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Every year, RF technologies are integrated into more mission-critical systems for military, industrial, and commercial installations or products. As applications for RF equipment expand, the need for high-performing, portable test and measurement equipment also increases. Traditionally, testing complex RF systems in the field involved mobilizing rack-mount, laboratory-grade equipment. These testing operations incurred high monetary as well as opportunity costs. Valued laboratory test and measurement equipment also was unavailable at times, as it would be used by other departments. These factors pushed RF test and measurement equipment companies to offer scaled-down, portable solutions with specific or limited uses.

In recent years, the heightened integration of RF components has enabled substantial feature upgrades to RF portable test and measurement equipment (Fig. 1). These enhancements have led to correlations between laboratory-grade, rack-mount products and portable solutions. Additionally, the market is seeing new varieties of applications for these high-end instruments outside of the field. This is good news for engineers, researchers, or technicians looking for cost-effective and durable RF portable test and measurement equipment. When choosing one of these feature-dense devices, however, they now have a lot of factors to consider. The following types of RF portable test and measurement equipment are commonly bridging gaps between the lab and field: vector network analyzers (VNAs), spectrum analyzers, signal generators, and cable/antenna analyzers.

Portable Test & Measurement Equipment Provides Benchtop Performance, Fig. 1

Signal generators stimulate an RF medium, like a coaxial cable or waveguide, with an RF signal. This operation is commonly used to service/test RF installations and support development when a medium- to high-powered RF signal is needed. Some signal generators can produce modulated signals, mimicking telecommunications systems for advanced test. These instruments are defined by metrics like signal resolution, settling time, phase noise, power range/resolution, spectral purity, frequency range, and frequency switching speed. Many modern signal generators come with USB, GPIB, or Ethernet connectivity for automated control and integration with test environments. Hittite and AnaPico, for example, offer compact RF signal generators with internal battery options. They can serve as portable test and measurement equipment in optimal field conditions. Of course, there are more ruggedized, extreme-weather offerings for devices that are more likely to be used in servicing and troubleshooting situations, such as RF analyzers.

For their part, VNAs measure the magnitude and phase of the reflection and transmission of RF energy through a system. VNA measurements are used to characterize a device, component, or sub-assembly to determine if the unit is operating according to specification. The number of ports, frequency range/resolution, data points, measurement speed, error correction, and sensitivity/noise floor are usually the critical specifications for portable VNAs. Most portable VNAs have one or two test ports and come with a variety of upgradable options, such as the following: modules that enable time-domain analysis, remote control, rapid calibration, signal-analyzer features, USB power sensing, GPS localizing, DC voltage sourcing, power metering, pulse measurement, and distance domain measurement. Bird, Agilent, and Anritsu all offer ruggedized versions of portable VNAs with many optional upgrades (Fig. 2).

Portable Test & Measurement Equipment Provides Benchtop Performance, Fig. 2

Portable VNAs are similar to signal analyzers with a few key differences. Signal analyzers measure a device’s RF characteristics using communications specifications. Such specifications include amplitude, carrier level, phase noise, sidebands, bandwidth, and harmonics. These analyzers are most commonly used to measure unknown and uncharacterized signals for identification and classification. Demodulation and scalar measurement techniques aid in these measurements. According to Richard Duvall, Technical Marketing Manager for Tektronix,"Portable spectrum analyzers are best used in spectrum-management applications. Performing spectrum mapping and chasing down interference signal needs to be done quickly, and often involves drive tests where portability can be critical.”

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