WL-FlexDDS

Flexible Multi-Channel Phase-Coherent 1GSps Radio Frequency Source

  Datasheet
WL-FlexDDS Radio Frequency Generators

FlexDDS is a multi-channel phase-coherent Radio Frequency source. The design directly addresses the needs of experimental physicists who want to control all signal parameters in real-time from a computer. Initially, a series of actions (like changes in amplitude or frequency, start of frequency sweeps, etc.) is compiled into commands which are then transferred to the FlexDDS-Rack via a USB link. Each time a (real-time asynchronous) trigger input is activated, FlexDDS-Rack executes one or several commands and waits for the next trigger event. There is no limit to the number of successive commands as they are loaded continuously from the host computer.

One outstanding feature of FlexDDS is its defined and known phase relationship between channels. For example, two channels can easily be set up to produce a Radio Frequency output at the same frequency and with an equal phase (or specified phase offset). Slightly detuning the frequency of one channel will then linearly increase the phase difference between the two channels.

Main Applications

  • FlexDDS-Rack: 19" rack which integrates the computer interface and power supplies
  • The rack can hold up to 8 independent FlexDDS Radio Frequency generator slots and 1 frontpanel controller slot (FlexDDS-FPCtl)
  • FlexDDS: Radio Frequency generator slot module
  • FlexDDS-FPCtl: Slot module for reference clock and trigger.
This product is no longer recommended. A next generation multi-channel version called FlexDDS-NG with a flexible Ethernet interface has been released as well as a new dual-channel version called FlexDDS-NG DUAL.

Downloads

Datasheet
Date: 2021/2/22
Size: 409 KB
Programmer's Manual
Date: 2021/2/22
Size: 399 KB

Features

  • Multi-channel operation with precisely known and adjustable phase relationship between channels
  • Real-time control of all signal parameters
  • Phase-continuous frequency tuning
  • Computer interface (e.g. USB 2.0 link, optional RS-232)
  • New: PDCPU Add-On: Per-Slot processor with 32 ns cycle time and 8192 instruction deep memory for added flexibility and fast real-time control of DDS parameters.

Sample Output Waveforms

Click on each image for more details.

WL-FlexDDS Radio Frequency Generators output waveforms
WL-FlexDDS Radio Frequency Generators output waveforms
FlexDDS output generated with the high speed reconfiguration (PDCPU add-on) and one single DDS profile, no other features in use (no external gating, etc.). Amplitude and phase specified via "polar mode". First pulse has 180°, second pulse has reduced amplitude and 0°, fourth pulse is the shortest one possible.
Time scale: one box is 100 ns.
WL-FlexDDS Radio Frequency Generators output waveforms
WL-FlexDDS Radio Frequency Generators output waveforms
The narrow-band output spectrum shows very little phase noise. Certain vendors that don't show spectra, perform poorly in this respect.
WL-FlexDDS Radio Frequency Generators output waveforms
WL-FlexDDS Radio Frequency Generators output waveforms
FlexDDS output:
Hann shaped pulse using the RAM modulation feature with up to 1024 amplitude samples.
WL-FlexDDS Radio Frequency Generators output waveforms
WL-FlexDDS Radio Frequency Generators output waveforms
FlexDDS output: Hann shaped chirped pulse using the ramp generator to change the frequency while the amplitude is fed from the RAM modulation storage.
WL-FlexDDS Radio Frequency Generators output waveforms
WL-FlexDDS Radio Frequency Generators output waveforms
FlexDDS output:
Arbitrary pulse shape using the RAM modulation feature with up to 1024 amplitude samples. Any amplitude shape can be programmed.
WL-FlexDDS Radio Frequency Generators output waveforms
WL-FlexDDS Radio Frequency Generators output waveforms
FlexDDS output:
a series of frequecy sweeps; each one is triggered from the BNC trigger input. The sweep parameters are streamed from the host computer so any number of such sweeps can be generated in succession.