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A-50 radar over one megawatt peak power!?!

Unread postPosted: 05 Dec 2017, 15:27
by milosh
https://dokumen.tips/documents/s-2-russ ... onics.html

Shmel works in frequencies from 2 to 4 GHz, minimum peak power output is 1MW, and it is frequency agile from low PRF to high PRF.


I first didn't believe in that info but then in one russian documentary A-50 officer mentioned maximum power is couple of megawatts.

This is peak power of some aegis like radars if I remember right is it usual for AWACS to have such high peak power?

Re: A-50 radar over one megawatt peak power!?!

Unread postPosted: 05 Dec 2017, 23:10
by michaelemouse
The E-3's avionics require about 1MW: https://en.wikipedia.org/wiki/Boeing_E- ... y#Avionics

The Russians are probably also trying to compensate for less sophistication with more brute force. That seems to be a common aspects of their design philosophy.

Re: A-50 radar over one megawatt peak power!?!

Unread postPosted: 06 Dec 2017, 01:37
by stealthflanker
not a brute force at all it's just physics.

Remember that these radars be it AEGIS, E-3 and Shmel are in S-band. They have to operate at lower PRF compared to one operate in X-band thus low duty cycle (because too much PRF and you won't resolve range).

The one you need to actually look however when about to make calculations is duty cycle. For this kind of AEW radar you could expect duty cycle less than 10% maybe 2-3% operate in MTI (Moving Target Indication) mode. Thus the average power would be like 30 Kilowatt and this power that determine range, transmitter design and cooling capacity required by the radar.

and transmitter rated at Megawatt is easier to produce and cheap in low frequency.

Re: A-50 radar over one megawatt peak power!?!

Unread postPosted: 06 Dec 2017, 21:01
by michaelemouse
Why the lower duty cycle in MTI mode? Is the duty cycle equally low in lookdown pulse-Doppler mode?


Low PRF and range: If you code the pulses to distinguish them, can you not increase range while being able to resolve range? If so, I presume that comes with disadvantages but I'm not sure what they are.

Re: A-50 radar over one megawatt peak power!?!

Unread postPosted: 07 Dec 2017, 21:49
by stealthflanker
michaelemouse wrote:Why the lower duty cycle in MTI mode? Is the duty cycle equally low in lookdown pulse-Doppler mode?


So you can do measure range by pulse delay ranging/unambiguous range. The pulse doppler mode might have kinda higher PRF though i don't know how much higher. but then it might need less accurate FM ranging to resolve range.



Low PRF and range: If you code the pulses to distinguish them, can you not increase range while being able to resolve range? If so, I presume that comes with disadvantages but I'm not sure what they are.


What do you mean ? Pulse compression ? it's to improve range resolution not resolving range.

Re: A-50 radar over one megawatt peak power!?!

Unread postPosted: 08 Dec 2017, 00:54
by michaelemouse
Sorry, typo: I meant: "can you not increase PRF while being able to resolve range?"

I was referring to FM ranging. Why is FM ranging less accurate than pulse delay ranging? Does FM ranging preclude Doppler filtering to pick out fast moving targets? Does it have other disadvantages?


Isn't radar typically quite good at range resolution? I thought angular resolution was usually much worse than range resolution.