The ETH Zurich FFT Radio spectrometer ARGOS Christian Monstein;
ETH Zuerich, Switzerland.
We report about our latest project, the FFT radio spectrometer ARGOS which is based on a commercial available high-speed sampler (SC240-like) from Acqiris company in Geneva Switzerland. This sampler is directly linked to a FPGA Xilinx Virtex-2 pro XC2V70 on the same PCB. The combination of a high-speed sampler and a FPGA is connected to a standard PC via a PCI-interface. The chosen standard PC is running under Windows XP, while the control software is written in Borland C++ Builder. A short presentation will be given about our system concept, schematic bloc diagram, cost and schedule.
Overall System Specifications
Input data:
- AD conversion 2 AD Converter, each with 1 GS/s, interlaced
- Input sampling rate fs = 2 x 8 x 133 = 2.128 GS/s
- Input data stream 2 streams even and odd samples, 1.064 GS/s each
- Input data resolution 8 Bit (24dB in voltage = 48dB in power spectrum)
- Input Bandwidth ~1000 MHz (fsampling / 2)
DFT:
- Number of DFT points 32'768
- Number of usable frequency channels 16'384 (in the range 0 ... fs/2)
- Channel spacing 64.49 kHz (at full sampling rate)
- Conversion time 15.398 us
- DFT overlap none
- Data and coefficient width max. 18 bits
Averaging:
- Minimum averaging 1 ms/ 64 values
FPGA:
- FPGA data input 2 ports, even and odd samples; 2 x 16 word parallel
Data output PCI interface, 64 Bit, 66 MHz
- FPGA main clock 133 MHz (twice PCI clock)
- FPGA Xilinx Virtex 2 Pro: XC2VP70
For more (but preliminary) information, have a look at: http://www.astro.phys.ethz.ch/instrument/argos/argos_nf.html