Crafting the Next Generation of Entry-Level Network Analyzers

How Agilent Sculpted Its Latest Instrument Platform For Manufacturing Test

PALO ALTO, Calif., Jan. 12, 2004

Comparisons of the latest vector network analyzers invariably focus on performance parameters such as dynamic range, trace noise, and sweep speed. These are benchmarks that instrument manufacturers continuously strive to improve, yet a significant portion of the user community is interested in instruments that provide a well-rounded combination of performance, features, and low cost. In fact, estimates show that up to 40 percent of users are most interested in low-cost network analyzers that do not hover at the leading edge of performance, but simply provide basic S-parameter measurement capabilities and very good performance.

Agilent Technologies and Hewlett-Packard before it have long served this important market sector with network analyzers that are carefully crafted to provide the right combination of features and performance required in the manufacturing environment. As a result, the 8712 and 8714 instruments for applications below 3 GHz and 8720 and 8722 instruments for microwave and millimeter-wave applications have been the leaders in this area since their introduction in the early 1990s.

Obviously, technology has dramatically advanced since these instruments were designed, and buyers of lower-cost network analyzers today have more demanding needs - but must adhere to strict budgetary considerations. The challenge facing Agilent in designing its next generation of low-cost network analyzers was to ensure that these users would continue to have the measurement performance expected of a next-generation instrument, while maintaining prices at their current levels, or even less.

To achieve this, Agilent began with its ENA and PNA Series analyzers, the most advanced in its product line. The features essential to basic network analysis and manufacturing test were included and many of the core features of the ENA and PNA Series were retained. This engineering was conducted with customers' tight pricing constraints as a foremost consideration.

Fortunately, microprocessor, semiconductor, software, display, and storage technologies have provided a way to bring these goals to fruition, through their lower cost, higher levels of integration, and superior performance. The ENA-L and PNA-L instruments embody these advances, and the results are significant. For example, the ENA-L analyzers, while offering higher performance in virtually every area than the 8712/8714, are a third shorter instrument depth and half the weight. Measurement speed is nearly seven times faster, dynamic range is up to 15 dB greater, and other performance parameters are improved as well. Equally dramatic are the performance improvements of the PNA-L over the 8720 and 8722 instruments. Their sweep speed is up to 20 times faster, dynamic range is at least 5 dB greater, measurement points per trace 16,001 versus 1,601, and maximum IF bandwidth is 250 kHz versus 6 kHz.

Advances in electronics technology also allow functionality to be increased without raising cost. For example, the ENA-L offers four measurement channels (versus two in the previous instruments) and the PNA-L offers 32 (versus only two). The ENA-L has a color LCD display with optional touch-screen capability, versus a nine-inch monochrome CRT displays in the 8712/8714. The PNA-L can display up to 16 measurement windows simultaneously (versus four), and Ethernet and USB interfaces complement the GPIB interface. Both instruments support Agilent's ECal electronic calibration system through USB. The ENA-L and PNA-L are compared to both Agilent's previous lower-cost network analyzers and the high-performance versions (ENA and PNA) in Tables 1 and 2.

These capabilities allow Agilent to expand the range of its ENA and PNA Series instruments to embrace the needs of the large number of designers who need basic network analysis tools, with the highest available levels of performance in their class, at a much lower cost than state-of-the-art instruments.

ENA-L, ENA, and 8712/14 Compared

1. S-parameter test set, at 3 GHz
2. 201 points, 2-port calibration, 90 dB dynamic range

PNA-L, PNA, and 8720/22 Compared

1. 50 MHz to 20 GHz, 201 point, two-port calibration
2. Measurements taken at 20 GHz

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Contact:

Janet Smith, Agilent
+1 970 679 5397
janet_smith@agilent.com

Heather Van Schoiack
Weber Shandwick, for Agilent
+1 425 452 5457
hvanschoiack@webershandwick.com