The Moku:Pro has a switchable low-pass anti-aliasing filter on its analog paths. Understanding under which conditions each filter is engaged is critical to understanding your high frequency signal's properties.
The Moku:Pro can capture four input channels at 1.25 GSa/s, or a single channel at 5 GSa/s. The anti-aliasing filter is switched between 300 MHz or 600 MHz bandwidth (defined as the -3dB point). The conditions under which this happens, and the interaction between these, depends on the instrument.
The Oscilloscope acquires at 1.25 GSa/s with 300 MHz bandwidth by default. It will switch to 5 GSa/s and 600 MHz bandwidth if all of the following conditions are met:
- Only a single channel is enabled,
- That channel is set as the trigger source, AND
- The time span is set to 200ns or less.
Lock-In Amplifier, Spectrum Analyzer and Frequency Response Analyzer
These instruments don't require strong analog anti-aliasing protection due to their internal architecture. As such, they use the higher filter bandwidth at all times; they all run at 1.25 GSa/s and 600 MHz bandwidth.
Other instruments have internal decimation to reduce the sampling rate and bandwidth for processing, and the Moku:Pro prioritizes anti-aliasing protection. As such, they run at 1.25 GSa/s and 300 MHz bandwidth.
Multi-Instrument Mode always uses 1.25GSa/s and 300MHz bandwidth, regardless of the configured instruments.