Chinese Radar Developments - KLJ series and others
- Thread starter indochina
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@Deino has already started counting the elements.
by78
General
Good luck with that. The image is likely deliberately grainy to not give away the count.
This year's national innovation prize list. Of interest is the 3rd item from the bottom: "三代半导体（氮化镓)". The team behind a "third generation semiconductor (Gallium Nitride/GaN)" is being recognized for their work.
IIRC what's the extent of Gallium Nitride on Chinese naval ships? I recall that Type 055s were running Gallium Nitride AESA.
I heard Li Jie claiming the Type 055 is using GaN modules. Information on use of naval ships is scant. But I would suspect the dual sided radars, one used in the Type 075 and the other on top of Test Ship 892 might be GaN, in order to reduce the power usage and cooling requirements, keep the radar light and the array thin enough to allow to be dual sided. GaN usage may not be confined on the search radars but also on the navigation radars --- GaN also used in civilian navigation radars --- and also on SATCOMs, datalinks and EW.
GaN is also used in 5G basestations like Huawei and ZTE and stuff. Also found in higher end LED flashlights and power chargers from China. China seems full of this stuff, societally looking at it as a vector to help reduce power usage and improve power efficiency.
You can buy non military grade GaN modules for your own radar prototyping from China starting at least $5000 a module equal to four elements per module.
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What I can't tell is if this is a 400W module or a 100W module with 25W per channel. If it's a 400W module, then, even with losses, the T/R module gives you a 200 kW - 300 kW radar based on how tightly you can pack them in, and even if it's treated as PESA with 2.5 db losses, you get extremely good GaN range. If it's a 100W module, on the other hand, if you treat it as a PESA it doesn't make sense because the peak power increase (50 kW) won't compensate for the 2.5 db losses (377 km range vs 0 dBsm using the Irbis-E as a baseline)
That's peak over 100W for each Tx channel but your duty cycle is only about 10%.
As a Ku-band this is more likely a satellite radar. Or maybe a missile seeker? But its civilian.
This one achieves 25W and 50W from a duty cycle of 25%. This can be for a fighter radar or a naval fire control radar, though the spec is likely for a civilian application.
This one is even more impressive, with 50W and 100W at 20% duty cycle. This one can be for a naval search radar, SAM search radar or AEW, but once again, specs here is for a civilian application.
This might be 50W at 25% duty.
This one is C-band, says military there, and is likely for either a PESA or mechanical radar.
S-band GaN amp for satellite, possibly for PESA or mechanical radar.
300W GaN amp.
I only want to point out from these examples, there is certainly and undeniable usage of GaN in radar equipment in China and by inclusion, the PLA. Which exact radars we don't know. Some of these amps are for PESAs and mechanical radars, so something that might look "low tech" having a parabolic dish for a radar or Yagi or a PESA, might be powered by a GaN amp instead of using traditional amps that use cathode ray tubes.
Bonus. I don't know which complete system this is for, but its is a GaN amp for drone jammer.
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None at all. GaN has a relatively high failure rate for transistor count compared to silicon, which prevents them from being used in highly dense wafers with millions of transistors. Quite the contrary, GaAs and GaN are used for high power uses in electronics such as amplifiers and power circuits which are of relatively simple in design, and has nothing to do with CPUs, SOCs, DSPs and so on which remain in silicon. SoCs used in AESA modules are relatively generic, nothing like you see on a smartphone. Circuits are sometimes made by boutique fabs owned by the defense industrial complex themselves, like Raytheon and Northrop Grumman. Other times, like what the Russians did, they build their AESA using generic chips available in the commercial market.
Military required chips tend to be built on older technologies. Smaller micron sizes tend to be affected by cosmic rays coming down from the sky --- the smaller the transistor, the more things happen when an electrically charged cosmic ray like a proton goes through the circuit. Old, obsolete fabs are retained by the military to build chips that can be used for satellites and high flying aircraft. Same goes for EMP and interference proofing.
Much of IoT doesn't depend on 7nm or even 14nm. These are for smartphones.
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