When Hewlett-Packard introduced the HP 8753 in 1986, RF designers finally had an automatic network vector analyzer to call their own. The 8753 followed its higher-frequency counterpart, the HP 8510, which was introduced in 1983. The 8510 combined the power of microprocessors with the world's most advanced microwave hardware, bringing new levels of accuracy and ease of use to network analysis. These same capabilities were extended to lower-frequency measurements by the 8753, which soon became the standard for network analysis throughout the world.
Now comes a breakthrough as significant as the 8510 and 8753—the Agilent (formerly Hewlett-Packard) PNA series of network vector analyzers (Fig. 1). Instruments in this series combine exceptionally fast sweep speeds and dynamic range, low trace noise, four measurement re-ceivers with direct access, and 9-GHz coverage. In addition, the analyzers incorporate Microsoft's Windows 2000 Professional Operating System.
This gives them the full power of network connectivity and the ability to em-ploy a variety of tools for automated tests, like COM/DCOM and programming languages, as well as Microsoft applications for the postprocessing of measurement data. Ease-of-use features include electronic calibration (ECal), online and context-sensitive help, and robust built-in tutorials and manuals.
Four mixer-based receivers provide a standard low-noise floor of −118 dBm (−133 dBm by direct access). They also feature TRL calibrations for fixture and wafer applications direct-receiver access. Options are available for configurable test-set domain applications.
Measurement challenges that manufacturers of RF products face today provide clear goals for instrument manufacturers. Greater accuracy, higher measurement speed, a powerful but simplified operator interface, and the ability to integrate fully into a networked corporate environment are all essential ingredients in the design of today's state-of-the-art instruments. The PNA series of analyzers was designed to meet just such needs for both R&D and production environments.
Sweep speed, for ex-ample, illustrates just how great an advance the Agilent PNA se-ries is over both of its predecessors and competitive instru-ments. Furthermore, it shows how the instruments in this series don't compromise measure-ment speed to achieve wide-dynamic range. Measurements re-quiring 100 dB of instrument-dynamic range can be made with a 35-kHz bandwidth, rather than the 1-kHz bandwidth of the Agilent 8753ES, thereby producing sweep speeds that are 16 times faster than those of the 8753.
For measurements that require 120 dB of dynamic range, the PNA series is 35 times faster than the 8753ES. Sweeps that take 43 seconds on the 8753ES only take 1.2 seconds on PNA instruments. By removing the front-panel RF jumpers to directly access the measurement receivers (bypassing the internal directional couplers), more than a 143-dB dynamic range can be achieved. This provides insight into a component's performance that before was simply unavailable.
With a 35-kHz IF bandwidth, the PNA series can sweep six times faster than the 8753ES, updating a measurement 80 times per second. With a 10-Hz bandwidth, the PNA series achieves over 128 dB of dynamic range at the test-set ports, with an insignificant 0.0005-dB rms trace noise.
At a 10-Hz bandwidth using a reversed two-port coupler, the PNA series features a typical, average noise level of −147 dBc. This is much lower than the typical, −115-dBc average noise level of the older 8753 (Fig. 2).