New-Tech Europe Magazine | August 2016 | Digital edition

significant improvements in instrument performance simply by moving closed- loop control, measurement acceleration, real-time signal processing, or synchronous device under test control on the instrument itself. One application that software-designed instrumentation can uniquely solve is radar prototyping. In this application, customers can use the FPGA as a complete target simulator. In radar applications, a radar system detects a “target,” such as an automobile, airplane, or other object, by sending a stimulus signal and then waiting for the response. Attributes of the stimulus’ reflection off the target, such as the delay and frequency shift, indicate both the distance and velocity of the target. The combination of the VST’s wide bandwidth and user-programmable FPGA makes it ideal for target emulation. In addition, engineers can easily customize the FPGA to modify the types of targets they need to simulate. Part of a Platform One of the most important features of the VST is that it is part of a complete hardware and software platform. In the current era of smart, connected devices and ICs, modern test instrumentation has transitioned from discrete instruments to highly integrated test systems. As a result, meeting the latest measurement challenges like envelope tracking PA test and radar prototyping requires a platform of instruments that can be synchronized, customized, and easily controlled with software. Although the next wave of wireless technologies, from 5G to 802.11ax, will introduce significant design and test challenges, NI’s second-generation VST was created explicitly to address them. With wider bandwidth, a smaller form factor, excellent RF performance, and software customizability, the VST is scalable to meet the most difficult test challenges today and tomorrow.

Figure 4. Typical 8x8 MIMO System with 8 VSTs

Figure 5. Radar System Block Diagram with Custom mmWave Head

using existing instrumentation.

synchronization requirements. To test a MIMO device, RF test equipment must be capable of synchronizing multiple RF signal generators and analyzers. In these configurations, the instrument’s form factor and the synchronization mechanism are critical. Fortunately, the second-generation VST is small enough that engineers can synchronize up to eight VSTs in a single 18-slot PXI chassis with one slot dedicated to a PXI controller. Designed by Software A final requirement of next-generation wireless test systems is that engineers can design themwith software. Advanced wireless test applications increasingly require engineers to tailor the behavior of the instrument’s firmware. In these applications, engineers can experience

Modular and Easily Synchronized

Modern communications standards ranging from Wi-Fi to mobile use sophisticated multiantenna technology. In these systems, MIMO configurations provide a combination of either higher data rates through more spatial streams or more robust communications through beamforming. Because of these MIMO benefits, next-generation wireless technologies like 802.11ax, LTE- Advanced Pro, and 5G will use more complex MIMO schemes with up to 128 antennas on a single device. Not surprisingly, MIMO adds a lot of design and test complexity. It not only increases the number of ports on a device but also introduces multichannel

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