SinoDefence Forum

lilzz

AESA (Active Electronic Steered Array)
At this point, the russia doesn't have that, they only have passive ones.
AESA enabling technology is based on Gallium Arsenide Microwave Monolithic Integrated Circuit (GaAs MMIC).
The Russia doesn't have that kind of IC fab.

China is starting to have Gallium Arsenide, but it's only the beginning. ANy
news on the any research for the AESA?

RedMercury

Russia does have it. An example is the Phazotron Zhuk-AE on the Mig 35.

lilzz

That's something I curious. The Russia 's semiconductor and electronics tech is behind China, and in general lacking behind western standard. Why is it capable of developing some of more capable defense tech.

Gollevainen

Becouse Russia had bit earlier start than china...You have remember that before the 90's when chinese modernisation program begun to pay fruit, it was technologically desperetly behind practically anyone else many reason. Soviets in the otherhand had benefitted in purely technically point of wiev from the race against its rival. In the period when China begun to rise rabidly, russian/soviets were in depression stage yet the infrastructure and know-how was still existing and in smaller spectrum the development went forfard.
China in otherhand has only started in the "major league" so it has still alot miles ahead before it can reach the level of the other players. Sofar the sighns are good...

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lilzz

For any type of modern radar system it must consists of the followings
Front-end RF IC in the AESA case, the GaAs ICs
Back-end Processing IC (CPU-like) DSP , FPGA ICs...
I think regardless any systems made by the west or Russia, there must exit those elements.

Granted, the russia has more experiences, but they must have those quite sophisticated Semiconductor ICs to do the job regardless. Do you know if they make their own or buy big quantity from the west, which I doubt both..
Basically, I like to how the russia get those ICs to do the job.

crobato

Russia is starting to have GaAs fabs (Sistema is their main telecom company and Mikron is the fab company). Still nothing like the way China has. China is one of the biggest producers of GaAs in the world, as a matter of fact, Chinese overproduction and dumping is one of the reasons why prices of GaAs dropped.

The main reason for GaAs is commercial; they are used for telecommunications like celphones. Every celphone has a GaAs MMIC. Not just celphones, but portable handsets. Besides that, LED screens like those use in laptops, monitors and flat screen TV also use them.

Chinese research into AESA started in the nineties and there was a number of research papers on that. An institute in Nanjing called NEDI is probably the one responsible for producing China's electronic scanning T/R module.

http://ieeexplore.ieee.org/xpl/freea...isnumber=16640

Some old stuff about NEDI that isn't in the net no more. You can find NEDI's official webpage and they also produce SAW devices, which is another very essential device for RF applications. One use of SAW device is pulse compression which is a kind of LPI technique. If you note some of the MMIC products here are in the military wave bands like X and Ku.


China produced its first GaAs MMIC back in 1980.

http://216.109.125.130/search/cache?...icp=1&.intl=us

25GaAs MMIC Activities in NEDINanbin YangNanjing Electronic Devices Institute524 E. Zhong Shan Road, Nanjing, 210016, ChinaAbstract:This paper reviews the principal activities of NEDI in the field of GaAs MMIC’s withthe emphasis on the fabrication technologies and products characteristics. It also describes some
highlights of NEDI MMIC development and key resources of NEDI MMIC work.Key Words: GaAs MMIC, MESFET, PHEMT, HBT, Fabrication technologiesI.

INTRODUCTION

Nanjing Electronic Devices Institute (NEDI), founded in 1958, is mainly engaged inmicroelectronics, optoelectronics and vaccum electronics. GaAs MMIC is the one of its most important fields on research, development and production with following highlights.

·Starting in 1978·First GaAs MMIC ( X band oscillator MMIC) in China in 1980·First paper on chinese GaAs MMIC reported on IEEE MTT-s International MicrowaveSymposium in 1981·
Own-designed and made Φ2” GaAs high pressure LEC crystal puller in 1983·First chineseΦ2” GaAs processing line in 1990·
First chineseΦ3” GaAs processing line with MMIC CAD center and heterojunction epitaxialmaterials laboratory in 1996·
Own-designed and madeΦ3”/4” GaAs high pressure LEC crystal puller in 1997·Over 150 prototypes and products of GaAs MMICII.
GaAsMMIC RESOURCESNEDI is possessed of many valuable resources for GaAs MMIC regarding the building, theequipment and instrument, the manpower as well as the technology.·Engineers: 65 (including professors and senior engineers)·Clean room: 1500m2(including 60m2class 10 photolithography area)·Materials: ΔHigh pressure LEC crystal pullers for Φ2”, 3”/4” GaAs ingot ΔMBE forΦ3” GaAs wafer ΔMOCVD for Φ2”, 3” 4” GaAs wafer·Design:ΔWorkstations: HP9000/700, SUN 10 ΔMicrowave devices ,circuits design andanalytical softwares: Ansoft, HP-EESOF, Compact Explore, GATES POSES,First Joint Symposium on Opto- and Microelectronic Devices and Circuits, April 10-15, 2000, Nanjing, China26MDS, ADS, IC-CAP, Cadence·Mask: ΔPattern generator ΔRepeater·Chip fabricationΔSteppers, G-line, I-line ΔDUV mask aligner ΔIR backside aligner Δtrack ΔPECVDsΔRIEs ΔSpray etcher ΔIon implantersΔRTA ΔEB evaperators ΔSputtering systems Δ Wafer lappingmachines ΔWafer polishing machines ΔDicing system
ΔWire bonding machines ΔDie bonding machines·DiagnosticsΔScanning electron microscope Δ1500 x optical microscopesΔEllipsometer ΔHall effect measurement systemΔC-V profiler ΔAlpha step film thickness meterΔStress measuring system·TestΔNetwork analyzers ΔSpectrum analyzersΔNoise analyzers ΔPower testersΔOn-wafer autoprobers ΔParametric testerIII.GaAsMMIC FABRICATION TECHNOLOGIESNEDI has successfully established 3 kinds of Φ3” GaAs fabrication technologies with somefeatures1.Ion implantation MESFET process·Forming a n active layer for the channel and a n+ Ωcontact layers for the sourceand drain by ion implantation·Rapid thermal annealing with a special dielectric encapsulation for increasing theactivation and improving the uniformity.·I-line stepper lithography to print 0.5μm gate·Si3N4passivation for power devices to obtain the breakdown voltage of larger than15V·Air bridge and backside via hole·Si3N4and Ta2O5MIM capacitors·Yield ≥90%·Power: 0.5W/mm(10W C band)2.MBE PHEMT, HFET PROCESS·Unique optical lithography method to realize 0.25μm T-shape gate structure·Double recess to obtain higher breakdown voltageFirst Joint Symposium on Opto- and Microelectronic Devices and Circuits, April 10-15, 2000, Nanjing, China27·Power: 1 W/mm (X band) and 300mW (34GHz)3.MOCVD HBT process·H+implantation for limiting the E—B junction area and realizing the device isolation as well asminimizing the device parasitic effect·Breakdown voltage of the power device can reach to 20V·Stepper lithography to print the E and B with the 0.5μm space between them·Air bridge with SiN passivation and backside via hale·SiN MIM capacitor·Power: 3W/mm (X band)4.Process control monitor (PCM) and statistical process control (SPC)
PCM and SPC are employed on the processing line to monitor the process parameters and
improve the yield.5.Processing capacity
250 wafets/weekIV.GaAs MMIC PROTOTYPES AND PRODUCTSA partial list of GaAs MMICs that NEDI has developed is given below·Power application: power amplifierdriver amplifier·Receiver use: low noise amplifier mixeroscillator/vcobuffer amplifier·Controlled circuits: switch (SPDT, DPDT) phase shifter (analog, digital)attenuator (analog, digital) limiter·Others: active filter active circulator·Frequency range: L to Ku bandSome typical GaAs MMIC prototypes and products with main characteristics are depicted asfollows.·S-band MMIC frequency-variable front-end receiverRF frequency: 2.0-2.5GHzIF frequency: 30-200MHzNF< 1.5dBGP50 ±0.5dBLO power <5dBm VSWR <1.5·C-band MMIC internally-matched power amplifierFrequency: 5.2-6.2GHz GP>11dBPout3w·X-Ku band MMIC power amplifierFrequency 9-13GHz GP13dBPout2w·2-6GHz MMIC power amplifierGP17dB Flatness ±1dB P-129-30dBmFirst Joint Symposium on Opto- and Microelectronic Devices and Circuits, April 10-15, 2000, Nanjing, China28·2-20GHz MMIC distributed power amplifierGP7.5 ±1dB Pout23dBm·MMIC family for T/R module use Frequency 9.3010.4GHzMMIC power amplifier: Po1-1.5w, GP15-20dBMMIC5 bit phase shifter: IL 9.5dB, VSWR 1.5Phase error (RMS) 3oMMIC SPDT switch: IL 1.5dB ISO 25dB·MMIC DPDT switch Frequency 870-970MHz IL 0.8dBISO 20dBVSWR < 1.2P-0.133dBm Control voltage 0,-3V

crobato

Now there are plenty of radio T/R and MMIC research papers in China and some of them turn up in yahoo or google search. Stuff like this tend to be dual use so its not clear where the boundary for military and civil projects lie.

There is another of projects that claim to be active radar and one of them is the SLC-2 which is an artillery spotting radar and can be used to detect and track low flying aircraft. An artillery spotting radar detects artillery shells, which is quite small and gives a very precise tracking of the shell which is used to locate where its origin, so you can direct your own batteries against it.

The radar on the 052C is said to be AESA, and although many believe its PESA, the extensive cooling equipment seen for this radar in the test ship 870 suggests this may be more of an AESA, since one of the drawbacks of AESA is the enormous heat.

Which brings us to the next issue. I don't think GaAs based AESA is the way of the future due to its power requirements and heat emissions. Despite the advantages of AESA, the great heat and power means the plane will be saddled with heavier supporting equipment even though the radar itself can be made lighter. This means more powerful and heavier transformers, which you cannot shortcut for weight since they depend on ferrite cores, as well as refrigeration.

It is better to leap the entire GaAs generation into GaN or Gallium Nitride, which uses less power and wastes less energy as heat. GaN also has very big potential applications in commerce in the telecom MMIC business and in the LCD flat screen business, and this is one field Chinese industries are also jumping aggressively headlong.

China's jump into AESA in some applications may be as a result of another deficiency. Unlike the Russians, the Chinese may have trouble producing TWTs (Traveling Wave Tubes) of enough size and power for large PESAs. (A TWT is something like a Klystron or Magnetron). So going into solid state T/R modules may be in fact be easier, though more expensive.

challenge

in there own admission,cost of single T/R MMIC is 6~7 times more expensive than US.price for will not start falling until 2010.