PXIe-5842 VST with 54 GHz Frequency Extension Block Diagram

The PXIe-5842 VST with 54 GHz Frequency Extension is a vector signal transceiver instrument that comprises multiple PXI Express modules: the PXIe-5842, PXIe-5655 (×2), and PXIe-5543. Additionally, the PXIe-5842 VST with 54 GHz Frequency Extension uses the RMM-5585 remote measurement module for millimeter-wave frequency coverage.

The following block diagram represents the PXIe-5842 VST with 54 GHz Frequency Extension:



Note Some calibration-related routing paths and front panel connectors have been omitted from the illustration of the high-level block diagram for simplicity.

RMM-5585 Port Configuration

The RMM-5585 is a super-heterodyne converter with independent LOs for signal generation and analysis, with the option to use a common LO programmatically. The RMM-5585 includes two full-duplex direct RF ports. You can use the NI-RFSA and NI-RFSG drivers to perform, respectively, analysis and generation on these RF ports simultaneously.

The one-meter cables included with the PXIe-5842 VST with 54 GHz Frequency Extension that connect the RMM-5585 to the in-chassis PXI modules of the instrument allow the high-frequency ports to be positioned close to the DUT to minimize loss between the DUT and the test system. Additionally, the RF ports within the PXIe-5842 VST with 54 GHz Frequency Extension, which reside on the RMM-5585 and PXIe-5543 modules, have variable reference levels that support a wide range of power levels. Finally, the RMM-5585 and PXIe-5543 contain internal loopback paths at millimeter-wave and IF frequencies, respectively, to facilitate self-calibration and improve measurement performance.

Operation Across Frequency Range

The PXIe-5842 VST with 54 GHz Frequency Extension has a frequency range for signal generation and analysis of 200 MHz to 54 GHz. Different physical modules within the overall instrument provide different frequency coverage across that comprehensive range.

In the PXIe-5842 VST with 54 GHz Frequency Extension, the PXIe-5543 RF port switch conveys signals to and from the PXIe-5842 VST module to the two RF ports, RF IN/OUT 0/1, for frequency coverage of [200 MHz, 23 GHz). The RF IN/OUT PORTS of the RMM-5585 convey signals of [23 GHz, 54 GHz] for coverage into the millimeter wave range.

The direction for each of these ports—in or out for analysis or generation, respectively—is software-configurable. You can use one port for analysis and another for generation simultaneously.

RMM-5585 LO Operation

By default, the RMM-5585 uses separate LO signals, both of which are sourced from a single PXIe-5655 within the overall PXIe-5842 VST with 54 GHz Frequency Extension, for the upconverter and downconverter. The PXIe-5655 that sources this LO is referred to as LO1 and is associated in MAX. When using this default dual LO configuration, the RMM-5585 can also accommodate independent frequencies on both LO signals to support frequency division duplexing (FDD), which requires different uplink and downlink frequencies.

Additionally, you can use an optional shared LO configuration, in which a single LO from the associated PXIe-5655 is routed through a single port on the RMM-5585 to both RF ports. Using a shared LO can reduce phase noise for some measurements.

Local Oscillators

The PXIe-5842 VST with 54 GHz Frequency Extension contains two stages of local oscillators (LOs) for analyzing and generating RF signals.

  • LO2—Mixed within the leftmost PXIe-5655 with the I/Q signals from the PXIe-5842 module to analyze or generate an IF signals of frequency [50 MHz, 23 GHz). You can use this IF signal to analyze or generate RF signals from the RF IN/OUT bidirectional ports on the front panel of the PXIe-5543 module within the instrument.
  • LO1—The IF signal and LO1 from the rightmost PXIe-5655 mix within the RMM-5585 to analyze or generate RF signals of frequency [23 GHz, 54 GHz]. You can use this RF signal to analyze or generate RF signals from the RF IN/OUT bi-directional ports on the RMM-5585 front panel.