|Description:|| Prof. Dmytro Vavriv from the Institute of Radio Astronomy of the National Academy of Science of Ukraine (Kharkov) will visit ASTRON on October 27th for the purpose of an invited colloquium. |
In his presentation, he will talk about a recently developed digital receiver which is used at the Decameter radio telescope UTR-2, Kharkov, Ukraine. This receiver is shown in the figure above. It consists of two parts: an ADC module and a DSP board connected via a 5Gbit/sec serial data link. The DSP board is produced as a PCI card which supports the PCI-X64/66 standard interface. Different modes of signal processing are realized in the receiver by using the FPGA and the signal processor capabilities.
The ADC module is manufactured as a separate block in order to avoid interference from the DSP board and the PC. A high SFDR value of 115 dBc, a low noise floor of –120 dBFS, and a high SNR (dynamic range) of 74 dBFS have been achieved. A real time, half-overlapped FFT calculation and spectral averaging are carried out in the FPGA of the DSP board. The FFT is performed for 16384 points of a real signal (carrier) what provides 8192 frequency channels.
In addition to spectrum calculating modes, the DSP board can operate in a waveform mode. In this mode, it is possible to transfer data continuously with the rate of 260 Mbyte/sec via the PCI-X64/66 interface, and store them on the HDDs organized as a RAID-0 system.
The receiver has perfect linearity, a calibration option, and a capability for accurately computing correlations for beam-forming when used in multi-beam radio telescopes. Finally, the low cost of the receiver is determined by the usage of COTS components and original software solutions.
|Copyright:||Institute of Radio Astronomy of the National Academy of Sciences of Ukraine|