Santa Clara, Calif.—If you are doing sophisticated RF/microwave design, development, characterization, and evaluation, then X-parameters (not the same as S-parameters) provide deep insight into performance and specifications of networks and components. A series of Nonlinear Vector Network Analyzers (NVNA) units from Agilent Technologies Inc extends the range of their PNA-X family of instruments to 13.5, 26.5, 43.5, and 50 GHz and also adds new measurement and analysis features.
Figure 1: Agilent PNA "X Nonlinear Network Analyzer (NVNA)
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In addition, they mesh resultant data with modeling, simulation, and design tools such as their Advanced Design System (ADS), to enable accurate nonlinear simulation under arbitrary matching conditions, thus allowing prediction of component behavior in complex, nonlinear circuits. Depending on the range of the instrument you use, corresponding likely applications include radar, satellite, and defense systems; wireless communications systems; base stations, and on-wafer device testing.
The instruments enable for single-connection, multiple measurements for CW (continuous wave) and pulsed S-parameter, compression, IMD, and noise figure. They include two built-in signal sources, simplifying test rack setup. These sources offer high output power (+16 dBm) along with harmonics below -60 dBc and a 40 dB power sweep range.
Figure 2: X-Parameter Analysis on Agilent PNA-X Nonlinear Network Analyzer
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Internal signal-routing switches provide additional flexibility for signal-conditioning hardware and additional test equipment. Further, there are internal pulse modulators and generators for pulse measurements, normally among the most complex parameters to instrument. This speeds test setup and measurement time by up to 30x, the vendor claims. For on-wafer device tests, the instruments eliminate the need for multiple stations, thus saving time, reducing probe contact with bonding pads, which leaves marks and degrades and even damages devices under test (reducing yield, as well).
Among the many analyses made possible by members of the PNA-X portfolio are vector (amplitude/phase)-corrected nonlinear measurements, including calibrated, absolute amplitude and relative phase (cross-frequency relative phase); vector-corrected bandwidth for time-domain waveforms of currents and voltages of the device under test (up to 50 GHz for the high-end model); multienvelope domain measurements of analysis of memory effects; and X-parameter extraction for use with nonlinear simulation and design in the ADS X-parameter block.
The sophistication of these instruments is seen in their price, which Agilent says is 30 to 50% cheaper than alternative available solutions, if they can do the job at all (the savings do not take into account time or rack/footprint savings). The N5241A (10 MHz to 13.5 GHz) PNA-X network analyzer is $76,500; at the other end, the N5245A (10 MHz to 50 GHz) unit is $140,000.—Bill Schweber
For more information, contact Agilent Technologies, http://www.www.agilent.com or go to http://agilent.com/find/pna-x, which also has background on nonlinear vector network analysis.