IN Brief:
- NI confirms a new four-port PXIe-5633 vector network analyser configuration for multiport S-parameter measurements.
- Software updates to the PXIe-5860 vector signal transceiver support synchronised multichannel and MIMO test workflows.
- An older NI brochure describes a two-port predecessor; no unconfirmed four-port frequency or dynamic-range specifications are used.
Emerson has expanded the radio frequency measurement capabilities of its NI PXI platform with a four-port vector network analyser configuration and software improvements for synchronised multichannel testing. The development combines new capabilities associated with the NI PXIe-5633 network analyser and the PXIe-5860 vector signal transceiver, targeting wireless devices containing multiple signal paths, antennas and transceiver channels.
Four-port measurement on the newly announced PXIe-5633 configuration allows engineers to characterise interactions between several RF connections in one VNA arrangement. A vector network analyser measures how radio frequency signals behave as they pass through or are reflected by an electronic device, providing information used to characterise filters, amplifiers, couplers and antenna networks. The instrument records both magnitude and phase, making it possible to calculate the scattering parameters, or S-parameters, describing electrical behaviour.
Multiport RF components can exhibit insertion loss, reflected signals and unintended coupling between connections, all of which influence the transmitted signal. Characterising these effects requires controlled stimulus and response measurements across relevant port pairs, with calibration accounting for errors introduced by the test equipment.
A four-port VNA can characterise transmission and reflection across more port combinations than a two-port instrument without repeatedly changing the connection arrangement. The complete set of S-parameters describes how signals applied at each port affect those observed at the others, including reflection and transmission behaviour. This is useful when characterising components or assemblies in which several electrical paths must operate together within specified limits.
The network analysis capability is accompanied by software enhancements to the NI PXIe-5860 vector signal transceiver, which generates and analyses modulated radio frequency signals. Whereas a VNA characterises network properties of a device, a vector signal transceiver can reproduce and measure digitally modulated signals associated with wireless communications. These approaches assess different aspects of device behaviour, and complex RF development often requires both.
Emerson’s software changes focus on synchronisation across multiple transceiver channels, supporting multiple-input multiple-output (MIMO) configurations and timing-sensitive applications. MIMO systems transmit and receive signals through several antenna paths, allowing radio equipment to exploit spatial separation, channel characteristics and signal processing. Accurate testing depends on controlling the timing and phase relationships between measurement channels because uncontrolled differences can distort observed behaviour.
Reliable MIMO channel alignment depends on reference clocks, triggering, signal path delays and calibrated timing relationships. Software can coordinate those functions, but the accuracy achieved still depends on the specific transceiver hardware, wiring and operating limits.
Within the NI PXI architecture, network analysis and vector signal transceiver functions can be used for S-parameter characterisation and modulated RF measurements through a common RF connection. Emerson says the arrangement can reduce the need for separate instruments and configuration changes when switching between measurements. A suitable automated sequence must still manage calibration, switching behaviour and reproducible test conditions.
An automated sequence can combine network characterisation and modulated RF measurements while retaining the relationship between device configuration, calibration and recorded results. A development laboratory may need to characterise the passive electrical response of a path before examining its performance with modulated signals. Keeping measurements within the same environment helps preserve the relationship between test conditions, device configuration and recorded results, although the relevant calibration procedures remain necessary.
The new capabilities are intended for semiconductor validation, advanced wireless research, aerospace and defence electronics, and other applications involving distributed or multichannel RF architectures. Emerson is demonstrating technology in a 4×4 MIMO configuration at European Microwave Week, combining the PXIe-5860 with four-port network analysis. The demonstration shows measurement functions operating within a common platform, rather than establishing performance figures for every possible system configuration.
Modular PXI systems allow instruments to be selected according to required measurement functions, with software providing a common interface for control and automation. That arrangement can help laboratories reuse test sequences and integrate measurements into production validation, although physical interfaces, bandwidth, calibration and timing capabilities must match the device under test. More RF connections also demand appropriate fixture design and consistent electrical paths.
The four-port PXIe-5633 adds further network measurement paths, while separate PXIe-5860 changes address synchronisation across transceiver channels. Laboratories specifying a particular configuration must establish its operating range, calibration options and available hardware features against the exact model being supplied, rather than transferring assumptions from earlier two-port variants. Both developments broaden the measurements that can be coordinated within a modular PXI test system.
