It features, the company adds, greatly improved fixed point arithmetic and is aimed at applications in astronomy, physics and environmental measurements. While providing continuous real-time FFT at full sampling rate, this option also enables spectra accumulation capability, a key requirement for radio-astronomy. The image shows a radio astronomy signal capture; specifically, a “Solar burst with ‘tilted fibres’” observed with a 12-bit 12-bit PCIe digitizer plus FFT option, by Keysight Technologies, taken at the Radio Astronomy Observatory of ETH Zürich, Switzerland.
With DC up to 2 GHz bandwidth nominal, the card converts even low frequencies of around 0 Hz not observable with an AC front-end; moreover, AC coupling would introduce BF noise, whereas DC coupling provides measurement fidelity. By increasing the resolution from 8- to 12-bit, this option provides computation of a 32k points FFT for single or dual channels. Low-noise capabilities allow users to detect phenomena difficult to observe, such as tilted fibres (a phenomenon associated with flux lines in the sun’s corona) in a solar burst.
Additionally, in a controlled environment, this application can run at altitude of 15,000 feet.
Key features of the new FFT version include:
- Single and dual channel mode selectable on-the-fly
- High-speed FFT on 32,768 data values computed in 10.24 μsec at 3.2 Gsamples/sec
- Input bandwidth up to 1.4 GHz at 3.2 Gsamples/sec, resolution of 97.66 kHz per spectral line
- Highly improved fixed point arithmetic that eliminates deteriorating effects
Key advanced functionalities include:
- Sideband separation for I/Q mixers with full amplitude and phase error correction
- High number of accumulations: greater than 1,000,000 power spectra
- No dead time in the accumulation process
- Filter bank extension for superior channel separation without any drawbacks
"Thanks to a remarkable dynamic range, this new fast Fourier transform version allows performance of sensitive observations in highly interfered environment," said C. Monstein, Radio Engineer at Institute for Astronomy, ETH