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MWJ T&M Survey 2009: Agilent

Agilent responds to questions from Microwave Journal editors about the state of RF testing and measurement equipment today.

Responses by Carla Feldman, Agilent Wireless Business Unit marketing manager

MWJ - What’s your most significant new product/technology and how is it impacting how engineers work?

Agilent- Agilent introduces many significant new products each year and it is difficult to identify any single one based on the large number of markets we participate in.

One example is the DSO/DSA 90000A family of oscilloscopes introduced in early 2008. These products bring industry-leading noise performance along with the first ever 1 GByte deep memory to a family of high performance oscilloscopes having bandwidths from 2.5 to 13 GHz. They are indispensable core tools for customers working on a wide variety of designs, and together with the 25 application packages that are available constitute a very significant offering for Agilent. Their features and ease of use deliver productivity gains, and their raw performance helps enable the customers’ designs to be possible in the first place.

Another example is Agilent’s Nonlinear Vector Network Analysis software, for use with the PNA-X microwave network analyzer. It provides all the power, flexibility and measurement capability of the PNA-X for linear measurements but can easily switch into the NVNA mode for nonlinear measurements. The 802.16 standard on which Mobile WiMAX is based specifies a tight Error Vector Magnitude (EVM) requirement (-31 dB, based on a 1% packet error rate). Meeting this target requires that all system blocks be more linear and phase noise be considerably better than in an 802.11 design. Power amplifiers must also be more linear and boast higher efficiency. The key to developing linear active devices for LTE or Mobile WiMAX-based systems is to first characterize the nonlinear behaviors—those which do not have a linear input/output relation and are a major contributor to information interference and the reduction in effective bandwidth. Agilent recently introduced new Nonlinear Vector Network Analysis capability features a breakthrough in X-parameters (new, nonlinear scattering parameters), now allows engineers to quickly and accurately design and develop linear components and subsystems by removing the trial and error loops.

MWJ - What new technologies such as MIMO, LTE or DigRF are impacting the requirements for test equipment and how?

Agilent- There is no doubt that both 3GPP LTE and WiMAX have, and will continue to have, a significant and lasting impact on the communications industry in 2009. R&D spending in LTE, for example, has already begun ramping up from chipset development to components and integrated hardware. The same can be said of the technologies that go into making an LTE system work such as MIMO and DigRF V4—the latest version of the DigRF electronics interface standard for the cellular market.

While LTE and WiMAX will continue to dominate the industry as “killer apps” in 2009, at Agilent we also see the emergence of femtocells and other technologies getting traction.. Femtocells are small cellular base stations generally designed for use in residential or small business environments. As service providers work to establish the mobile device as the home’s central communication device, deployment of femtocells will likely garner increasing attention for their ability to help increase home coverage and cell site offloading.

If we specifically look at the complexity of MIMO technology, ensuring its optimal operation requires the engineer to accurately test the MIMO receiver—a challenging task given the large combination of variables that must be tested in a given MIMO configuration. A critical part of testing a MIMO receiver is replicating real-world conditions and channels and performing real-time fading of MIMO signals. Agilent’s PXB MIMO Receiver Tester provides up to 4 baseband generators, 8 faders, 120-MHz bandwidth, custom MIMO correlation settings, and supports testing and troubleshooting of 2x2, 2x4, and 4x2 MIMO. Signal Studio signal creation software runs in the instrument and provides the engineer with up-to-date standards-compliant signal creation. The Agilent PXB is a recent advance in MIMO receiver testing which marries the signal source, noise source and fader together in a fully-integrated, solution to successfully accomplish these tasks. Rather than offering signal generation only, as is the case with most current solutions, this measurement approach offers an exceptionally versatile platform for testing LTE and WiMAX receivers. It not only allows the engineer to replicate real-world MIMO conditions and channels, but also to generate realistic fading scenarios including path and channel correlations.

While LTE, WiMAX and even femtocells present an exciting opportunity, they also result in complex measurement challenges which must be addressed. Agilent currently offers a wide breadth of industry-leading LTE and WiMAX test solutions. Agilent is working to develop new measurement solutions alongside new technology development and commercialization. By taking this approach, Agilent is able to support the measurement needs of engineers designing innovation solutions for the future.

With regard to DigRF, Agilent recently introduced the industry's first Digital Radio Frequency (DigRF) V4 test solution. It enables comprehensive stimulus and analysis for developers of radio-frequency integrated circuits (RF-IC) and baseband ICs (BB-IC) as well as integrators of wireless handsets. "Cross-domain" test, such as DigRF V4, offers new insights that reach from individual digital bits all the way through to IQ-modulated RF signals. Agilent's test solution allows engineers to work in the domain (digital or RF) and abstraction level (physical or protocol layers) of their choice to quickly characterize RF-ICs and rapidly solve cross-domain integration problems.

MWJ - How is technology improving the capabilities of test equipment?

Agilent- Many of the same technologies that drive the need for new measurement solutions for our customers are also used by Agilent in the design of our latest test and measurement products. For example the trend from parallel to serial buses in order to achieve higher system throughput is embodied in our latest oscilloscope products, which use multiple serial data lanes to transmit data from the A/D converters to the memory management system. The continued developments in ASIC technologies are routinely capitalized upon in creating our products. And advancements in simulation technologies are used by our engineers in designing our equipment. Besides allowing us to create our solutions, the fact that we are using the new technologies ourselves enables us to directly identify with the key challenges facing our customers.

MWJ - What’s the importance of speed in test today? Can you give examples of where speed is critical and what sets the standard today?

Agilent- Speed and low cost solutions are important in today’s field test capabilities. Agilent’s new FieldFox handheld RF analyzer -- the world's most integrated handheld instrument for wireless network installation and maintenance (I&M). FieldFox improves RF field engineers' and technicians' productivity to perform base station I&M more efficiently and accurately. The Agilent FieldFox handheld RF analyzer is the first and only RF tool for base station I&M that is calibration-ready at the test port. It combines multiple RF measurement capabilities in one rugged, compact and lightweight package and can tackle complex wireless networks with test times that are more than 50 percent faster than traditional testers.

Another example is Agilent’s recently introduced N9340B handheld RF spectrum analyzer. This HD Radio measurement application is the lowest-cost In-Band-On-Channel (IBOC) solution on the market with one-button auto tune and channel list functions. It supports NRSC-5 spectral emission limit masks and includes features that enable fast and easy test. It is ideal for technicians and test engineers performing measurements on HD Radio signals. A key benefit of Agilent's HD Radio measurement application is a one-button auto tune function that calculates the appropriate reference level and center frequency following the recommended guidelines from Nation Radio Systems Committees, saving significant measurement time. Overall, this measurement application ensures fast and simple operation and offers significant time savings. In addition, this is the lowest-cost handheld IBOC measurement solution on the market.

Each of these examples demonstrates a customer expectation in field test of fast accurate measurements in a lower cost product that is easy to use and requires minimal set-up and maintenance. This ultimately reduces service monitoring and maintenance cost.

MWJ - How is accuracy a concern these days? More so than in the past? Does the market expect the same or better accuracy and speed for less money? If so, is this being addressed?

Agilent- Accuracy has always been important for test equipment, because by definition the test instrument provides the reference against which other circuits and systems are compared. The rule of thumb is that has been used in measurement equipment was that it needs to be ~10x more accurate then the parameter that you are trying to measure. So as electronics have become sophisticated and modulation formats more complex, the T&M equipment used to verify performance has had to keep up. Agilent Labs and its related Technical Solutions Operations are continually looking for the next solutions for the advanced designs that go into our equipment.

Agilent has always been committed to the best metrology and we continue to address this challenge through core research as well as product-specific innovations in our divisions. For example, our work on the IEEE 1588 standard for time-synchronizing multiple instruments represents a significant advancement that benefits the entire test and measurement industry and its customers.

And accuracy is of course is subject to the general trend of customers expecting more for less over time. Beyond this, there are some factors that are driving the need for more accuracy. One is that signals are getting smaller (in amplitude), faster (in frequency), and more complex (in modulation). So to properly resolve the desired, subtle distinctions in the signals from errors, more accuracy is required. Another, related factor is that design margins are shrinking, as customers push the performance of their designs to the limits.

MWJ - Any recent developments in test as part of the design cycle, that is the link between measurement equipment and EDA?

Agilent- Simulation is becoming more and more critical, because of the difficulty of getting a design right through empirical iteration (test and revise) alone. Several factors are driving this: raw performance, which makes signals such as traditional digital waveforms much more analog-like, more integration, which “ups the ante” on getting design blocks such as ASICs and MCMs (multichip modules) right on the first turn, due to both NRE cost and signal accessibility issues, and smaller parts and more complex circuit boards, which make probing and manual prototyping much more difficult. For most products, the days of breadboarding designs with relatively easy to handle (and see!) through-hole components are long gone.

Agilent is well equipped to help our customers cope with this trend through our Advanced Design System tool. ADS includes advanced simulation algorithms as well as facilities for linking the design software to our test equipment so that actual measured results can be incorporated into the design environment. And increasingly our instruments allow design data from ADS to be included in the measurements they provide. For example, S-parameters may be incorporated into an oscilloscope measurement to de-embed (back out) the effects of a test fixture on the measured signal.

MWJ - What are some of the issues facing production and field testing?

Agilent- Today's manufacturer are faced with the challenge of getting their products to market ahead of the competition, while at the same time protecting profit potential and ensuring the shortest possible test times. By effectively optimizing test times by moving from call to non-call testing in the production line the manufacturer can achieve highly accurate and fast solutions that enables them to quickly and easily perform calibration and verification testing for their high-volume production lines.

The Agilent N7302A-2FP software leverages Agilent's experience and success in the WLAN and Bluetooth(r) manufacturing market, making it faster, more accurate and more stable than other commercially available offerings. Its measurement and test flexibility allows manufacturers to fully optimize their production lines.

The N7302A-2FP software is used primarily with the Agilent N8300A -- a one-box RF parametric test set that offers superior specification and fast test times. The test set is specifically designed for manufacturing and design engineers who need a standard-compliant 802.16e physical layer test tool for Mobile WiMAX(tm) Tx and Rx applications. The N7302A's companion solution, the N6301A Measurement Application, runs on the test set and ensures fast and accurate measurement analysis of Mobile WiMAX signals.

As mentioned earlier in question #5 Agilent’s new FieldFox handheld RF analyzer is an excellent example of providing a superior field testing capability for the demanding mobile communications market. The FieldFox capablities include cable and antenna test from 2 MHz to 4/6 GHz, spectrum analysis from 100 kHz to 4/6 GHz, vector network analysis, and true average power measurements. It is the only RF handheld tool for base station I&M that is calibration-ready at the test port. It combines multiple RF measurement capabilities in one rugged, compact and lightweight package and can tackle complex wireless networks with test times that are more than 50 percent faster than traditional testers.ensuring today's wireless service providers have the most productive test solutions to address complex network issues in the field.

MWJ - How frequently should a company consider updating test equipment and how are they addressing aging test solutions?

Agilent- They should consider updating their test equipement at the start of any major new design cycle, or at least every two years for long-lived products that are already in production. While the rate of change of test equipment varies by product category, in general the improvements are happening faster than many customers may realize. Due to the high pressures these customers face in reducing the time-to-market of their own products, they should consider the engineering productivity advantages that updated test equipment can bring. In many markets one or two months of TTM acceleration represents a significant competitive advantage. New equipment can also reduce costs in production, due to more efficient testing. Even software enhancements and new applications that run on existing equipment should be assessed, because companies like Agilent often improve the core capabilities of their hardware platforms over time in order to better meet customer needs.

In terms of aging test solutions, these can often be improved by moving to newer equipment, in both R&D and manufacturing. In the latter case, test software changes are often required, but Agilent has applications engineers and documentation that can help ease the task. In some cases dramatic improvements in test quality and speed allow these investments to pay back very quickly.

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