Keysight Technologies, Inc. has  introduced an improved version of the FFT option, now available on the U5303A PCIe 12-bit high-speed data acquisition card. This card features two channels and a sampling rate from 1 GS/s to 3.2 GS/s.

Designed for astronomy, physics applications and environmental measurements requiring frequency domain signal processing, the card allows observation of phenomena never observed before with previous instruments making it a big step forward in terms of linearity, dynamic range and spurious free dynamic range (SFDR) measurements. While providing continuous real-time FFT at full sampling rate, this option also enables spectra accumulation capability, a key requirement for radio-astronomy.

With DC up to 2 GHz bandwidth nominal, the card allows users to convert 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. As a result of its low-noise capabilities, the card allows users to detect phenomena difficult to observe, such as tilted fibers in 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 μs at 3.2 GS/s
• Input bandwidth up to 1.4 GHz at 3.2 GS/s, 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

 

This application option comes with a dedicated FFT spectrometer graphic user interface, allowing fast initial start-up, display and export of the acquired FFT data.

Keysight 

keysight.com