1 GHz of instantaneous bandwidth
From next-generation wireless technologies like 5G and 802.11ax to advanced aerospace and defense applications like radar test and spectrum monitoring, the demand for wider signal bandwidth to achieve higher peak data rates is growing. Leveraging fast sampling, high-linearity digital-to-analog converters (DACs) and analog-to-digital converters (ADCs), and wideband internal calibration mechanisms, the mmWave VST offers 1 GHz of instantaneous RF bandwidth with excellent measurement accuracy.
Figure 6. The mmWave VST offers 1 GHz of instantaneous RF bandwidth with excellent measurement accuracy.
With the high instantaneous bandwidth and calibrated front ends of NI VSTs, you can effectively deploy them for demanding applications such as radar target simulation, multicarrier aggregation, digital predistortion (DPD) algorithm implementations, 5G prototyping, and real-time spectrum analysis. Additionally, mmWave VSTs incorporate patented algorithms for amplitude and phase correction for high absolute amplitude accuracy and low deviation from linear phase across the span of their wide instantaneous bandwidth.?
Error vector magnitude measurement performance
The VST uses advanced, patented IQ calibration techniques to deliver best-in-class error vector magnitude (EVM) performance for wideband signals. A critical component of next-generation wireless devices is even more stringent EVM performance requirements over increasing bandwidths. With higher order modulation schemes and wideband multicarrier signal configurations, the RF front ends of today’s wireless devices require better linearity and phase noise to deliver the required modulation performance. Consequently, test instrumentation for wireless device test must deliver even more accurate RF performance.
If you have demanding EVM performance requirements, the modular design of PXI instruments provides you with the ability to improve on the VST’s native performance even further. Using the PXI external local oscillator (LO), you can achieve EVM performance better than -40 dB with your systems based on the mmWave VST.
The modular mmWave VST architecture and the PXI platform together provide synchronization and scaling capabilities for multichannel measurements that require phase coherence. You can achieve nanosecond synchronization between two mmWave VSTs out of the box for applications like dual polarization antenna over-the-air test:
Figure 7. Dual polarization antenna over-the-air test
You can extend the same level of synchronization to multiple input, multiple output (MIMO) test systems. The modern communications standards, such as 802.11ax, LTE Advanced Pro, and 5G, are using MIMO schemes for many antennas on a single device to provide a combination of either higher data rates through more spatial streams or more robust communications through beamforming. Not surprisingly, MIMO technology adds significant design and test complexity. It not only increases the number of ports on a device but also introduces multichannel synchronization requirements. With the compact footprint of the PXI mmWave VST, you can synchronize up to three PXIe-5831 VSTs in a single 18-slot PXI chassis. You can further expand your systems using MXI to integrate additional chassis as one PXI system.
Figure 8. Engineers can synchronize PXIe-5831s in a single 18-slot PXI chassis.
Like a single instrument, you can synchronize each VST in a completely phase-coherent manner. In hardware, a VST can import or export the LO so that all modules can share a common LO. In software, you can use NI’s patented T-Clock (T-Clk) technology to easily synchronize multiple instruments using the NI T-Clk API.