Vector network analyzers (VNAs) may be among the hardest-working and vital test instruments in the RF/microwave industry. They have long been used to measure the amplitude and phase responses of active and passive RF/microwave devices, components, and circuits, generating plots versus frequency that can be very revealing. But VNAs have traditionally also been among the most expensive of RF/microwave test instruments — until now! Anritsu Co. has developed their ShockLine Series of VNAs and the “shock” might be that these simple instruments make accurate RF/microwave measurements without breaking the bank. Designed for testing passive components, ShockLine VNAs are available in two and four-port versions and in a variety of different frequency ranges, as high as 40 GHz. Just add a keyboard, mouse, and a display monitor as needed, and be ready for simple engineering, manufacturing, and cost-sensitive applications with the speed and performance levels of those “more-expensive” analyzers.
The new ShockLine VNAs include the MS46522A VNAs for two-port testing from 50 kHz to 8.5 GHz, the MS46524A VNAs, capable of four-port measurements from 50 kHz to 8.5 GHz, and the ShockLine MS46322A VNAs for two-port testing as wide as 1 MHz to 40 GHz (and many subbands within that range). Unlike traditional VNAs with incorporated keypads, touchscreens, and other accessories, these analyzers are simple in form and format (Fig. 1). They fit into compact 2U-high chassis, which can be easily modified for a rack-mount setup. They are designed for testing passive devices and components, such as antennas, cables, connectors, and filters. They are ready for a wide variety of engineering, manufacturing, and educational applications simply by connecting the VNA to a test controller via a LAN for remote use or to a touchscreen monitor for manual use (Fig. 2).
Users can even select precisely the frequency coverage they need. As an example, the ShockLine MS46522A two-port VNAs are available in two different frequency ranges. One version operates from 50 kHz to 4.5 GHz while the other extends the frequency coverage from 50 kHz to 8.5 GHz. Both units provide full S-parameter measurements on passive devices and components, and either VNA can be used to conduct path-loss characterization of complex systems. Both of these two-port VNAs deliver better than 110-dB dynamic range and corrected directivity of better than 42 dB, with sweep speeds as fast as 70 μsec/point that are sure to keep any manufacturing line moving. The ShockLine MS46522A VNAs can even offer time-domain analysis capabilities when equipped with a time-gating option.
When four-port measurement capability is needed, the ShockLine MS46524A VNAs provide similar performance levels to the MS46522A instruments, but each with two additional test ports (Fig. 3). They are available in the similar frequency ranges of 10 MHz to 4.5 GHz and 10 MHz to 8.5 GHz, and provide similar levels of performance in terms of dynamic range, directivity, and even sweep speeds.
When even greater frequency coverage is needed, the ShockLine MS46322A Series of economy instruments bring two-port passive VNA measurements across a total frequency range of 1 MHz to 40 GHz, for a starting price that suggests a VNA accessory rather than the VNA itself: $12,950 (for the 4-GHz entry-level model). Six models are initially available in the two-port MS46322A Series (Fig. 4), with frequency ranges of 1 MHz to 4 GHz, 1 MHz to 8 GHz, 1 MHz to 14 GHz, 1 MHz to 20 GHz, 1 MHz to 30 GHz, and 1 MHz to 40 GHz.
In terms of test port power, the two-port MS46522A provides –30 to 15 dBm from 0.3 to 6.0 GHz, –30 to 12 dBm from 6 to 8 GHz, and –30 to 10 dBm from 8.0 to 8.5 GHz. The four-port MS46524A offers the same test-power ranges at its test ports, with the additional ports ideal for testing differential cables and multiport devices and components. The two-port MS46322A VNAs simplify power control even further with high and low-state test power levels rather than a range of available power levels. The test-port power in the high state is –3 dBm while the test-port power in the low state is –20 dBm.
The ShockLine VNAs represent a great deal of variety in terms of measurement power and capability (see table), allowing engineers to select suitable measurement power for a current application. In the case of the ShockLine MS46322A VNAs, it is a straightforward solution to upgrade most ShockLine models (except the highest-frequency unit) to a higher-frequency range, so that the capabilities of a VNA system can be modified as needed.
In spite of the differences, the analyzers share many features, which serve them well, such as the use of a local-area-network (LAN) interface, rather than the slower general-purpose-interface-bus (GPIB) connection, for remote control. The VNAs share a common graphical-user interface (GUI) and all use Standard Commands for Programmable Instruments (SCPI) programming code for remote program control. All of the low-cost VNAs perform linear, continuous-wave (CW), and segmented frequency sweeps; in addition, the ShockLine MS46522A and MS46524A VNAs also perform linear power sweeps.
The high-frequency VNAs are supported by measurement receivers using nonlinear-transmission-line (NLTL) sampling for excellent long-term calibration stability and accurate measurements even when working within widely varying environments. Different calibration methods are used among the various ShockLine VNAs, with many sharing waveguide calibrations, line-reflect-line (LRL), line-reflect-match (LRM), short-open-load-through (SOLT), and short-open-load-reflect (SOLR) methods. To reinforce user confidence, each of the VNAs is shipped with a three-year warranty as standard. All of the VNAs offer options for rack-mount capability and time-domain functionality. P&A: $12,950 and up; stock to 4 weeks.