the LNA for Bars and AESA are in the radiating elements. While APG-66 and 68 is kinda far back. The feed assembly and the path will increase that. It's similar scheme as AN/SPY-1.

The NF Specification is perhaps only the receiver without taking account of the antenna feeds.
 
A more historical question, from what i gather the indian Super-30 upgrade was initially (before 2014) supposed to have a russian radar described as an AESA variant of Bars. What radar do they refer to, was this ever presented somewhere, any pictures of it or brochures or anything else of importance? Was this really a Bars AESA, or perhaps they refer to a N-036 variant?
 
And really a neophite question, my understanding is that for modern AESAs the TRMs are either GaA or GaN, with China apparently moving to the next generation GaO TRMs (it matters being an EV and rare earths superpower). But what material is used for the emitter modules of PESAs such as Bars and Irbis, or for older ones like Zaslon, RBE2 etc.?
 
stealthflanker said:
You can't really compare it tho as the LNA for Bars and AESA are in the radiating elements. While APG-66 and 68 is kinda far back. The feed assembly and the path will increase that. It's similar scheme as AN/SPY-1.

The NF Specification is perhaps only the receiver without taking account of the antenna feeds.
Click to expand...
Somehow agree.
To suplement my post, some link, old known source.. this is second edition..

archive.org

Introduction To Airborne Radar : GEORGE W. STIMSON : Free Download, Borrow, and Streaming : Internet Archive

Introduction to Airborne Radar by G.B.Stimson
archive.org

Page 477, 478.., 488 ..
And adaptive theshold is on page.. sequentional detection..
archive.org

Introduction To Airborne Radar : GEORGE W. STIMSON : Free Download, Borrow, and Streaming : Internet Archive

Introduction to Airborne Radar by G.B.Stimson
archive.org

(BTW Such detection, was I think, introduced also in Zaslon.. )

According to APG-68, well, I heard that, in that design was low power amplifier, on back plate of array antena.. similar as in radar of Ammram.. all this is done to put this as close possible to "source".
By the way, nice data. Maybe to be put in F-16 thread..?
lancer21 said:
And really a neophite question, my understanding is that for modern AESAs the TRMs are either GaA or GaN, with China apparently moving to the next generation GaO TRMs (it matters being an EV and rare earths superpower). But what material is used for the emitter modules of PESAs such as Bars and Irbis, or for older ones like Zaslon, RBE2 etc.?
Click to expand...
It is TWT (like in the above APG-68) or Klystron. Both, are high voltage, vacume tubes.. those works as power amplifiers..
 
LukaszK said:
Somehow agree.
To suplement my post, some link, old known source.. this is second edition..

archive.org

Introduction To Airborne Radar : GEORGE W. STIMSON : Free Download, Borrow, and Streaming : Internet Archive

Introduction to Airborne Radar by G.B.Stimson
archive.org

Page 477, 478.., 488 ..
And adaptive theshold is on page.. sequentional detection..
archive.org

Introduction To Airborne Radar : GEORGE W. STIMSON : Free Download, Borrow, and Streaming : Internet Archive

Introduction to Airborne Radar by G.B.Stimson
archive.org

(BTW Such detection, was I think, introduced also in Zaslon.. )

According to APG-68, well, I heard that, in that design was low power amplifier, on back plate of array antena.. similar as in radar of Ammram.. all this is done to put this as close possible to "source".
By the way, nice data. Maybe to be put in F-16 thread..?

It is TWT (like in the above APG-68) or Klystron. Both, are high voltage, vacume tubes.. those works as power amplifiers..
Click to expand...

Thanks for you reply LukaszK, but i meant the material in each individual emitter element such as the 1800 elements in Irbis, not the Chelnok TWT.
According to this link, apparently the material is ferrite, do i understand it correctly, or is in some other material in the contemporary Bars/Irbis radars, since they are described as PESA/AESA hybrids?

Evolution of AESA Radar Technology

Explores the history of AESA radars and how continuing advances in MMIC materials and fabrication technologies, advancing packaging technology and exponential growth in digital circuits opens many possibilities for the future
www.microwavejournal.com
 
LukaszK said:
well, maybe this helps slightly, old, dead source , but technically enough:

https://www.ausairpower.net/APA-Flanker-Radars.html

There is described "difference" between traditional PESA and "hybrid PESA" used in late Flankers...

From description of BARS radar..:

"
The BARS is the most advanced radar developed by Russian industry during the 1990s. It is unusual in being designed with a hybrid array arrangement, the receive path using very similar technology to US and EU AESAs, with similar sensitivity and sidelobe performance, but using a Travelling Wave Tube and backplane waveguide feed for the transmit direction, a technology closest to the B-1B and early Rafale EA radars. As such the BARS is a transitional design sitting in between Passive ESAs (PESA) and contemporary AESAs. There is no doubt this design strategy reflected the unavailability to Russian designers of the Gallium Arsenide power transistors used in Western AESAs.

The baseline N011M radar uses a vertically polarised 0.9 metre diameter aperture hybrid phased array, with individual per element receive path low noise amplifiers delivering a noise figure cited at 3 dB, similar to an AESA. The antenna is constructed using phase shifter and receiver 'stick' modules, a similar technology to early US AESAs."
Some comment. Typical, classical PESA was made from single high power generator - like TWT (Klystron). The power was provided by set of waveguides (typically in planes) or optically (generally in ground systems..) to array of passive elements - phase shifters.
Those elements , (like ferrite phase shifters) are controlled electronically and changes phase of each emitted signal.

Signals from all radiating elements forms single beam that is send. Refected from objects... very very weak signal reaches back antenna. The same passive shifters, designed both for handling high power, now are used to shift received signal, with exactly the same phase shift. Next... signals, weak signals, from all array elements are passed and summed to the receiver. Here low power receiver, can finally gain signal and pass to further processing...

This arrangement, has many drawbacks. Array was usually heavy, and has other disadvantages (and advantages).
But from signal and efficiency point of view, this looks like: high power energy is transmitted... first time ,,, some amount of power is lost in wave-guide while on send ... Next ...other power is lost in passive shifters ... On receiving similar happens... very weak signal ... first goes pass by passive snifters, this reduce energy, but worse is that those elements have own noise which is somehow added to very weak signal... then waveguides (once again reduction and noise) and finally this very weak signal reaches to amplifier...
This impact sensitivity. "noise figure" of early PESA was higher than conventional plate arrays (for example +6dB or more comparing to other design).
Lower sensitivity, and losses of power impacts range, that might be lower than in conventional designs, with the same array size and transmitter power.

Of course PESA had other features those, can somehow mitigate above mentioned drawbacks, like:
- possible bigger antenna size in the same airframe - as array could be fixed.
This somehow mitigates decrease of range , as - at least when target is in front of antenna: as effective array area might be higher than in conventional designs...
But for higher angles from array axis, effective array area drops significantly and fast... ( cousins of angle ..). As the array size has tremendous impact on radar performance (gain an beam with) - advantages were rather only for targets in front of plane.

- scanning might be adaptive... with for example dual detection threshold.. usually it was possible to use lower threshold..
In classical design this would lead to high false alarms ratio... as noise ... incidentally might cross threshold.
So in conventional radars, this need to be set high enough to pass only strong signals , and limit false alarms.
But in PESA lower threshold might be used... once signal cross threshold... scanning might immediately stop at that position to check if this is true object or false positive. And it can stay at that position more time than in classical design - to collect more energy. (It can even do monopulse precise coordinate estimation.... if required)

But generally those drawbacks of PESA were very severe. Solution was (analog) AESA in which:
- low power microwave signal is passed from common source via low power wave guides to emitting elements. Here , low power phase shiftier could be applied. Moreover energy of each elements can be precisely and dynamically set. This form "tapering" function - which reduces emitted sidelobes. Finally low power signal to be emitted is amplified in local power transistor . And that is just directly behind emitting elements.. no power is wasted...
- on receive side - is similarly , but in reverse order... very weak signal is directly amplified by receiving, low power, low noise transistor, "just below" the array. NO additional noise is added... this initially gained signal is (either down converted to intermediate frequency, or not) passed via phase shiftier and wave-guides to next stages of receiver.. But as signal is initially gained... noise of other elements has almost no impact on sensitivity.. hence cited above "low noise factors of AESA"

(The next step is digital AESA - where signal to and from elements are passed in digital form... but this is just different story,,,)

Returning to BARS... and IRBIS ... they claimed that this is "hybrid" design. In emitting way - it seems to be very similar to classical PESA.. with all drawbacks... in loosing some energy... lower frequency agility and so on...
But on receiving path .. this looks like more like AESA (at least if we cite the above article). So with low power, low noise transistors just below array and so on. So it might have high sensitivity comparable to AESA. And as author claims... Russian decided on that design, causes they have no technology to produce array of GaAs power transistors. But at reciving part - this is like AESA... even with possibility applying tapering function to reduce sidelobes.

Of course both PESA and AESA design has the same "problem" with high angles targets... parameters of those arrays decreases for high of boresight angles... To mitigate that - cheek arrays are used (like in Su-57) or movable PESA/AESA arrays - like in Su-35 , Grippen or Typhoon...

And comparing Irbit to BARS... BARS was further development of late 80tees design using PESA technology, technology developing that time for N-014
They assembly BARS - developed and made mature design in 90tees. And having this mature design, and experience, after decade, having much more sophisticated components of early 00', just did step further - doing BARS again, but with much more modern elements... This results, as you mentioned , with double transmitter of much more energy, thinner and more nimble antenna, better ..everything...
Click to expand...
Is there any particular reason as to why an Irbis-E-like upgrade was never applied to The MiG-29? Obviously, there have been improvements in its radars over the years, but none like The Irbis-E, so might that be a result of a space issue in terms of not being able to fit a second twt into, well, such a new radar for The Fulcrum? I'm just curious.
 
lancer21 said:
Thanks for you reply LukaszK, but i meant the material in each individual emitter element such as the 1800 elements in Irbis, not the Chelnok TWT.
According to this link, apparently the material is ferrite, do i understand it correctly, or is in some other material in the contemporary Bars/Irbis radars, since they are described as PESA/AESA hybrids?

Evolution of AESA Radar Technology

Explores the history of AESA radars and how continuing advances in MMIC materials and fabrication technologies, advancing packaging technology and exponential growth in digital circuits opens many possibilities for the future
www.microwavejournal.com
Click to expand...


The ferrite is the material for the Phase shifters, which itself used to provide the electronic beamsteering. This is simplified "Transmit and Receive" Chain from something like AN/SPY-1 or Irbis/Bars.

Simplified Chain.png

Almost all Phased array radars are using phase shifters. For PESA it's usually implemented in Dual-Mode ferrite phase shifter like this.

The "Hybrid PESA" is called "Hybrid" in the first place is because the transmit path is just like conventional mechanically steered radar. while the receive part, there are that LNA Located within the radiating elements, Ahead of the antenna feed down to the duplexer and the Receiver (Rx). So basically the Hybrid PESA here have "2 stage" Receivers. One is the LNA for which to amplify and to compensate the loss from the signal travelling all the way to the "real" receiver for which the signal processing are taking place.

AESA Antenna also have phase shifters tho this one is implemented in Semiconductor instead of Ferrite.

1739467337827.jpeg

That phase shifter contains a ferrite rod/block which to basically slow down the EM wave and thus induce a phase change. Which controlled through BSC (Beam Steering Computer) Of the Array. After that phase shifter the antenna elements is just made like your usual Copper/Brass or Aluminum. Like look at this, this is array antenna for Russian PESA which as you can read.. it is made out of Aluminum.

Pesathingy.jpg


You can even see the phase shifters in the topmost post where the tweet on that YAK-130's Bars-130 radars are posted

Bars130.png

The Low Noise Amplifier part to amplify the incoming signal is somewhere behind the phase shifters.
 
stealthflanker said:
The ferrite is the material for the Phase shifters, which itself used to provide the electronic beamsteering. This is simplified "Transmit and Receive" Chain from something like AN/SPY-1 or Irbis/Bars.

View attachment 759356

Almost all Phased array radars are using phase shifters. For PESA it's usually implemented in Dual-Mode ferrite phase shifter like this.

The "Hybrid PESA" is called "Hybrid" in the first place is because the transmit path is just like conventional mechanically steered radar. while the receive part, there are that LNA Located within the radiating elements, Ahead of the antenna feed down to the duplexer and the Receiver (Rx). So basically the Hybrid PESA here have "2 stage" Receivers. One is the LNA for which to amplify and to compensate the loss from the signal travelling all the way to the "real" receiver for which the signal processing are taking place.

AESA Antenna also have phase shifters tho this one is implemented in Semiconductor instead of Ferrite.

View attachment 759365

That phase shifter contains a ferrite rod/block which to basically slow down the EM wave and thus induce a phase change. Which controlled through BSC (Beam Steering Computer) Of the Array. After that phase shifter the antenna elements is just made like your usual Copper/Brass or Aluminum. Like look at this, this is array antenna for Russian PESA which as you can read.. it is made out of Aluminum.

View attachment 759366


You can even see the phase shifters in the topmost post where the tweet on that YAK-130's Bars-130 radars are posted

View attachment 759367

The Low Noise Amplifier part to amplify the incoming signal is somewhere behind the phase shifters.
Click to expand...
Many thanks to your detailed explanation Stealthflanker, though as i'm hardly knowledgeable into the intricacies of radar design, much of it is wasted on me!

I have asked the question from the angle of the fact that apparently because among others the chaos of the 1990s Russia lagged behind in developing the manufacturing capacity for AESA GaA and GaN TRMs, hence sticking with the PESA design in Bars and Irbis. At present though, is there information whether the AESA N-036 uses GaA or more advanced GaN TRMs? And same question for the Zhuk-AM in MiG-35 really.
 
Joint Soviet Fighter said:
Is there any particular reason as to why an Irbis-E-like upgrade was never applied to The MiG-29?
Click to expand...

To answer that, you must look deep at Soviet era industries "division" Where each companies have their own "supporting environment".

MiG for example, the radars are built by NIIP Phazotron. Irbis in other hand is developed by NIIP Tikhomirov. Among those companies tehre might be common solution and cooperations (e.g MiG-31 and to some extent Su-27 and MiG-29) But MiG platform are exclusively Phazotron's playgrounds.

Unlike NIIP Tikhomirov however, Phazotron have their own "future" for MiG-29 platform, which as you can see they want AESA. Thus why RP-35 or now you know it as Zhuk-AE was born.
 
stealthflanker said:
To answer that, you must look deep at Soviet era industries "division" Where each companies have their own "supporting environment".

MiG for example, the radars are built by NIIP Phazotron. Irbis in other hand is developed by NIIP Tikhomirov. Among those companies tehre might be common solution and cooperations (e.g MiG-31 and to some extent Su-27 and MiG-29) But MiG platform are exclusively Phazotron's playgrounds.

Unlike NIIP Tikhomirov however, Phazotron have their own "future" for MiG-29 platform, which as you can see they want AESA. Thus why RP-35 or now you know it as Zhuk-AE was born.
Click to expand...
Thanks :).
 

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