Portability provides flexibility in testing. At one time, that portability might have come with some tradeoffs in performance and capability compared to larger and heavier benchtop instruments. But modern portable RF/microwave test instruments can perform quite well in a laboratory, along with making on-site measurements in the field. In fact, companies on tight budgets can fill a great many measurement needs with a single portable instrument, such as a spectrum analyzer or a vector network analyzer (VNA).
One of the earliest portable RF/microwave test instruments, the model 492 spectrum analyzer from Tektronix, along with the firm’s 494 portable spectrum analyzer, essentially help build the company’s reputation for innovation and measurement quality. Although physically large, the 492 could be carried from place to place and operate well into the microwave frequency range. Used units working past 20 GHz are still sold on online equipment-sales sites.
Modern portable RF/microwave test instruments bring greater accuracy and measurement capability in packages that can be held at length in one hand (the 492 typically required two hands to carry). For example, Anritsu Co. manufactures various portable analyzers under its “Site Master” tag, for cable and antenna measurements, spectrum analysis, optical testing, even for passive intermodulation (PIM) testing (under its PIM Master product line). The popular Site Master model S820E cable and antenna analyzer can cover a frequency range as wide as 1 MHz to 40 GHz with as much as 110-dB dynamic range, and can be equipped with a VNA mode for measuring forward and reverse scattering (S) parameters as part of VNA measurements.
It can perform broadband and narrowband tests on components and systems from lower-frequency wireless applications through higher-frequency line-of-sight (LOS) links and satellite-communications (satcom) systems. For all of its measurement power, it can run for several hours on a rechargeable battery. Similarly, the KTN9918A FieldFox VNA from Keysight Technologies packs a number of RF/microwave measurement functions, including a VNA, spectrum analysis, and power measurements into a battery-powered, handheld package that extends from 30 kHz to 26.5 GHz.
The Site Master and FieldFox instruments are small and light in weight, but both instrument lines are constructed for durability and for use in demanding applications, including in defense system testing. At the very least, they provide several hours of operating time on one battery charge, and they are equipped with multiple data ports, such as local area network (LAN) and Universal Serial Bus (USB) ports to simplify the transfer of test data from the instrument to a computer. For these and many other portable RF/microwave instruments, portability does not in any way mean “compromise.” These are instruments with measurement functions that can easily stand up to much larger, rack-mount instruments in the laboratory, perhaps with only fractions of a decibel in amplitude accuracy separating the two types of instruments. For more details on portable test instruments, check out this article in Microwaves & RF from September 2013.
For RF/microwave engineers in need of on-site testing but with some budget concerns, a number of suppliers offer portable RF/microwave test gear for rent or lease, such as TRS RenTelco (www.trs-rentelco.com), Advanced Test Equipment (www.atecorp.com), Axiom Test Equipment (www.axiomtest.com), and Electro Rent (www.electrorent.com). For example, in addition to an instrument such as the S820E portable spectrum and vector analyzer from Anritsu, TRS RenTelco currently offers deals on rental instruments for a wide range of benchtop and portable test functions, such as frequency counters, power meters, oscilloscopes, logic analyzers, and signal generators, and from leading instrument suppliers, including Anritsu, Keysight, Rohde & Schwarz, Spirent, Tektronix, and Vaunix Technology.