QAM test equipment recommendations?

[biff44]

Anyone have experience testing components for QAM systems. I am doing a 64/256 QAM system at 6 GHz (30 MHz) and 11 ghz (10 MHz bandwidth) for OC3 data rates.

The obvious choices are:
Tektronics real time spectrum analyzer for testing receiver, AWG, like a 5012C, for testing receivers.

Agilent

R&S

National Instruments VSA with labview

Other?

What woud you recommend.
Testin of modulator FPGA, Demodulator FPGA, upconverters, filters, power amps, etc for EVM, Phase noise, BER, etc.

 

[BigBoss]

R&S designs and manufactures these "dedicated" test equipments.
Agilent might be a good choice but I'd prefer R&S..

 

[kalyanasv]

There are other non conventional choices: 1.) LeCroy 2.) Zodiac are two I know of off-hand.
I have used: Agilent (which is probably the most well known and most expensive)
R&S has a very good analog interface but their baseband is not as good as Agilent.
NI I haven't used

LeCroy they are cheaper, and their scope tools are not the best in market but for QAM testing it should be sufficient.

One more to the list of not so common that i remembered: Anritsu

 

[biff44]

Yes, cost is a big factor. I do not want to buy some gear for $150,000 when there might be adequate gear at some lesser known vendor for $20,000!

Also, I a very concerned about obselescence. There is a ton of used VSA gear on the market--all unusable because the poor processing bandwidths and memory are insufficient for modern modulaiton types. Who the heck was it that decided that 10 MHz of processing bandwidth would be adequate in these older systems???? I want something that will actually be useable 5 years from now.

 

[tony_lth]

Ambient temperature cycle equipments, such as from -40~+60 deg.
And you can buy some software, such as Carriecom IDU, then you don't need VSA, the software can do it for you.

 

[biff44]

Tony, I can not find anything about Carriecom on google. DO you have a link?

It seems like I should be able to just get a high speed data acquisition card, like and Agilent Acqiris (used at $1000), and some cheap software, and be able to do my own home-grown VSA. It is the software I can not find (other than spending a fortune on Agilent software, that probably would not work with older acquisition cards anyway)

I am really surprised that ALL of the older VSA units have such limited processing bandwidth! all the old agilent E4406, 85600, 89610, 89611, 89640, 89641,e2371b, e1439c,at2000, 8594, 89410, Keithly 2820, all the tektronix VSAs before the very latest real time spectrum analyzers--NONE of them can handle 125 MHz IF QAM at a 25 Msym/s rate!

Rich

 

[kalyanasv]

i think he is talking about: Carriercomml. I checked it out but looks more like a Defunct company..no updates since 2004! Nevertheless interesting. I presume the reasoning behind the low bandwidth would be design polyphase filters for all the bandwidths would a little expensive besides the symbol sync.
Agilent is almost market monopoly almost on the VSA....

 

[biff44]

Hey, Troy NY. 'tute?

 

[tony_lth]

Yes, Kalyanasv is right. You can contact them. I don't know why they don't update thier website since 2004, but I still use their IDU until April 2010.
In fact, maybe you need a IDU (Indoor unit) of microwave point-to-point telecomm. There are many companies that produce IDU, such as NEC, Remec, AllGon, etc.
The IDU have standard E1/STM1 interface for data ports, and the uplink can output 350M TX IF with 128QAM or 256QAM, and the downlink is 140M IF. The IDU embeded software can draw the constellation of 256 QAM, test BER etc for you.
And the IDU is very cheap, because of the mass production.

 

[kalyanasv]

biff44: @ the polytechnic

 

[biff44]

Tony, I am building my own 64 and 256 QAM ODU and IDU with "special features" I can not buy off the shelf. I need gear to test out the whole shebang.