Analog Angle Article

Agilent handheld VNA takes accuracy, portability, built-in calibration to the field

Santa Clara, CA–The days of field installation and test requiring just a voltmeter, oscilloscope, spectrum analyzer/TDR, or similar instrumentation are fading faster than a multipath-plagued channel between two moving nodes in an urban environment. Today's high-performance links require the use of vector network analyzers to adjust, assess, characterize, calibrate, and equalize channels. The N9923A handheld vector network analyzer (VNA) from Agilent Technologies addresses this reality by packing a high-performance instrument into a field-friendly 6-pound (2.8 kg) unit which runs for 3.5 hours on its internal rechargeable batteries.

(Click on image to enlarge)

But portability and run time are not the only requirements for field instruments. Temperature variations and consequent drift can corrupt an instrument's accuracy and resultant measurements, so this unit includes an optional “QuickCal”, an integral calibration subsystem (therefore, no external calibration kit or fixtures are required) with stability of 0.01 dB/°C; Agilent claims this is the first VNA to have such an internal calibration reference and function.

The N9923A provides full two-port error-corrected S-parameters (magnitude and phase), for cable and antenna test, distance to fault, return loss, and VSWR measurement. It can provide basic cable loss (a one-port measurement) as well as insertion loss and transmission measurement (two ports).The VNA, with its 6.5-inch (14.5 cm) transreflective display and backlit keys, provides the venerable Smith chart, as well as vector voltmeter function and even power readings using an external 24-GHz USB power sensor. To aid multidimensional assessment of the field situation, the display can show up to four images and parameters simultaneously.

Trace noise for the unit is under 0.01 dB rms, and directivity is greater than 42 dB. Internal storage starts at 16 MB, for rendition of up to 1000 traces. External storage and I/O includes one microSD card slot and two USB 2.0 ports, and there is also a mini-USB port and LAN connector.

Dynamic range for the instrument is over 100 dB, and the completely enclosed unit (no fans, no vents) is weather resistant with large keypad buttons (Agilent said that a touch screen, while “cool”, was determined to be unreliable under the field-use conditions). It is MIL PRF 28899 Class 2 compliant; Agilent claims it is the only handheld network analyzer to be so. Operating range for the 11.5″ × 7.4″ × 2.8″ (2.92 × 1.88 × 7.2 cm) instrument is –10°C to +55°C.&#8211Bill Schweber

Pricing and availability : The Agilent N9923A, 4-GHz version, starts at $12,000; with the QuickCal option it is $14,500. It is available now.

For more information : contact Agilent Technologies Inc.,♦

0 comments on “Agilent handheld VNA takes accuracy, portability, built-in calibration to the field

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.