From: OCTAD-S: digital fast Fourier transform spectrometers by FPGA
Spectrometer | 4G4K | 2G64K |
RF input | 4 | 2 |
ADC sample speed | 4.096 GHz | 2.048 GHz |
Observation bandwidth | 2.048 GHz | 1.024 GHz |
ADC resolution | 10 bit | |
ENOB | 8 bit | |
GFDR | ~38 dB | ~37 dB |
Max. input power | 0 dBm | |
Max. input frequency | ~8 GHz | |
FPGA | Xilinx Virtex-7 (XC7VX485T) | |
No. of FPGA per RF input | 1 | 2 |
Frequency channel | 2048 | 32,768 |
Channel separation | 1 MHz | 31.25 kHz |
Spectral resolution (−3 dB) | 2.0 MHz | 64 kHz |
Spectral resolution (−10 dB) | 2.9 MHz | 90 kHz |
Acquisition time per spectrum | 1 µs | 32 µs |
Spectral dump time | 8 ms | |
Number of accumulation | 8000 | 250 |
FFT resolution | 32 bit | |
Accumulator resolution | 45 bit | 40 bit |
Output resolution | 16 bit | |
Temperature range | 0–90 °C | |
Allan variance | >1500 s |