Agilent Measurement Journal - Issue 5 - 2008 - (Page 1)

Finding a New Path when Assumptions Break Down at gigahertz frequencies and beyond. One explanation is rooted in Fourier theory, which states that any waveform can be represented by a combination of sine waves of speciﬁc frequencies, amplitudes and phase relationships. As high-frequency digital signals travel through physical media, delays to the constituent frequencies produce phase shifts and waveform distortion. These can cause unexpected or unreliable operation in digital circuits designed for sharply deﬁned ones and zeroes. For digital signals that exhibit such “analog-like” behavior, signal integrity measurements and jitter measurements are two ways to identify, estimate, quantify, and troubleshoot problems in digital systems. Tools such as the simulators within advanced design applications also help developers predict and minimize these problems earlier in the design cycle. In chemical analysis, it’s easy to imagine today’s “microﬂuidic” instruments as containing miniaturized beakers, tubes and columns that handle volumes of less than one microliter. When channels and chambers are less than 100 micrometers wide, however, ﬂuids may behave in unexpected ways — and a process as seemingly simple as the mixing of ﬂuids can become very difﬁcult, or very easy. At the microscale, molecules diffuse quickly over small distances, and heating or cooling occurs very rapidly. If those molecules interact with the walls of a microﬂuidic chip, they tend to behave in ways not seen in the macroscopic world: Different rules take over and different physical properties dominate. Researchers from Agilent and elsewhere have gone far beyond macroscale assumptions to understand ﬂuid ﬂow, diffusion, heat transfer, surface interactions, and fabrication at the micro- and nanoscale. From that knowledge, we’ve created instruments such as the high-pressure nanoﬂow liquid chromatograph/mass spectrometer (LC/MS). These advanced systems provide sensitive and repeatable quantitative or qualitative analyses of nanoliter and picoliter samples. Flawed assumptions don’t have to be a dead end. As you push the envelope in your work, I encourage you to step back, check for “assumption breakdowns”— and look for new paths that lead to fresh, successful approaches. As we’ve learned at Agilent, sometimes it’s the fundamental stumbling block that leads to the most intriguing breakthrough. Darlene J.S. Solomon Chief Technology Ofﬁcer, Agilent Technologies Vice President, Agilent Laboratories E Every type of measurement is based on fundamental assumptions about natural laws and physical behavior. As we push the technological envelope, however, real physical phenomena often cause breakdowns in our assumptions. When this happens, we need new tools, techniques and measurements to characterize the unexpected behaviors. In digital electronics, for example, the square waves that provide clock signals and represent data bits become distorted Visit the Journal’s online version to listen to Darlene’s podcast interview at www.agilent.com/go/journal Interviewer: Frank Elsesser, eMarketing Manager, Agilent Technologies Agilent Measurement Journal 1 http://www.agilent.com/go/journal

Table of Contents Feed for the Digital Edition of Agilent Measurement Journal - Issue 5 - 2008

Agilent Measurement Journal Issue 5 Finding a New Path when Assumptions Break Down Contents Testing MIPI D-PHY Protocols Oscilloscope Firmware Update DNA Replication Joining the LTE/SAE Trial Initiative Testing Proteins Praise for DC Power Analyzer Scripting Features for AMDS Testing Hybrid PCBA Systems Improving the Gene Expression System Workflow Turning a “Good Enough” Test Strategy into One That’s Reliable, Repeatable and Traceable Understanding the Effects of Limited-Bandwidth Channels on Digital Data Signals Introducing the 3GPP LTE Downlink Validating the 26 Validating the Physical and Protocol Layers in DDR Memory Interfaces Understanding Total Jitter Measurements of Low Probabilities Using Behavioral-Model Simulation to Accurately Predict First-Order PLL Performance Creating Synchronous High-Frequency Sampling across Multiple Digitizers Overcoming the Challenges of Testing FlexRay Networks Understanding Operating Life and Repeatability of Electromechanical Switches and their Effect on Total Cost of Ownership Implementing Micro and Nano LC/MS Techniques for High Sensitivity Lipidomics Analysis

Agilent Measurement Journal - Issue 5 - 2008

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