Microwave Journal

TestBench: October 2009

Delivering Advanced Capabilities in a Low-cost Signal Analyzer

October 16, 2009

In the evaluation of RF communication signals and technologies, spectrum or signal analyzers are often the tool of choice for engineers in R&D and manufacturing. When selecting an analyzer, however, there has often been a direct link between price and capability: Lower price usually means less functionality and less flexibility.

Finding yet another way to innovate in signal analysis, Agilent Technologies is now bringing greater functionality and flexibility to a lower price point with its N9000A CXA signal analyzer (Figure 1). The two models of the CXA are versatile, low-cost tools that provide essential signal-characterization capabilities up to 3.0 or 7.5 GHz, respectively. These analyzers help accelerate product testing and development on multiple levels: cost reduction, throughput, design enhancement and more. The CXA is also an excellent tool for RF education.

Figure 1: The Agilent CXA signal analyzer offers high-end features in a low-cost instrument.

Exploring the CXA’s capabilities

The versatility of the CXA analyzers starts with built-in one-button measurements and grows with optional advanced measurement applications. The library of measurement applications includes preconfigured test routines for noise figure, phase noise, analog demodulation, EMI pre-compliance testing and more. To ensure measurement consistency, the applications are transportable across the Agilent X-Series signal analyzers—PXA, MXA, EXA and CXA. For greater flexibility, the Agilent 89600 vector signal analysis (VSA) software and MATLAB® from The MathWorks can run inside the CXA, providing advanced analysis of numerous signal standards and modulation formats.

For wireless communications, one essential set of built-in capabilities is the PowerSuite, which brings simplicity, accuracy and repeatability to measurements such as channel power, adjacent-channel power (ACP), occupied bandwidth and other standards-based parameters. More than 75 one-button setup routines or custom settings are included for specific power measurements.

Among the optional capabilities, an analog demodulation measurement application offers one-button analysis of AM, FM and PM signals, which are still used in commercial broadcasting, business radios and elsewhere. To enable faster analysis and troubleshooting, this application provides a simultaneous quad view of the RF spectrum, the AF spectrum, the demodulated waveform and FM demodulation metrics.

Manufacturers of commercial electronic devices may be interested in another optional capability: EMI pre-compliance testing. Even under the best of circumstances, successful compliance testing can be expensive and time consuming—and can be risky if postponed until late in the development process. Using low-cost pre-compliance analysis earlier in the development cycle can help avoid costly product redesigns and launch delays. The CXA’s EMI pre-compliance testing option offers detectors and bandwidths that are fully compliant with CISPR 16-1-1 (2007). Its “tune and listen” capability can help discriminate between the ambient environment and signals from the product under test.

For advanced analysis, the CXA is the only low-cost signal analyzer that supports both spectrum analysis and vector signal analysis (VSA) in a single tool. Users have a choice of either the Agilent 89601A VSA software or the 89601X VXA measurement application. This makes it possible to measure, demodulate, evaluate and troubleshoot the complex, time-varying behavior of digitally modulated signals with the low-cost CXA (up to 10-MHz analysis bandwidth).

Enabling seamless testing across the product lifecycle

The CXA is the low-cost member of the Agilent X-Series signal analyzers. Comprised of the PXA, MXA, EXA and CXA, the X-Series is an evolutionary approach to signal analysis that spans instruments, measurements and software. The X-Series also provides a consistent framework for signal analysis, enabling teams and their projects to move at a faster pace. This comes from the ability to share test code, measurement algorithms and a consistent user interface across multiple performance points.

Looking across the four X-Series signal analyzers, each model occupies a well-defined role (Figure 2). For example, the PXA is the flagship, providing the highest performance for demanding applications in aerospace, defense, commercial communications and more. The mid-performance MXA is designed to accelerate the transition from design to manufacturing to the marketplace. The economy-class EXA offers exceptional throughput for manufacturing, and helps lower the overall cost of test. The affordable CXA is a versatile tool for essential signal characterization in cost-sensitive manufacturing, design-enhancement and education applications. All share an open PC architecture, proven measurement algorithms and a straightforward, consistent user interface.

Figure 2: The Agilent X-Series signal analyzers now span from the affordable CXA to the high-performance PXA.

Although Agilent’s future-ready signal analyzers are central to the X-Series, two additional elements complete the picture: the industry’s broadest set of advanced measurement applications; and powerful analysis software. This combination of instruments, measurements and software defines a concept Agilent calls X-Series signal analysis. This approach provides the flexibility to address business and technical requirements across multiple products and programs—now and in the future.

The Agilent CXA shakes up the status quo in RF signal analysis by offering high-end features in a low-cost instrument. With the ability to run one-button PowerSuite functions, a library of measurement applications and Agilent VSA software, the CXA offers engineers a sophisticated toolset typically available only at a premium price. It also carries the benefits of Agilent’s X-Series signal analyzers, which enable seamless testing across the lifecycle of RF and microwave devices, subsystems and products.

MATLAB is a U.S. registered trademark of The MathWorks, Inc.