For more than the last 60 years, electronic test and measurement instruments have evolved significantly to address the challenges of both commercial and military sectors. Like others, instrumentation also continues to migrate from traditional analog to digital technologies. And as the digital revolution continues to pervade military systems, so does the software. Consequently, the role of software is gaining momentum in new types of automatic test systems (ATS) needed to test modern military communications, radar, electronic warfare systems, and other countermeasure systems. To provide greater flexibility and interoperability with the advantage of easier upgrade via software without changing hardware, software has begun to replace physical knobs and buttons on traditional bench-top instruments with graphical user interface (GUI) and software panels.

That transformation is evident in so-called modern synthetic instrumentation (SI), which synthesizes the stimulus and/or measurement functionality. As a result, the Department of Defense (DoD) is working closely with the instrument makers and defense contractors to exploit advances in test methodologies and technologies to develop interoperable ATS that will use software building blocks to perform test functions on electronic circuits and systems across all the services.

In order to give our readers a better handle on the latest developments and advancements on the SI front, while exploring key drivers of this technology, this issue of RF Design's Defense Electronics supplement has generated a special report written by freelance technical writer Gene Heftman. In addition, two invited articles on this emerging SI paradigm stress the support from leading test and measurement instrument makers.

In the special report on this subject, Heftman uncovers efforts to make SI a reality in the defense environment. By speaking to major supporters and proponents of SI in military applications, this report focuses on its acceptance status and progress made by leading test and measurement instrument makers. In doing so, it shows that the SI instruments are conceptually similar to software-defined radio (SDR), which again has been the brainchild of the military. And its Joint Tactical Radio System (JTRS) has been providing the main impetus to SDR since the mid-1990s. Besides giving a broader perspective on the SI, Heftman's report shows that DoD's next-generation ATS system, NxTest, will rely on synthetic instrumentation for lower costs, more flexibility, and interoperable test gear that spans the requirements of all military services.

Based on core hardware and software components, the second article in this issue demonstrates the concept and shows how to implement the common stimulus and measurement functions in software. Thus, this article “Synthetic Instrumentation: Contemporary Architectures & Applications (Part II)” by Peter Pragastis, Iqbal Sihra and Michael N. Granieri of Phase Matrix describes three different flavors or instantiations of contemporary architectures or three types of SI developers. These include generic/loosely coupled component architecture, integrated COTS architecture and DoD application-specific architecture. All of these contemporary architectures are extremely similar from a block diagram point of view and primarily differentiate themselves on development strategies employed, reduction to implementation and applications.

The last article titled “Synthetic Instruments in Automatic Test Systems” by John Stratton of Agilent Technologies, highlights the move toward SI ATS architecture. And it differs from traditional stand-alone units. Because it focuses on the possibility of achieving high-performance measurements in an SI framework, it emphasizes the role of flexibility of SI software to accommodate many different types of hardware. And it also presents trade offs and ATS system design challenges implementing an SI test system. The Agilent article argues that for synthetic instrument's concept to be optimally successful (with both reusable hardware and open software) the industry must agree upon a few standards. With this in mind, it concludes that LAN-based synthetic instruments offer the best compromise between cost, performance, size, and — most important — long life. Plus, via software upgrades, it promises to offer protection from obsolescense, while reducing total acquisition costs.