Agile RF Synthesizer (ARF/XRF)

The MOGLabs ARF and XRF RF synthesizers are priced to stop you building your own, bullet-proof so you don't have to be frightened of turning it on, and incredibly agile to meet the needs of quantum ion and BEC research. And it has MOGLabs ergonomics, so you can use it as a simple self-contained AOM driver, or as an optical noise eater with analogue input and built-in PID feedback.

The device provides two channels of agile RF frequency synthesis with optional high-power RF amplifiers built-in. Each channel spans a frequency range of 20 – 400MHz with output power up to 4 watts (+36dBm). The two channels can be used as simple manually controllable AOM drivers via front panel knobs to adjust frequency and output power, simultaneous FM and AM (or PM) modulation with 10MHz bandwidth, and servo feedback built-in for laser noise-eating or frequency locking.

The computer interface (10/100 ethernet and USB) allows full control of all parameters, including loading of FM, AM and PM data for triggered or looped playback. Fast frequency chirps or complex waveforms can be defined with 0.23Hz, 0.2mW and 0.4mrad (0.02°) in time intervals as short as 16 ns (XRF). 16 digital input/output signals can be individually controlled in synchronisation with the DDS sequences.

The ARF and XRF use a fast FPGA to drive two AD9910 DDS cores. Communications are handled by two separate microcontrollers. FM, AM and PM sequences can be incredibly complex using interpolation, repeats, loops, ramps, and external triggers.

Example of simultaneous AM+FM

Autonomous table-mode execution

The ARF and XRF include "table mode" functionality for automated execution of instructions, such as generation of pulse sequences.

The ARF is capable of updating the amplitude, frequency and phase of the RF output at 1us intervals, and the XRF includes an additional "advanced" table mode that can update one parameter at 16ns intervals, allowing for smooth pulse shaping.

Example of simultaneous AM+FM

High-speed dual-parameter modulation

The ARF provides two analog inputs per channel for modulation (AM/FM/PM/PID).

Modulation of one parameter can be achieved with a -3dB bandwidth of 10MHz, and simultaneous modulation (e.g. AM+FM) can be achieved with an update-rate of the second parameter at 1MHz.

Demonstration of noise suppression by intensity stabilisation

PID intensity-stabilisation/noise-eating

The ARF features a built-in PID controller that can automatically adjust the RF amplitude to stabilise the intensity of a diffracted beam and suppress intensity fluctuations.

We provide instructions for setting up and optimising intensity-stabilisation experiment in our application notes.

Example of external TTL-controlled pulse generation

Fast TTL control and pulse generation

Each channel can be controlled from an external TTL input to switch the RF on and off in very short timeframes (<50ns from input to output). This enables rapid pulse generation

16-channel digital I/O control using XSMA board

16-channels of digital I/O

The FPGA within the ARF is interfaced with a 16-channel bank of digital I/O for interfacing with other devices. The outputs can be driven simultaneously from table mode, enabling the generation of complex pulse sequences or triggers for time-critical synchronisation.

The XSMA breakout board (pictured) provides convenient SMA connectors for interfacing with the many channels of the device.