RoadTest: Tektronix RSA306 USB Spectrum Analyzer
Evaluation Type: Independent Products
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: MDO3104
What were the biggest problems encountered?: No trigger out, only trigger in
I get a little bit of time, so I will write what I learned during this period about RSA306. First thing I must say is big thanks for element14 community for roadtest program, as well as Tektronix for participating in this program. Is one of the best programs for normal people to get hands on new equipment, and explore new possibilities. As always with work, you need correct tools to get it done, and in some areas RSA306 fits that niche, by being affordable, relatively high performance, small size, and with basically unlimited functionality (since it is USB instrument, it’s all about software).
When I was applying to this roadtest, I targeted my vacation after exam season in university, so I could do cool stuff, like painting batman in frequency domain, and do other things, but shipping was delayed up until my vacations was over, and I started to work in new job, as well as still have to get master degree in university, so free time now is luxury I don’t have. So my goal for now is to write basic review, and expand it with time, since I have few ideas and projects where I need spectrum analyzer, like EMI compliance testing at my work, reflections and other transmitter/receiver circuit optimization, laser Carrier-Envelope Phase measurement and stabilization, and so on.
Computer with USB 3.0
In order to do roadtest for everybody, Tektronix supplied quite good and small computer. Since it’s need lot of processing, and high speed communication, they selected Lenovo ThinkPad E431 with touch screen, SSD, and what is most important Intel Core i7 with 4 hardware and 8 hyper threads. That means it can process lot of data in real time. By the time I turn it on, warranty was over, and it looks like RSA306 programs was installed 1 year ago. Since I do lot of programing, 3D and PCB designing, for Christmas I get new MSI GE-60 OE computer, that is many times powerful, and I will use it with RSA306
Idea behind RSA306
Usually, when we buy measuring equipment, we pay quite a big part for hardware. Usually, hardware for measuring unit will be much more expensive than simple core i7 motherboard, because of engineering, programming, and so on. So what Tektronix did, is used typical spectrum analyzer fronted, a bit of data packing, and cypress USB3.0 communication chip. That means it is possible send all ADC data to computer (ADC takes filtered data from mixer, and power at that time is directly related to VCO frequency). As far as I know, cypress controller can work with 32b bus running at 100MHz and have 16 control signals, so in theory, it will be possible to send buffered ADC data to computer. I know that RSA306 use http://www.linear.com/product/LTC2261-14 ADC converter, that can work at 125MHz sample clock speed, and with small FPGA (Xilinx Spartan 6) do at least 2x parallelization, and we can transfer data directly from ADC. But you need good software to make it work. I did some testing with Visual Basic programming ans super speed development kit, I could get data at 400MBps ( yes, MB), but I could not process it, I would need to use low level language with multiple threads to do any useful work with data. ( that project end up using Altera MAX10 fpga to process image data since it will work faster than computer with zero jitter and high predictability). And because computer have all hardware to get data, process it, and display , save, and do other stuff, RSA306 is best spectrum analyzer for this range and performance in the market today. I did some testing against MDO3104, and RSA306 I much faster. I would say it is 5-10 times more faster than MDO. This is because processing is done on 3GHz x 4 hardware cores, so it is very hard to beat. Also, it should be done in simple integer calculation where processor is quite efficient. Here is video:
Next weekend we will go to hardware, functions.