Technical Insights > RF + Microwave

Four Measurements for Field Engineers on the Go

2020-08-31  |  5 min read 

Field engineers and technicians have to perform a variety of RF and microwave tests in remote locations. In many cases, they don’t know which tests they need to perform until they reach the test site. This predicament leads to them carrying too much — or not enough — equipment with them. The challenge exists in deciding which tools to carry with them, and which to leave behind, often causing them to sacrifice capability for portability.

In order to combat this issue, field engineers opt to carry an all-in-one, handheld analyzer capable of performing multiple tests. This blog covers four popular tests that field engineers perform using all-in-one, portable analyzers so that they can test more with less equipment.

1. Real-Time Spectrum Analysis

RTSA processes signal samples gap-free and generates results that correspond to traditional spectrum analysis measurements. This type of measurement is especially useful when searching for an interfering signal that overlaps with your carrier signal. Because RTSA eliminates deadtime commonly seen in traditional spectrum analysis, you are more likely to identify and locate quickly pulsing signals interfering with your network, as shown in Figure 1.

Figure 1. An overlapping, interfering signal captured on Keysight’s FieldFox using RTSA mode

2. Noise Figure

A communication system’s performance relies on its signal-to-noise ratio. Noise figure measures the degradation of the signal-to-noise ratio as a signal passes through an active or passive device. Lower noise figure values typically mean better device performance. Handheld analyzers capable of performing noise figure measurements, like that shown in Figure 2, enable field engineers to quickly characterize system components and optimize designs in the most cost-effective manner.

Figure 2. Noise figure measurements made using a FieldFox handheld analyzer
Figure 2. Noise figure measurements made using a FieldFox handheld analyzer

3. Cable and Antenna Test (CAT)

Harsh weather conditions frequently cause maintenance issues and failure in exposed cable system transmission lines. Because transmission lines are often very long, end-to-end measurements are impossible. CAT measurements solve this issue by identifying the locations of poorly performing adapters, antennas, and cable lines. Measurements like distance-to-fault (DTF), shown in Figure 3, and time-domain reflectometry (TDR) help to locate and characterize the types of faults in transmission lines so that field engineers know the types of problems occurring in their system.

Figure 3. DTF and TDR measurements of a transmission line captured on a FieldFox handheld analyzer
Figure 3. DTF and TDR measurements of a transmission line captured on a FieldFox handheld analyzer

4. Over-the-Air (OTA) Testing

OTA measurements assess the level of cell coverage needed to ensure continuous connectivity in various mobile communication scenarios like voice, text, and data. Field engineers use OTA antenna testing to verify and troubleshoot network handovers and analyze beam performance. This type of measurement is especially useful for operators verifying coverage for users shifting between LTE and 5G. Figure 4 depicts OTA demodulation of 5G cells and their respective powers.

Figure 4. OTA demodulation of 5G cells captured on Keysight’s FieldFox


Installing and maintaining cellular networks, satellite ground stations, radio networks, and other communications systems requires in-field verification and adjustment of components. With more than twenty measurement applications, Keysight designed FieldFox to perform the measurements that field engineers need so that you never have to sacrifice instrument capability for portability. Keysight also offers you the convenience and flexibility to upgrade your FieldFox handheld analyzer with user-installable license keys. When you need additional measurement capabilities added to your unit, there is no need to send your analyzer back to Keysight for upgrades.

To find out more about the measurements discussed in this blog, download the white paper “Four Measurements You Can Perform on the Go”.