Chinese purchase of Su-35

Inst said:

Your arguments are just bad. You're doing a strawman argument because IRBIS-E is PESA, not AESA, when even the Russians have their own AESA technology. The advantage of AESA over PESA is that AESA tends to be more efficient; it loses less energy because its generating elements are inside each module, instead of connected to a central magnetron generating transmission losses. Likewise, because each module has its own emitter, its detection range scales better with aperture size than PESA systems.

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are the same electromagnetic waves or are not they?

is radar detection range voltage dependent? what does it mean power density?

why Irbis can have 400km for a square 3 meters target?

b787 said:

tell me what is the difference in the electromagnetic waves emitted by an AESA and a PESA? are they not the same Electromagnetic radiation?

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Actually they are not the same radio waves. PESA has only one transmitter therefore it can only emit a single radio wave at a single frequence at a time. AESA has many transmitters that can emit multiple beams of radio waves at different frequences at the same time.

dingyibvs said:

Not sure if serious?

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perhaps this will help you to understand AESA and PESA have the same physics

SanWenYu said:

Actually they are not the same radio waves. PESA has only one transmitter therefore it can only emit a single radio wave at a single frequence at a time. AESA has many transmitters that can emit multiple beams of radio waves at different frequences at the same time.

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If you divide a flow of a river into two streams or in 5 or 6 do you get the same amount in each stream to the original river?

b787 said:

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If you divide a flow of a river into two streams or in 5 or 6 do you get the same amount in each stream to the original river?

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No I wasn't talking about the strength of radio waves. I was only pointing out that the biggest difference between PESA and AESA happens to be the way they emit radio waves.

And characteristic of radio waves is about not only strength but also frequency

Could the mods please step in here? B767 isn't helping in this case; he's trying to divert it to something technical very few of us are competent with, but it's sophistry.

Actually, if you search reputable sources AESA is considered to have weight savings over PESA, since PESA requires a large klystron or magentoron exciter. PESA mostly has advantages in the sphere of cost.

For AESA vs PESA; consider Kopp's analysis of the Russian ZHUK-AE.



The Zhuk-AE reports a 400 km detection range, which is probably a 3m^2 detection range. This is exactly the same performance as the Irbis-E PESA, but the Zhuk-AE does so at about 15 kw peak power, 25% less than the Irbis-E system.

Inst said:

Actually, if you search reputable sources AESA is considered to have weight savings over PESA, since PESA requires a large klystron or magentoron exciter. PESA mostly has advantages in the sphere of cost.

For AESA vs PESA; consider Kopp's analysis of the Russian ZHUK-AE.

.

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"However, it is important to note that forming too many different beams will also reduce radar range."

Do you understand that? it means in order to have the same range it needs to reduce the number of frequencies used, limiting multitasking.

Plus price is not the same, so AESA limits is multitasking capabilities by reducing range at the expense of higher price, if you want to give the same range in each frequency let us say 400km of range then power peak increases so the sources says
"offers cost, prime power consumption, size and weight savings, as shown in Fig. 3."

So use your brain, the extended range is if it uses a single frequency in all T/R modules, once it does multitasking bye bye same range thus you need more power.

As and Interceptor IRBIS has still advantages over AESA radars, it has disadvantages too, but is not like you want to portrait.

Yes, both AESA and PESA are capable of forming multiple beams. The main gain in AESA over PESA is higher efficiency and lower weight; as I've shown you, you require 33% more energy to obtain the same range with Russian AESA vs PESA.

Comparing Russian PESA to American AESA, the difference becomes even greater. The APG-77 is rumored to have a 400 km detection range vs 1m^2 with 20 watt modules. This adds up to 40 kw (doubtful), which according to the radar energy equation should give you 19% more range. Removing the difference, you get a requirement of 50% more energy needed with Russian PESA.

Inst said:

Yes, both AESA and PESA are capable of forming multiple beams. .

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>>> Moderator comment: Condescending comment removed <<<

AESA are more efficient if only they focus on a single frequency, on a single frequency they offer advantages at a higher price, but if you commit to use the T/R modules into different frequencies the range in each frequency will reduce, so the AESA is limited in terms of multitasking.
PESA radars over extend the radiation losing so accuracy due to a single emitter, but by dividing the power in different frequencies range is reduced too.

So you are fantasizing if you think AESA is supreme, it is not, has advantages but not supremacy.

IRBIS is older technology, but by focusing its energy has a 400 km range for a 3 square meters target, not bad since it has enough power to over range many AESA systems[/COLOR]