The RF output signal takes the following path from the PXIe-5841 FPGA to the RF OUT front panel connector.

  1. The I and Q digital signals are sent to the baseband digital-to-analog (DAC) converter through a LabVIEW FPGA I/O node after being written from the host.
  2. The DAC converts the digital I and Q waveforms into analog I and Q signals at 1,250 MS/s. Internal to the DAC, the output is two times interpolated to 2,500 MS/s.
  3. Based on the specified center frequency, the analog I and Q signals are conditioned and passed either to the direct conversion modulator high frequency path, or sent directly to the low frequency path for additional level control.
  4. Depending on the selection of high frequency path or low frequency path, the converted RF frequency is further attenuated or amplified based on the specified output power settings.
  5. The conditioned RF output signal is transmitted from the PXIe-5841RF OUT front panel connector through a frequency selective diplexer stage.