News and New Products

Signal analyzers outshine spectrum-analyzer cousins

By Dan Strassberg, Contributing Technical Editor -- EDN, 9/28/2009

Agilent named its new N9000A CXA and N9030A PXA series of RF-measurement and -analysis instruments “signal analyzers” because the company believes the units target a wider niche than do swept-frequency spectrum analyzers. The low-cost N9000A CXA has bandwidths as high as 7.5 GHz, and the high-performance N9030A PXA has bandwidths as high as 26.5-GHz. They offer an array of built-in and optional capabilities that enable them to also perform many tasks that have become critical in testing and evaluating today’s complex, digitally modulated communications signals. Both series are part of the manufacturer’s larger X-Series, which also includes the EXA and MXA series. The X-Series spans instruments, measurements, and software and provides a consistent framework for signal analysis.

 The CXA series’ 3- and 7.5-GHz units, whose US base prices range from $12,657 to approximately $16,360, target general-purpose electronics manufacturing, low-cost R&D, and RF education, for which they provide flexibility through built-in and optional measurement capabilities that you can easily reconfigure. The PXA series’ architecture supports new measurement applications; future hardware add-ons; wider analysis bandwidths; and possible upgrades to the instrument CPU, memory, disk drives, and I/O ports. The series’ models cover frequency ranges of 3 to 3.6, 8.4, 13.6, and 26.5 GHz, and base prices range from $51,900 to $66,300.

 CXA analyzers offer built-in one-button measurements and optional advanced-measurement applications, including preconfigured test routines for noise figure, phase noise, and analog demodulation. To ensure consistency, the applications are virtually identical to those that run on the EXA, MXA, and PXA analyzers. In addition, the manufacturer’s 89600 VSA (vector-signal-analysis) software can run inside the Windows-based instrument, providing advanced analysis of more than 50 demodulation formats. On the production line, the CXA is more than two times as fast as other low-cost analyzers. For example, the CXA can return a peak-search result in less than 5 msec and perform a remote sweep and transfer in less than 12 msec through IEEE 488. The units also include LAN and USB (Universal Serial Bus) 2.0 interfaces. Switching between measurement modes typically takes less than 75 msec. The CXA series offers ±0.5-dB absolute amplitude accuracy, 13-dBm TOI (third-order intermodulation), −157-dBm DANL (displayed average-noise level), and 65-dB-WCDMA (wideband-code-division-multiple-access) ACLR (adjacent-channel-leakage-power-ratio) dynamic range.

 PXA units reduce measurement uncertainty and reveal new levels of signal detail, starting with spurious-free dynamic range as great as 75 dB with 140-MHz analysis bandwidth. Other specifications include −128-dBc/Hz phase noise at 1 GHz with 10-kHz offset, 0.19-dB absolute amplitude inaccuracy, and −172-dBm DANL-based sensitivity at 2 GHz, with preamplifier and noise-floor-extension technology. Like the CXA series, the PXA series offers built-in one-button measurements, optional advanced-measurement applications, and compatibility with other X-Series analyzers and with the manufacturer’s 89600 VSA software, which can run inside the instrument.

 For those looking to easily refresh or replace their test systems, the PXA is a form, fit, and function replacement for several popular spectrum analyzers, including the HP 8566 and 8568; HP/Agilent 856x; and Agilent PSA units whose bandwidth extends to 26.5 GHz. Key features include code compatibility; emulation of remote-programming language; default settings, timings, and couplings; arbitrary and second-IF output; fast-rise-time logarithmic-video output; and Y-axis output. You can purchase the MathWorks’ Matlab data-analysis software directly from Agilent as an option on all X-Series signal analyzers. These packages enable you to make application-specific measurements and test-modulation schemes and to develop your own customized applications using live signal-analyzer data.