Until now, measuring the nonlinear behavior of RF components was not easy. And there were no scattering or S parameter equivalent for the nonlinear region. While S-parameters were developed as a method to analyze and model the linear behavior of RF devices, they have limitations and are defined only for small-signal linear systems.
To tackle this problem, researchers at Agilent Technologies have developed X parameters. Unlike S-parameters, X-parameters represent and analyze the nonlinear behavior of RF components in a much more robust and complete manner, said Chad Gillease, senior application engineer for Agilent’s Component Test Division, Electronic Measurements Group. As an extension of S-parameters under large-signal operating conditions, they are driven into saturation (the real-world operating environment for many components) and then measured under these conditions, added Gillease. When making this measurement, no knowledge is used or required concerning the internal circuitry of the DUT. Rather, the measurement is a stimulus response model of the voltage waves. In other words, he continued, the absolute amplitude and cross frequency relative phase of the fundamental, and all related harmonics, are accurately measured and represented by X-parameters.
The Agilent has launched Non linear Vector Network Analyzer(NVNA). According to them this is the most innovative work done by Agilent in 25 years .(Co developed by CTD & HFTC)
NVNA consist of Network Analyzer+ phase reference circuit +Application software and calibration (Mag & phase) + ADS simulation application with X parameter measurement application.
The X parameters come from PHD that is Poly harmonic distortion framework.
The X parameters can be imported to Computer in the MDIF format.
Where you can do HB & Envelop detection analyais, no transient analysis.
You can make your own models using this X parameters.
The new NVNA offers the ability to measure the calibrated amplitude and cross-frequency relative phase of measured spectra from 10 MHz to 26.5 GHz. Component characterization is enabled by measuring and displaying both the amplitude and phase of the full spectra -- fundamental, harmonics and cross-frequency products -- in the familiar and powerful PNA-X network analyzer. As a result, engineers are now able to better understand and more deterministically control the nonlinear behavior of their device under test (DUT), asserted Agilent. Data can be displayed in time, frequency, power or user-defined custom domains, providing additional insight into the nonlinear behavior of their components.
The NVNA also provides a nonlinear pulse-envelope domain measurement, which enables researchers to gain a deeper understanding of the memory effects exhibited by their devices by displaying the harmonic pulse envelopes. Both the amplitude and phase of the pulse can be displayed in the time domain, which shows the changes over time.
According to Agilent, the new NVNA options for the N5242A PNA-X microwave network analyzer are available now. Option pricing starts at $56,000.
Source:
Agilent.com
RF design.com
2 comments:
its nice artical......:-)
Cool, keep it up man.
Sadegh
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